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The purpose of the Signing and Delineation Unit (SDU) Procedures Manual is to provide guidance to the designer, reviewer, project manager and implementer of Signing and Delineation projects. The intent is such that projects are planned, scoped, developed, reviewed, coordinated, documented and constructed the same way regardless of where or by whom the plans are developed. The ultimate goal is to sign and delineate a safe, consistent and reliable transportation network for all users.

1.1 PurposeSDU-01-01Approved

The manual is divided into nine chapters as follows:

  1. Introduction
  2. Principles
  3. Project Delivery Requirements
  4. Signing Design Requirements
  5. Pavement Marking Design Requirements
  6. Special Projects Design Requirements
  7. Quantities
  8. Construction Revisions
  9. NCDOT Project Management Requirements
Each chapter contains sections that describe the major components of each chapter in detail. The subsections include written descriptions, links to other resources, detail drawings, etc. The manual itself is not intended to be a printed manual, but it is to be maintained online such that is it always up to date. To see a list and description of the latest revisions click (here). Individual sheets such as field worksheets and drawings are intended to be printable directly from the PDF.
1.2 How to Use the SDU Procedures ManualSDU-01-02Approved


  • Alternate Route – auxiliary designation assigned to a parallel route of a parent route when both routes are needed to accommodate the traffic demand and when the alternate route has substantially the same geometric and structural design standards of the parent route.
  • Business Route – auxiliary designation assigned to a route that is primarily located within the corporate limits of a city, passes through the business district of the city and reconnects with the parent route beyond the city or congested area.
  • Bypass Route – auxiliary designation assigned to a route that bypasses a city or congested area and reconnects with the parent numbered route beyond the city or congested area.



  • AASHTO – American Association of State Highway and Transportation Officials
  • D-B – Design-Build
  • DPDE – Division Project Development Engineer
  • DTE – Division Traffic Engineer
  • FHWA – Federal Highway Administration
  • GEC – General Engineering Consultant
  • ITE – Institute of Transportation Engineers
  • MPO – Metropolitan Planning Organization
  • MUTCD – Manual on Uniform Traffic Control Devices
  • NCBELS – North Carolina Board of Examiners for Engineers & Surveyors
  • NCAMPO – North Carolina Association of Metropolitan Planning Organizations
  • NCARPO – North Carolina Association of Rural Planning Organizations
  • NCDOT – North Carolina Department of Transportation
  • NCSMUTCD – North Carolina Supplement to the Manual on Uniform Traffic Control Devices
  • NCTA – North Carolina Turnpike Authority
  • NEPA – National Environmental Policy Act
  • NHS – National Highway System
  • PEF – Private Engineering Firm
  • PMU – Project Management Unit
  • PS&E – Plans, Specifications & Estimate
  • RPO – Rural Planning Organization
  • RTE – Regional Traffic Engineer
  • SDU – Signing and Delineation Unit
  • STIP – Statewide Transportation Improvement Program
  • SPOT – Strategic Prioritization Office of Transportation
  • SR – Secondary Road
  • SSRS – Standard Specifications for Roads and Structures (Specs)
  • TEPPL - Traffic Engineering Policies, Practices, and Legal Authority
  • TIP – Transportation Improvement Project

1.3 Definitions and AcronymsSDU-01-03Approved
1.4 ReferencesSDU-01-04Approved
State Traffic EngineerBrian Mayhew, PE, CPM
State Signing Engineer Renee B Roach, PE, CPM
Signing and Delineation Standards Engineer Matt Springer, PE
Eastern Region Signing and Delineation Regional Engineer ​Mitch Eaton, PE
Western Region Signing and Delineation Regional Engineer ​Kelvin Jordan
Division Traffic Engineers               
Regional Traffic Engineers               
Division Logo Coordinators

1.5 ContactsSDU-01-05Approved

​This chapter of the SDU Procedures Manual identifies the principles of signing, delineation, and route designations in North Carolina.  At the legislative level, North Carolina General Statue §136-30 requires all traffic control devices placed on highways, streets, and public vehicular areas to conform with the MUTCD.  The principles described herein are derived from the MUTCD, as well as other sources including AASHTO and NCDOT’s practices and procedures.

2.1 Introduction SDU-02-01Approved

​Signs and markings are traffic control devices used to promote highway safety and efficiency by providing for the orderly movement of all road users on streets, highways, bikeways, and private roads open to public travel throughout North Carolina.

The intent of such traffic control devices is to notify road users of regulations and provide warning and guidance needed for the uniform and efficient operation of all elements of the traffic stream in a manner intended to minimize the occurrences of conflicts and inefficiencies.

To be effective, all signing and marking traffic control devices should meet five basic requirements:

  1. Fulfill a need
  2. Command Attention
  3. Convey a clear, simple meaning
  4. Command respect from road users
  5. Give adequate time for proper response
2.2 Purpose of Signing and DelineationSDU-02-02Approved

Chapter 2B of the MUTCD contains the purpose of regulatory signs and the requirements, conditions and practices for their use.  All regulatory signs shall be substantiated by North Carolina General Statue or ordinance.  Some ordinances are found on the Connect NCDOT – Traffic Safety – Ordinances Website

2.3 Regulatory Traffic Control DevicesSDU-02-03Approved

​Chapter 2C of the MUTCD contains the purpose of warning signs and the requirements, conditions and practices for their use.  Warning signs are to notify road users of a non-apparent condition in a location selected to allow for a reasonable reaction time.

2.4 Warning Traffic Control DevicesSDU-02-04Approved


Route numbers for Interstate and US routes have been assigned by AASHTO and the FHWA.  However, route changes to the Interstate and US numbered routes can be submitted to AASHTO for approval by the NCDOT.  Any route modifications to the Interstate system must be approved by the United States Secretary for the Department of Transportation.  Any modifications to the US numbered routes must be approved by the Special Committee on U.S. Route Numbering of AASHTO. 

FHWA outlines its principles of route numbering in the MUTCD, Section 2D.09 Numbered Highway Systems. In this section, several key points of numbered routes are stated as follows:

  • The intent of numbered systems is to identify continuous routes and facilitate travel along those routes.
  • Overlapping of routes should be avoided.
  • The States have the authority to designate numbered routes within their own jurisdictions.

Section 2D.09 also refers to key AASHTO documents regarding numbered routes:

  • Establishment and Development of United States Numbered Highways
  • Establishment of a Marking System of the Routes Comprising the National System of Interstate and Defense Highways

    These two publications by AASHTO identify the principles of the Interstate and US numbered routes.  Also, included in these documents are the procedures to apply for route changes within the system.


The NCDOT has the authority to manage the numbered route system in North Carolina.  The NCDOT may apply for route changes and extensions of the existing Interstate and US numbered routes and may develop and manage its own state numbered route network.  The NCDOT State Traffic Engineer must initially review all proposed Interstate, US and NC Route changes.

The basic principles of the NCDOT numbered route assignments are:

  • Maintain the principles of the FHWA and AASHTO numbered routes.
  • Add only logical additions to the existing Interstate and US route system.
  • Minimize the number of routes on any given facility.
  • Assign the highest order routes, Interstate routes, to high speed, high capacity freeway facilities serving long distance commerce and travel.  Interstate designated routes shall meet AASHTO requirements for freeways.
  • Assign second order routes, US routes, to high capacity facilities of regional significance or long distance commerce and travel in rural areas.  US designated routes shall meet AASHTO requirements for facility type they are assigned to.  
  • Assign lower order NC routes to lower capacity facilities of local significance, or regional significance in rural areas. 
  • For higher order routes, maintain parallel, lower order, numbered routes for incident management routing where possible.
  • Provide continuity with the path traveled by minimizing the number of turns and exiting maneuvers.
  • Eliminate or reassign routes that conflict with the principles above.
  • Maintain historical route continuity by minimizing requested changes that do not conflict with principles above.

Route Change Guidelines

If an Interstate, US or NC route will be deleted, relocated or established as part of a project a Routing Concept Plan is required.  Notify the Regional Signing Engineer as soon as possible since route changes affect several departments and early coordination is key in determining the appropriate route location and design ramifications.  The following principles and requirements apply for projects that include route designation changes:  

  • Approvals required prior to sign Installation:
Route TypeFHWAAASHTONCDOT Chief EngineerNCDOT State Traffic EngineerDivision EngineerLocal MPO/RPO
InterstateXXXX X
Future InterstateXXXX X
SR    X 


  • The meeting for AASHTO approvals occurs only twice year – Spring and Fall.
  • For Interstate and Future Interstates route changes, FHWA requires Local MPO or RPO approval prior to submitting the application to AASHTO.
  • For US routes, NCDOT requires Local MPO or RPO approval prior to submitting the route change application to AASHTO.
  • For NC routes, NCDOT requires Local MPO or RPO approval prior to submitting the route change application.
  • A Future Interstate is not an official Interstate.  Future Interstate signs indicate an Interstate is scheduled to be there in the future. An underlying route (SR, NC or US route) is required to be in place until officially an Interstate.
  • An Off-Interstate Business Route (Green Shields) is not an official Interstate.  Green Shields indicate the route serves the business area of a city and has a connection to an official Interstate.  An underlying route (SR, NC or US route) is required to be in place.
  • Additional Off-Interstate Business Routes will not be approved.

Interstate Requirements:

  • An Interstate must be on the NHS.
  • The route must meet all current Interstate System design criteria set by the AASHTO “A Policy on Geometric Design of Highways and Streets" or have approved design exceptions.
  • An Interstate will not be accepted by FHWA until reasonably close to completion.
  • The high priority routes in NC are I-42, I-73, I-74, I-87 and the Greensboro Corridor (I-785). 
  • A high priority route can connect to an Interstate on one end and a NHS route on the other. 
  • A non-high priority route must connect to an Interstate on both ends.

Future Interstate Requirements

US Route Requirements:

  • The route must meet all current design criteria set by the AASHTO “A Policy on Design Standards" or have approved design exceptions.
  • US Bypass, Business, or Alternate Routes shall not exist without the regular numbered route.

NC and SR Routes

Additional Resources

Connect NCDOT – Traffic Safety - Route Changes

Numbered Primary Routes in North Carolina Document

2.5 Numbered RoutesSDU-02-05Approved


FHWA outlines its principles of guide sign messaging for expressways and freeways in MUTCD Chapter 2E.  The Chapter establishes that the primary function of guide signs is to provide clear instructions for orderly progress to driver's destinations.  Thus, the selection of the destinations is critical and the presentation of those destinations aids in providing clear instructions.

In urban areas, the destinations for service interchanges should be street names, in lieu of cities. The Chapter further defines the requirements for the designation of destinations, amount of sign legend, supplemental signs and various other guide signs commonly found on expressways and freeways.

For conventional roads, FHWA outlines its principles of destination routing for conventional roads approaching freeway interchanges in MUTCD Section 2D.45.  Sign sequences approaching interchanges on conventional roads should include a destination sign.

AASHTO publishes the list of control cities for Interstates on their website.  This list of control cities is the primary source of destinations for Interstate control cities and is used in conjunction with MUTCD Section 2E.13.02.


The control cities used for signs approaching Interstate routes should be selected from the AASHTO list of control cities for Interstate routes.  For approaches within the city limits of a designated control city, the next control city in each direction should be used for the signs.

For interchanges along freeways and expressways, the selection of the destinations for US numbered routes, NC numbered routes, state maintained secondary routes and city maintained routes is established by the NCDOT.  The NCDOT principles for destination selection are:

  • The number of destinations on any given sign is limited to two, one for each direction of travel from the interchange.
  • In the case of overlapping routes, only one destination should be displayed in each direction for each route.
  • For routes of regional significance, a destination may be a county seat.  Otherwise road names should be used.
  • For non-primary routes, the destination shall be the road name
  • In either direction of travel along a numbered route, a municipality should not be the destination at more than one exit.
  • Unincorporated communities shall not be displayed along freeways or expressways.
  • Supplemental guide signs for traffic generators are governed by the policies and practices outlined in NCDOT TEPPL.
  • See MUTCD Section 2E.35 for additional information on supplemental guide signs for freeways and expressways.

    The intent of these principles is to satisfy the goal of the MUTCD to provide simple and clear instructions.  Not following these principles may result in larger, overly complicated signs that take longer to comprehend – which may inhibit decision making by the traveling motorist.

    Additional Resources:
2.6 Sign MessagingSDU-02-06Approved


AASHTO's Policy on Geometric Design of Highways and Streets defines Route Continuity as providing a route on which changing lanes is not necessary to continue along the through route.  Interchange designs that adhere to route continuity make the driving task simpler by reducing the need for through drivers to change lanes and typically result in simpler signing and improved traffic operations. AASHTO's Policy provides guidance in providing route continuity for typical interchanges.  However, strategies for providing appropriate route continuity are less defined for complex interchanges in the Policy.  Several key principles of lane continuity are as follows:

  • The highway geometry should favor the through movement, not necessarily the heaviest movement.
  • Highway geometry should communicate the through movement to the driver.
  • Highway geometry should maintain its directional character throughout length of its route.  Local variations due to combined routes or increased traffic can increase the number of basic lanes.
  • A through movement should have at least as many lanes as the exiting movement.


Signing and Delineation, Division Traffic Engineers, GEC's and/or PEFs shall review proposed roadway plans for any deviations from the lane continuity key points described above.  This should be done as soon as possible during a project so that the roadway can be changed to the best design possible while minimizing redesign costs and project delays.

Strategies to improve lane continuity include, but are not limited to:

  • Establishment of the proper number of basic lanes for a route.
  • Providing as many lanes for through movements as the exiting movement
  • Providing auxiliary lanes between entering and exiting movements
  • Providing lane balance (the number of lanes beyond the merging of two traffic streams should not be less than the sum of all traffic lanes on the merging roadways minus one.
  • Providing collector distributor roads to eliminate weaving.
  • Providing an additional through lane when an entering traffic stream has two or more lanes

    Additional Resources:
2.7 Lane ContinuitySDU-02-07Approved

​Signing and delineation projects vary greatly - based on the project type, size and complexity.  Generally, project types fall into one of the following categories:

  • Freeway/expressway TIP projects
  • Conventional road TIP projects
  • Special projects
  • Maintenance projects

The managing office or agency may vary as follows:

  • NCDOT central (SDU, Structures, Design-Build, PMU)
  • NCDOT division
  • NCTA
  • Municipality

The designer/engineer of record may be as follows:

  • NCDOT central
  • NCDOT division
  • PEF
  • Municipality

The procurement type also varies as follows:

  • Design – Bid – Build
  • Design – Build & P3

There are a significant number of combinations of project types, managing offices, designers, and procurement types utilized to deliver signing and delineation projects in North Carolina.  Regardless of the means and methods utilized to deliver projects, signing and delineation projects should offer a consistent experience to the public.  The purpose of this chapter is to provide standard project delivery requirements for all projects to achieve a consistent product for all projects across the state.

3.1 Introduction SDU-03-01Approved

​NCDOT Signing and Delineation plans not prepared in house shall be prepared by a PEF that has been prequalified by the NCDOT for the signing and delineation classification codes required for the project.  Project Engineers shall be prequalified as an individual.  This requirement is for all project types, managing offices, and procurement types.  Any GEC's must also be prequalified.  For further information refer to the Transportation Mobility and Safety Division Signing and Delineation Unit Prequalification requirements (Link).

Additional Resource

Connect NCDOT – Prequalifying Private Consulting Firms (Link)

3.2  PEF Prequalification RequirementsSDU-03-02Approved

​Signing and delineation design activities begin during the planning phase and continue through design and construction phases.  Therefore, it is important to assess the project needs early in the timeline.  As soon as a project is identified in the TIP the managing office will identify a preliminary time line for the project.  At this time, a preliminary scoping meeting will be conducted by the managing office to determine the scope of the overall project.

It is important to assess the signing and marking needs of a project early in a project timeline to ensure all-offsite signing and marking work is analyzed with respect to right of way, utilities, noise walls, traffic control and project limit extents.

During project planning, signing and delineation requirements should be evaluated according to the following (as required by project type):

  • Routing concept: For projects that include Interstate or US route changes
  • Interchange Access Request (IAR) Signing Concept:  For projects requiring an IAR, a conceptual signing and lane continuity figure showing the interchanges analyzed in the IAR shall be developed.
  • Proof of Concept: For project types defined below, a preliminary signing concept should be developed during the NEPA phase:
  • Interstates
  • Urban Loops
  • Toll Roads and Bridges
  • Express Lane Projects

For projects that do not have signing and delineation tasks during planning, the agency managing office shall identify a designer or select a PEF to carry out the final design plans for signing and pavement markings upon acceptance of the 25% preliminary roadway design plans.  The PEF shall be under contract through construction to incorporate all field verifications.

This following link provides timelines and process maps for planning and design activities of several different types of typical projects. (Link)

Additional Resource

NCDOT Project Flow Chart Generator (Link)

3.3 Project TimelineSDU-03-03Approved

​Coordination with other Units within NCDOT and outside NCDOT is required for most projects and is the responsibility of the Designer or the PEF.  All coordination shall be documented and provided to NCDOT at the culmination of the project.  All coordination meetings shall be documented with meeting minute notes.  The major coordination points are tabulated here: (Link).

3.4 Coordination RequirementsSDU-03-04Approved

​All signing and delineation work shall be prepared in accordance with the NCDOT or PEF's quality assurance/quality control standards (QA/QC).  The firm or agency that prepares the plans is responsible for the quality control process.  Reviewing agencies or GECs are not responsible for QA/QC of the designer's product.  Quality Control principle requirements for signing and delineation projects are as follows:

  • The designer shall adhere to a documented QA/QC process.  The NCDOT's QA/QC standard may be found here (Under Development).
  • For signing design plans, the designer should use NCDOT's three person check (3PC) method for checking plans prior to all submittals.  The 3PC method is described in Chapter 4.
  • All QA/QC reviews should be performed by someone prequalified to do signing and pavement marking plans.
  • Agency/GEC reviewers are responsible for review of general adherence to the project's scope, compliance with standards (MUTCD and NCDOT) and the Signing and Delineation Unit Procedure Manual.  Guidance for reviewers may be found in Chapter 9.
3.5 Quality Control RequirementsSDU-03-05Approved

​The project timeline above outlines deliverables for each milestone.  The submittal requirements for the final design milestone submittals are available on the Signing and Delineation Website (Link). All plans and submittals shall include submittal requirement checklists provided in Chapter 4 and 5 for Signing and Pavement Marking respectively.  Checklists are a required element for each submittal.

3.6 Submittal RequirementsSDU-03-06Approved

​Some Division Design TIP projects will require Signing and Delineation review and/or coordination.  The level and type of coordination is based upon several factors such as the location (i.e. interstate projects or freeways), complexity of the project (i.e. CFIs or multi-lane roundabouts), or design elements (overhead structures).  Refer to the NCDOT Division Design Projects Signing and Delineation Unit Coordination Requirements for more details (Link).

3.7 Division Design Projects and  SDU CoordinationSDU-03-07Approved

​All NCDOT TIP Design Bid Build projects are to utilize the SharePoint Application to store all non-confidential project related materials.  The site is to be used for Signing and Delineation consultant plan submittals.

Additional Resource

Preconstruction SharePoint Application Memo (Link)

3.8 SharePoint ApplicationSDU-03-08Approved

​All signing and delineation plans and special provisions shall be signed with electronic signatures in accordance with the NCODT eSignature policy and NCBELS requirements.  All PDFs are to be named using the approved naming convention found in the Design Guidelines referenced in Chapter 3.6.  All PDFs shall be formatted using the formatting guidelines in the Design Guidelines referenced in Chapter 3.6.

Additional Resources

NCDOT eSignature policy (Link)

NCDOT Digital Signatures on Let Plans Presentation (Link)

NCDOT Final Plan Submittal Changes (Link)

3.9 NCDOT eSignature ProceduresSDU-03-09Approved

​This chapter of the SDU Procedures Manual provides detail on the preparation of Signing, Plans prepared for the NCDOT or to NCDOT standards.  This section is organized to present general signing plan information first, followed by specific signing plan elements in the order those elements appear in a set of signing plans.  The details described herein are derived from the MUTCD, as well as other sources including AASHTO and NCDOT's practices and procedures.

4.1 IntroductionSDU-04-01Approved

​NCDOT classifies signs by type based on the size, fabrication method, support type and purpose. The parameters of the different NCDOT sign types are described in Table 901-1 of the NCDOT Standard Specifications.  The following further clarifies sign types:

Type A:  The purpose of Type A signs may be guidance, regulatory, or warning.  They are large signs fabricated from multiple sheets of aluminum with attached Z"-bars on the reverse.  They may be erected on overhead sign structures, structural steel or wood posts. 

Type B:  The purpose of Type B signs may be guidance, regulatory, or warning.  They are fabricated from one sheet of aluminum with attached Z"-bars on the reverse.  They may be erected on overhead sign structures, structural steel or wood posts.

Type D: The purpose of Type D signs is primarily guidance.  They are fabricated from one sheet of aluminum with holes for bolting to supports on the reverse.  They are erected on steel U-channel posts, square tube posts (manufacturer spec) or wood posts.  The recommended maximum square footage (u-channel) is 24 sf. Three u-channel post installation should be outside of clear recovery area or behind guardrail.

Type E: The purpose of Type E signs may be regulatory or warning.  They are fabricated from one sheet of aluminum.  Legends and borders are silk-screened or reverse silk-screened.  They are erected on steel u-channel posts, square tube posts or wood posts. 

Type F (Route Marker Assemblies): The purpose of Type F signs is guidance.  They may be an assembly of individual panels.  Each panel requires only one sheet of aluminum to be fabricated.  Legends and borders are silk-screened or reverse silk-screened.  They are erected on steel u-channel posts, square tube posts, steel beams or wood posts.  The recommended maximum square footage (u-channel) is 24 sf (elaborate or confirm).

Milemarkers (Reference Location Signs): The purpose of Milemarkers is guidance.  They are fabricated from one sheet of aluminum.  They are erected on steel (2lb) u-channel posts, square tube posts or wood posts. 

Overlays: The purpose of Overlays is to amend an existing sign message.  They may be installed on existing overhead or ground mounted signs and may require more than one sheet of aluminum.  They are attached to an existing sign with rivets. (Include limits/ criteria of overlays)

Sign Numbers:

  • 1-99: Type A or B signs erected on overhead sign structures
  • 100-199:  Type A or B ground mounted signs  
  • 200-299:  Type A or B signs exit gore signs
  • 300-399: Type D Signs
  • 400-499: Type E Signs
  • 500-599: Type F Sign Assemblies
  • 600-699: Overlays
  • 700-799:  Proposed Type A or B signs on existing supports
  • 900-999: Existing Type A or B signs erected on proposed supports

Milemarkers are not assigned numbers.

Consistent numbering helps in the fabrication and review of signs.

Each Type A and B sign is assigned a unique number (1, 100, 200, 700, 900) as the sign number also identifies a location.   If a Type A or B primary sign has additional secondary or supplemental panels attached or mounted to it, all panels are assigned the same base number and a unique letter, starting with “A" for the top panel. 

Example: a primary guide sign has a secondary exit number panel and a supplemental LODGING panel.  The Exit number panel is sign number 101A, the primary sign is 101B and the supplemental LODGING is 101C.

Every instance of a particular Type E Sign (stop sign, yield sign, etc.) of the same design and size shall be assigned the same number. If a type E sign is of the same design as another but of a different size, it shall be assigned a different number. If mounted on the same support, all unique Type E signs shall be assigned a different number.


A Wrong Way and a Signal ahead sign are mounted back to back on a steel u-channel post.  The Wrong Way sign is 401 and the Signal Ahead sign is 402.

For Type F Signs, number 501 is assigned to an entire assembly of route markers panels and auxiliary panels.   Each Type F location is assigned a unique number.

Relocated Type D, E and F signs are not assigned numbers.

If more than 100 numbers are needed for a particular range of numbers, a four-digit number shall be used for the whole range.  Example: 1000-1999 for overhead signs.

Sign Number Assignment Order

To assign sign numbers, on each individual Signing Plan Sheet (or can number from left to right on strip map), number from left to right in one direction of travel of the - L- line.  At the end of the plan sheet, number from right to left for opposite direction of the - L- line.  For the - Y- Lines, start with the lowest numbered - Y- Line and number from bottom of plan sheet to top (one direction only) and from top to bottom of sheet.

4.2 NCDOT Sign TypesSDU-04-02Approved

​All NCDOT signing plans shall contain the same information, in the same format, whether they are produced by the NCDOT SDU, a Division, a Municipality, or a PEF to assist with review and sign fabrication/construction.  Signing and Pavement Marking plans should be separated on all projects. Any deviation will require NCDOT approval. The general signing plan elements are as follows and shall appear in this order in all plans if required:

  • Title Sheet
  • Key Sheet (optional, include for urban/ complex projects)
  • Ground Mounted Support Designs
  • Overhead Sign Structure Drawings
  • Type A, B and D Signs (Sign/Panel Designs)
  • Type E Signs
  • Type F Signs
  • Milemarkers
  • Overlay Design and Placement Details
  • Existing Signing Plan Sheets (combine Existing and Proposed if possible)
  • Proposed Signing Plan Sheets

Page Numbering/Lettering

All Signing sheets should use the “SIGN-“prefix.  The sheet numbering should use the following format:

  • SIGN-1: Title Sheet, Note Sheets, Key Sheet
  • SIGN-2: Ground Mounted Support Designs
  • SIGN-3: Overhead Sign Structure Drawings
  • SIGN-4: Sign Designs and Overlay Placement Details
  • SIGN-5 Signing Plan Sheets

If certain elements are not required, the next element shall use the number of the element that is not used.

Example: If overhead structure drawings are not required, then the panel designs shall begin on SIGN-3.

If additional sheets are needed for SIGN-1, 2, 3, 4, and 5, letters shall be used for any additional sheets.  If additional letters beyond “Z" are needed, double, triple and quadruple letters shall be used.

Examples: SIGN-3 is followed by SIGN3A.  SIGN-3Z is followed by SIGN-3AA.  SIGN-4ZZ is followed by SIGN-4AAA

Regulatory and Warning Designs shall be on separate sheets from other Sign Designs unless otherwise specified below.  Route marker assemblies shall be separate sheets from other types of sign designs unless otherwise specified below.  Reference Marker Sign Designs shall be on separate sheets from other Sign Designs unless otherwise specified below.  For projects with very few sign designs, all types of sign designs may be shown on the same sheet including on the title sheet for very small projects.

Existing Signing and Proposed Signing Plan Sheets may be shown on separate design sheets (if combining would cause too much clutter) unless otherwise agreed upon during the scoping process.  For any additional Existing Signing and Proposed Signing Plan Sheets, the next numerical number shall be used.  When separated, the Proposed Signing Plan Sheets shall be after all the Existing Signing Plan Sheets and begin with the next number after the Existing Signing Plan Sheets.  If, after design has been started, additional Existing Signing Plan Sheets and Proposed Signing Plan Sheets are needed, letters shall be used to insert sheets into the plan set such that the inserted sheets fall in a logical progression.

4.3 Plan ElementsSDU-04-03Approved

​The title sheet identifies the package of plans as a set of signing plans.  It is used to provide the general project information as well as project specific details to reviewers, the contractor, inspector and future designers.

Title Sheet Elements

  • TIP Number
  • Contract Number
  • Vicinity Map – a general map that shows the Interstate, US, Primary and Secondary Routes in a large enough area to locate the project.  Required if there is no Roadway plan set.
  • County and Location information - description taken from the Roadway cover page
  • General Notes – a list of notes that can apply to all projects; the Engineer may add or modify notes to this list as necessary as they apply to the signing plans as a whole (included on Seed Files)
  • Pay Item Notes – a list of project-specific pay items as they are written in the Measurement and Payment subsection in each Section of the NCDOT (Specs) or in the Measurement and Payment subsection of a Project Special Provision.  Only the pay item notes required for a project shall be included.  Pay item notes shall be given a unique number, ordered by the Description number from the latest Pay Item List shown on Signing and Delineation Seed Files.
  • Project Notes – brief descriptions of work necessary to convey specific construction details to the contractor.  Project notes are used to expand upon the Construction Method subsection of the NCDOT SSRS of a particular pay item note.   Project notes shall not be used to delete or modify any part of the Standard Specifications for Roads and Structures.
  • Roadway Standard Drawings – A list of all applicable signing-specific Roadway Standard Drawings shall be listed on the title sheet. 
  • Quantities – A list of all signing quantities shall be listed in numerical order by Description number as they appear in the 2018 Transport Pay Item List. Do not include any state furnished quantities in the summary of quantities.
  • Sheet Index – a list of signing sheets by element type
  • Contact Information – a list of applicable contact information such as the Signing and Delineation Regional Engineer, Signing and Delineation Project Engineer, Design-Build Squad leader, Division Traffic Engineer, Regional Traffic Engineer.  If the Signing and Delineation Unit does not review the plans, they shall not be listed on the title sheet.
  • Firm Information – If prepared by a PEF, the title sheet shall contain the PEF name, address, NCBELS License number and main office number.  A non-colored logo may be included.

Additional Resource

Title Sheet Example and Description

4.4 Title SheetSDU-04-04Approved

​A key sheet is used on complex projects or when the Signing Plan Sheets do not follow an intuitive order.  One drawing should the location of each Proposed Signing Plan Sheet. 

Additional Resource

Key Sheet Example and Description

4.5 Key SheetSDU-04-05Approved

​Ground Mounted Support Designs for Type A and B Signs are based on sign size, wind load, support length, and other information.  All sign supports for Type A and B ground mounted signs shall be designed using the NCDOT Sign Support Selection Tool available on the NCDOT Signing and Delineation website.  The tool is used to select the proper steel beam or wood supports per the latest edition of the AASHTO's LRFD Specifications for Structural Supports for Highway Signs, Luminaires, and Traffic Signals. 

Simple Supports

Simple supports are one-piece steel beams set in concrete footings.  All Type A and B ground mounted signs on simple (non-breakaway) supports shall be protected by guardrail, barrier or another form of approved positive protection. The minimum lateral distance between the face of the guardrail and the closest sign edge shall be six feet.  The signing project engineer shall coordinate with the roadway engineer such that positive protection is provided at all proposed simple support locations.

Breakaway Supports

Steel beam breakaway supports are beams considered to be breakaway per AASHTO and FHWA requirements.  They are typically made up of three beam sections with hinges and slip bases and are set in a concrete footing.  The top section is from the top of the sign panel to the hinge, which is at the bottom of the sign.  The middle section is from the bottom of the sign to the slip base.  The bottom section or stub is embedded in the footing.

When signs are installed on breakaway supports on freeways, the minimum lateral offset for Type A and B ground mounted signs on breakaway supports should be 30 feet. Signs can be moved as close as 18' without guardrail protection.  The desired offset for Type A and B signs on ramps is 18' for shoulder sections and 12' for curb and gutter sections. If unable to obtain desire spacing, reference MUTCD 2A.19 (Link)

Wood Supports

Wood supports may be used for temporary or permanent sign installations.  Wood supports shall be protected by guardrail, barrier, or another form of approved positive protection if they are not considered to be break-away.  Wood supports are considered to be breakaway supports according to the information below:

  • 4" x 4" wood posts can be used at any location, without guardrail protection.  Two 4" x 4" posts can be spaced closer than 7' apart.
  • 4" x 6" wood posts must be used with guardrail or drilled to make them breakaway. Two posts can be spaced closer than 7' apart. 
  • 6" x 6" wood posts must be used with guardrail or drilled to make them breakaway. Two posts must be at least 7' apart when used as breakaway. 
  • 6" X 8" wood posts must be used with guardrail or drilled to make them breakaway. Two posts must be at least 7' apart when used as breakaway. 
  • 8" X 8" wood posts or larger are not considered breakaway even if drilled. These posts must be behind guardrail. 
  • LVL  (Laminated Veneer Lumber) posts can be used as breakaway up to 8" X 15". See Roadway Standard Drawing 903.20.

Support Design Cross Sections

Typically, for TIP projects, support designs are preliminary, and verification is required prior to construction.  The designs are estimated using the roadway design cross sections or measurements from a site visit to the proposed locations.  If the sign location is within the roadway cross section limits, the roadway cross section should be used.  If the sign location is outside the roadway cross section limits, data from field measurements should be used.  The cross section shall have the sign number, sign sizes, project, county, alignment and station, sign offset, support offsets, and s-dimensions shown on the cross section. The PEF is also required to submit the individual worksheet for review.  Both are submitted with each submittal starting with the 50% plans.

The s-dimension for ground mounted signs represents an increase (+) or decrease (-) in support length relative to the elevation of the edge of the outside travel lane, not the outside edge of the paved shoulder.

Support Design Worksheets

Information collected in the field or obtained from the cross sections shall be entered into the latest NCDOT Support Selection Tool.  The support design tool includes specific instructions on the first tab of the Excel program.

The design must pass all tests including the following as specified by AASHTO (See AASHTO, Roadside Design Guide, Section 4.3.2 for details):

  • Mounting Height Test – The hinge shall be at least 7 feet above the ground and should be no more than 10 feet above the edge of travel unless approved by the managing unit. Any deviation needs to be approved by NCDOT. (Max (-) negative s-dimension of -3)
  • A single post, if 7 feet or more from another post, should have a weight per foot ratio of less than 45 lb/ft.
  • If breakaway, the total weight below the hinge, but above the shear plate of the breakaway base, shall not exceed 600 pounds.
  • For two posts are spaced less than 7 feet apart, each post should have a weight per foot less than 18 lb/ft.
  • Support Spacing Test – When 3 supports are needed, the distance between them cannot be less than 3.5 ft.

    The support safety test does not apply to simple supports. (Simple supports are protected by guardrail.)

Steel and Wood Support Chart Sheet(s)

The support selection tool tabulates the selected supports, footing designs and quantities on two summary tabs at the end of the workbook.  One worksheet is provided for signs erected on wood supports, and one worksheet is provided for signs erected on steel supports.  If applicable, these two tables shall be copied and pasted directly into the signing plans.  As field verifications are performed, these tables shall be updated with the final sign sizes, field verified sign locations, field verified “S" dimensions and field verification dates.

Each support chart sheet shows the version of the support selection tool used and the release date.  For each sign location, the support chart sheet shall show the sign number, sign type, sign size, roadway station, number of supports, beam section size, type of sign support, offset from the edge of travel lane, sign attachment method (if applicable), support spacing, sign support S dimensions, lengths, weight, and the amount of concrete needed for the support footings.

The support chart sheet shall include the above information for all proposed signs on proposed supports (100 and 200 series signs), proposed signs on existing supports (700 series signs), and existing signs being relocated to proposed supports (900 series signs).

The support chart sheet shall contain the typical elevation detail for ground mounted signs and the detail for exit gore sign offsets.

Post Letting Updates (“s"-dimension verifications)

The “s"-dimensions and support lengths detailed in the plans are used for estimating purposes and are not to be used for fabricating supports.  Prior to sign support fabrication, the s-dimensions shall be verified by field measurements and shall be submitted to the managing unit for review.  With the support verification data, the support selection is finalized and a construction revision is completed by either the PEF, if under contract, or the managing unit. Without field verification, signs may be required to be field drilled and any sign damage sustained will be contractor's responsibility.

Prior to establishing the final s-dimensions, stake the horizontal location of the proposed signs for the Engineer's review.  Perform a thorough investigation of the proposed sign locations (confirm R/W) or revised locations established during the Engineer's review.  Identify any obstructions, either existing or proposed, which may interfere with the proposed sign installation.  Such items may include, but are not limited to, existing or proposed drainage systems, underground and/or aboveground utilities, and drainage ditches.  If adjustments in the sign locations are warranted to avoid obstacles, advise the Engineer in writing. Include a detailed sketch of the proposed sign location, the obstruction and the new location recommended to avoid the obstruction.  Do not revise any sign locations without the written direction of the Engineer.

Additional Resources

NCDOT Support Program (Link)

Ground Mounted Sign Cross Section Example

Ground Mounted Sign Support Selection Worksheet Example

Link to Construction Manual (Link)

Applicable Standard Specifications


Applicable Standards


4.6 Ground Mounted Support DesignSDU-04-06Approved

Overhead Sign Structure Drawings Sheets

An overhead sign structure drawing is required for each proposed overhead assembly and each existing overhead assembly with proposed sign panels. This drawing shows the roadway cross section and a schematic of the overhead sign structure.  Cross sections are obtained from roadway plans or field shots.  If the overhead sign structure is designed where roadway cross sections are not available, the design shall be based on field data.  Overhead Sign Structure Drawing Sheets shall include the following:

  • Overall structure length
  • Lane, gore and shoulder widths
  • Lane arrows
  • Pavement and ground slopes and dimensions
  • Support offsets
  • S-dimensions at support locations
  • Positioning of proposed and future signs relative to travel lanes
  • Spacing between proposed and future signs
  • Sign messages and/or future messages
  • Future signs
  • Minimum and maximum vertical clearances
  • Existing and proposed guardrail, guiderail, barrier, noise walls, and retaining walls
  • Labeling of facility and direction of travel
  • Wind load and dead load requirements to be used for proposed structures and footing designs
  • Drainage pipe size, type and offset
  • Right of Way
  • Utility lines and offsets
  • All applicable notes.

Sign Placement

Place signs over the travel lanes to which they apply.  (Down Arrow according to MUTCD) Down arrows shall be placed centered over the lane to which they apply.  Down arrows may be centered up to 2' from the center of the lane if needed.  Signs shall not be closer than 0.5' from an adjacent sign.  Any sign for the next downstream interchange shall be 0.5' from the exit direction sign for a right exit and centered over the left lane if a left exit.  Confirmation (pull through) signs shall be centered over all through-lanes that continue beyond the next exit.  Exit Directional signs should be centered over the corresponding lane if structure spacing allows. Exit panels shall be right justified with the primary sign for right exits and left justified with the primary sign for left exits.

Maximum Length

The maximum length for a full span overhead assembly without a center support is 190'. The maximum length for a cantilever support is 52'.

Vertical Clearance

Overhead signs and proposed wind loads require a minimum vertical clearance of 17 feet and maximum vertical clearance of 18 feet from the high point.  (Elaborate for sight distance for overhead signs close to signals and bridges)

Lateral Offsets

If guardrail is not included in the Roadway Plans but is required for an overhead sign, a written request for additional guardrail should be made to Roadway Design/PMU/ whoever is responsible. The overhead support and footing should not be located in a ditch bottom as this can obstruct drainage flow.  Provide 3' of clearance from the ditch bottom whenever possible.   

A chart is provided in the additional resources with guidance on support offsets and guardrail requirements. This chart is intended as a guide and does not replace the AASHTO Roadside Design Guide.

Supports in Barrier

When designing overhead supports to be mounted on median barrier, close coordination between Traffic Engineering and the roadway designers is required. The Structure Design Unit will prepare all details for median barrier supports and these details will be included in Roadway Plans for design and transition of the barrier.   

Existing Overhead Structures

Existing structures may be utilized for proposed overhead signs.  Proposed signs may be added to existing overhead sign structures if the signs proposed do not exceed the design wind load area for the structure. (Consider the age of the structure before determining if existing structure may be utilized.) Prior to modifying an existing overhead sign assembly to accommodate proposed signs that exceed the original wind load area, a structural analysis of the overhead sign structure shall be performed.  All existing overhead sign assemblies determined to be structurally inadequate for the proposed modifications shall be replaced.  An existing overhead sign assembly may be modified to accommodate proposed signs that do not exceed the original wind load area without performing the aforementioned structural analysis.

When the structural analysis determines that an existing overhead sign structure is structurally adequate to be retained or the proposed wind load area does not require a structural analysis, proposed signs may be designed to be installed on existing overhead structures.  Any pertinent existing overhead signs shall also be replaced, unless otherwise directed by the NCDOT.  Structure Drawings for existing overhead structures with new sign panels shall depict the following:

  • The existing sign sizes;
  • The new sign designs;
  • The vertical clearance of all new signs;
  • The new signs' positioning over travel lanes;
  • The original wind load area;
  • The original design information such as the TIP number and the structure letter.

If the Department is unable to provide existing overhead structure drawings or shop drawings of the existing overhead sign structure, a new overhead sign structure shall be designed and installed, and the existing structure shall be removed and disposed of.

The minimum vertical clearance beneath all existing overhead sign assemblies that are retained shall be 17 feet.

Wind load

The 50-year mean recurrence 3-second gust wind speed shall be used in the design of the structure. The wind load numbers are obtained from the Standard Specification for Structural Supports for Highway Signs, Luminaries, and Traffic Signals.  No counties in North Carolina have design speed below 90 mph. (See sheet 29 or 30 for wind speed)

Proposed Wind Load Area

Overhead sign structures shall be designed for proposed and future signs. The designer shall determine maximum wind load areas and include the wind load areas on the overhead sign structure drawings. The wind load area for the sign structures shall be determined according to the following: 

  • Case A - Identified Future Signs: For sign structures that have an identified need for larger future signs shown in the plans, the future signs shall be designed and shown on the overhead sign structure drawings. Future sign messages, sizes, and positions shall be shown on the elevation drawings.
  • Case B - General Future Wind Load Area: For overhead signs without identified future signs shown in the plans, the structure shall be designed for a larger wind load area to accommodate future signs that are not identified at the time of the structure design. General future wind load area sizes and positions shall be shown on the elevation drawings. The general future wind load area shall be computed as follows:
    • Shape: The wind load area for each group of primary, secondary, and supplemental signs shall be rectangular.
    • Width: The wind load area shall extend 2' outside the proposed primary sign width on each side of the sign.  In cases where two wind load areas intersect, the taller area shall be used.  For cantilever structures, the wind load area shall be flush with the edge of the primary sign at the cantilevered end, such that the wind load areas do not extend past the end of a cantilever sign structure. (Extends 2' or 4' on right side for cantilever)
    • Height: The wind load area shall extend 2' below the bottom of each sign and 2' above the top of each sign, including secondary signs, supplemental signs, and the vertical space between signs according to Roadway Standard Drawing No. 904.20.  The minimum vertical clearance shall be measured from the bottom of the lowest wind load area.
  • Case C, Exceptions from Case B: The following are exempted from Case B, general future wind load areas:
    • Arrow Per Lane Signs
    • Interchange Sequence Signs

Archiving of Overhead Sign Structure Design Information


Information related to the design of each overhead sign structure (full-span, cantilever, pedestal mount) should be archived to be retrievable at any future date.  This information is often requested for the analysis of an existing overhead sign structure if there are proposed modifications that will differ from the original design layout and loadings.  Modifications may include the replacement of existing signs with larger signs or repositioning of existing signs on the structure.

The Structure Design Unit maintains a database for providing NCDOT with the ability to capture bridge inspection and inventory data, which is known as the Wearable Inspection and Grading Information Network System (WIGINS) system.  Design information for overhead sign structures can be archived within this database.  The five design elements that is of interest for archiving is:

  • Sign Structure line drawings (Field Verified)
  • Sign Designs
  • Plan Sheets that include Overhead Assemblies
  • Sign Structure Fabrication Drawings approved by Structures Design Unit
  • Foundation Footing Details approved by Structures Design Unit

During the design and construction phases of a project, the NCDOT Signing Project Engineer shall ensure the archiving of design elements of interest they are responsible for electronically within the Project Folder on NCDOT Connect, in PDF file format.  If there have been revisions made during the construction of the project that affected signing elements, the most up-to-date revised design and plan sheets shall be used.  Structures Management Unit will be responsible for archiving of approved Fabrication Drawings and Foundation Footing Details.

If the Signing Project Engineer is not provided any of these items either through a paper or electronic copy, they should make the attempt to solicit copies of these items from the appropriate designer or other sources.

Collection and Recording of Sign Structure Design Data

Signing Project Engineers typically are involved in the design or review of projects that may contain proposed overhead sign structures.  These project types include:

  • State Transportation Improvement Projects (STIP)
  • Design-Build Projects
  • Division Design Raleigh Let Projects
  • Division Purchase Orders Contracts
  • Spot Safety Projects
  • Turnpike Projects

Prior to or at the 90 Percent plan submittal, the Signing Project Engineer shall submit to the NCDOT Structures Unit; Structure, Inventory, and Appraisal group (SIA) a spreadsheet listing all proposed overhead sign locations (link for sample spreadsheet​).  The spreadsheet should be completed by the NCDOT Signing Project Engineer or included within a Firm's Scope of Work for completion and submitted to  The SIA group will assign each structure its Structure Inventory number using the information in the spreadsheet and return that information to the Signing Project Engineer.   Note that the inventory number is based on the county the structure resides in and an assigned item number.

Example: Structure 250479 has a county code 25 for Cumberland County, and 0479 is the assigned inventory item number.

The Structure Inventory number shall be included on the final sealed structure line drawing. Geographic coordinate information of the proposed sign structure's location shall be included in the excel spreadsheet but do not have to listed on the structure line drawings.  Coordinates should be taken near the center of the structure and reference its approximate Latitude and Longitude.

Once the Structure Inventory number has been provided, the Signing Project Engineer shall also add each overhead structure to the corresponding project's SharePoint Connect site under Project Structures. This generates a list of all structures (overhead signs, bridges, culverts, walls, etc.) that need to be accepted by the Department at the completion of the project.

Removal of Archived Overhead Sign Structure Design Information


Design projects may include the complete removal and disposal of existing overhead sign structures.  This may be related to the widening of an existing roadway that will compromise the foundations of existing overhead sign structures, or the proposed area of sign panels may exceed an existing structure's design criteria.  Removal of these existing overhead sign structures should be relayed to the NCDOT Structures Unit; Structure, Inventory, and Appraisal group, as this group maintains the database for providing NCDOT with the ability to capture bridge inspection and inventory data, which is known as the Wearable Inspection and Grading Information Network System (WIGINS) system.

Removal of Data within WIGINS

Removal of information from WIGINS for the disposed overhead sign structure will be performed by the Structure, Inventory, and Appraisal group.  Prior to the 90 Percent plan submittal, the Signing Project Engineer shall submit a spreadsheet listing all existing overhead sign locations proposed for removal and their appropriate Structure Inventory number.  The spreadsheet may be submitted to  The Structure, Inventory, and Appraisal group will determine the appropriate time to remove and archive the existing overhead sign structure data from WIGINS.

Verification of the Structure Inventory numbers can be obtained from the NCDOT ArcGIS Map  under the Structures layer; the Highway Division Traffic Engineers office; or from the Structure, Inventory, and Appraisal group.


Lighting is no longer required on proposed NCDOT overhead sign structures.  Any existing sign structure on a project that is to be retained, should have the existing lighting, walkways, and lighting electrical service removed, and all sign panels should be updated to NCDOT's current sheeting requirements.

Include reference and description for SP for Cutting of Sign Hangers


Coordinate with the ITS section of Traffic Mobility and Safety Division for the location of any existing, relocated or proposed DMS structures. All DMS structure drawings shall be shown in the ITS plans. Ensure minimum distance between DMS structures and guide signs are maintained.

Additional Resources
Proposed Overhead Sign Structure Line Drawing Examples (Link)
Existing Ground-mounted Structure Drawing Example
Lateral Offset Guidance for Overhead Support Design
NCDOT Construction Manual - Determination of “S"-Dimensions  (Link)

Applicable Standard Specifications

4.7 Overhead Sign Structure DrawingsSDU-04-07Approved

​All Sign Designs shall be shown in the plans.  All signs that do not have a standard panel design in the MUTCD Standard Highway Signs (SHS) manual shall have a panel layout with an NCDOT sign panel report shown in the plans.  The sign designs and panel reports shall be prepared using the latest version of GuideSign software or Openroads Designer and the latest NCDOT Panel Reports.  For signs with a standard panel design in the MUTCD SHS, the size, color (if applicable), and mounting type shall be shown on the plans. Panel designs that are not provided in the MUTCD SHS, shall be designed by the engineer and approved by NCDOT.

Type A, B, D and Overlay sign designs shall contain the sign number, sign size, type of sign, quantity, total area of the sign, type of border, background color, copy color, symbol size and location, material thickness, spacing factors, number of Z-bars, the applicable notes for fabricating the sign and the letter spacings.  Letter spacings shall be measured to the start of the next letter. Provide a detail to assist with installation.

Sign Colors

If not specifically addressed in the MUTCD SHS, signs shall be designed according to the following criteria.  If a SHS design exists, that standard shall take precedent over the following criteria.

The MUTCD specifies sign color based on sign purpose in Section 2A.  Unless identified in the MUTCD SHS, the color of each sign shall be specified on Sign Design sheets of the plan set.

RED - stop, yield, or a prohibition. Examples include WRONG WAY, DO NOT ENTER, and   NO PARKING.

GREEN - indicates movements permitted, or directional guidance. Examples include directional signs or permissive parking regulations.

YELLOW - general warning such as MERGE, or LANE ENDS.

BLUE - general services, logos leading to motorist services such as lodging, food, or gas, and hospitals with 24 hour emergency care.

BLACK on White - regulatory signs. Examples include ONE WAY, KEEP RIGHT, and SPEED LIMIT.

ORANGE - construction and maintenance work zones. They warn drivers of unusual conditions and of people and machines working on or near the roadway.

BROWN - recreational and cultural facilities signs.

Fluorescent Yellow-Green - warning signs, such as SCHOOL CROSSING, PEDESTRIAN, and BICYCLE.

Fluorescent Yellow - warning signs, such as RAIL CROSSING. 

Additional Resources

MUTCD Table 2A-5 (Link)

MUTCD Standard Highway Signs (SHS) (Link)

Sign Sizes

Sign heights and widths shall be in increments of 6". Follow the MUTCD SHS and NCDOT signing typicals as close as possible and increase the line spacing or outer edge spacing to maintain a 6" increment.  See MUTCD Section 2E.15 for guidance on interline and edge spacing for guide signs on expressways and freeways.

Unless otherwise approved by the SDU:

  • Interline spacing of upper-case letters should be approximately three-fourths the average of upper-case letter heights in adjacent lines of letters.
  • The spacing to the top and bottom borders should be equal to or greater than the letter height of the largest adjacent line of letters.
  • The lateral spacing to the vertical borders should be equal to or greater than the height of the largest letter.

Additional Resources – Freeway and Expressway Guide Signing

MUTCD Section 2E.15 Interline and Edge Spacing. (Link)

Link to MUTCD SHS Design Guidelines

Letter Series

Letter series for the standard alphabet are B, C, D, E, Emod and F.  Lettering for names of places, streets, and highways on guide signs shall be mixed case (upper and lower) and use the D or Emod series depending on the letter height.  Letter heights up to and including 8" shall use the D series.  Letter heights at 10.67" and above shall use the Emod series.

All other lettering on guide signs shall be all capital letters and use the E series.  Legends on regulatory and warnings signs shall be all uppercase letters and can utilize any letter series except Emod.

Interline spacing for messages using mixed case letters with underhanging letters (g, j, p, q, and y) shall be increased according to the following chart:



For messages with hyphens, the spaces on either side shall be half the height of the uppercase letters.  Example: Winston - Salem    16"/12" Emod letters – spaces before and after the hyphen and the hyphen will be 8" each.

Additional Resources

MUTCD Section 2D.05 Lettering Style (Link)
MUTCD Section 2E.14 Size and Style of Letters and Signs (Link)

Letter Height

Letter heights shall be large enough to provide necessary legibility distance, with a specific ratio of 1 inch of letter height for every 30 feet of legibility distance.  For a general letter height discussion, refer to MUTCD Section 2A.13.  For letter heights on guide signs on conventional roads, refer to MUTCD Section 2D.06.  For letter heights on guide signs on expressways, refer to MUTCD Tables 2E-2 and Table 2E-3. For letter heights on guide signs on freeways, refer to MUTCD Tables 2E-4 and Table 2E-5.


Additional Resources - Conventional Road Guide Signing

MUTCD Section 2D.06 Size of Lettering (Link)

Additional Resources – Freeway and Expressway Guide Signing

MUTCD Section 2E.14 Size and Style of Letters and Signs (Link)
MUTCD Table 2E-2 Minimum Letter Heights and Numeral Sizes for Expressway Guide Signs According to Interchange Classification (Link)
MUTCD Table 2E-3 Minimum Letter Heights and Numeral Sizes for Expressway Guide Signs According to Type (Link)
MUTCD Table 2E-4 Minimum Letter Heights and Numeral Sizes for Freeway Guide Signs According to Interchange Classification (Link)
MUTCD Table 2E-5 Minimum Letter Heights and Numeral Sizes for Freeway Guide Signs According to Type (Link)

Corner Radius and Border Dimensions

Corner radii are generally determined by the shortest dimension of a sign size. Refer to design guidelines in SHS (Link).

Sign border thickness and inset are determined by the letter height of the major copy.   Light backgrounds (white, orange and yellow) require the border to be inset.

Shield Sizes

Shield height is determined by letter size on guide signs and type of road on route marker assemblies. Width is determined by route number (1-, 2- or 3-digit, with the exception of NC).  NC shields are diamond shaped.  The following table shows the shield size and the cardinal direction text size with the corresponding sign location and major copy letter heights.


LocationMajor Copy Letter HeightUS and InterstateNCCardinal Direction
1- and 2-Digit 3-Digit All
Ground MountedMilemarker12"x12"15"x12"12"x12"6.6"/6"B
Ground Mounted8"24" X 24"30" X 24"24" X 24"8"/6"E
Ground Mounted10.67" or 13.33"24" X 24"30" X 24"24" X 24"10"/8"E
Ground Mounted16"36" X 36"45" X 36"36" X 36"15"/12" E
Ground Mounted20"48" X 48"60" X 48"48" X 48"18"/15" E


(40mph or less)

10.67" or 13.33"24" X 24"30" X 24"36" X 36"10"/8"E


(45mph or more)

13.33"36" X 36"45" X 36"36" X 36"12"/10"E
Overhead16"36" X 36"45" X 36"36" X 36"15"/12" E
Overhead20"48" X 48"60" X 48"48" X 48"18"/15" E


The following table shows the shield size, auxiliary plaque size and arrow size for Type F Route Marker Assemblies.

LocationUS and InterstateNCAuxiliary PlaquesArrows/JCT
1- and 2-Digit 3-Digit All
-Y- Line
24" X 24"30" X 24"24" X 24"24" X 12"21" X 15"
Freeway or Expressway​
36" X 36"45" X 36"36" X 36"36" X 18"30" X 21"


Retroreflective Sign Sheeting

In North Carolina all non-black elements of roadway signs are required to be retroreflective.  NCDOT has three grades of retroreflective sheeting for various intents and purposes.  The signing plans shall state the required NCDOT Grade of Retroreflective Sheeting for each sign.

For signs with panel designs, the sheeting grade for the legend, arrows, shields, background and thickness shall be stated in the notes section of that panel design.  See Table 901-1 and 901-2 (Link) for appropriate aluminum thickness. For Type E and F signs the sheeting grade shall be stated in the General Notes on the title sheet.  For Type E signs requiring Yellow-Green fluorescent sheeting, the note shall appear on the Regulatory and Warning Sign Design sheets.

Additional Resource

TEPPL Policy S-68: Standard Practice for Retroreflective Sign Sheeting (Link)

Sign Design Order

Signs with custom panel designs should be shown four to a sheet, in numerical/alphabetical order.  On Type E Sign, Type F Sign and Milemarker sheets - the numbers should increase top to bottom and then from left to right.  Milemarker sheets should be ordered from lowest mile posting to highest, from top to bottom and then from left to right.

Additional Resources​

NCDOT GuideSign Updates (Link)

MUTCD Standard Highway Signs (SHS) (Link)

4.8 Sign Designs, GeneralSDU-04-08Approved

Legend Design

In urban areas where there is a combination of a street name and a destination on the guide sign, the street name shall be above the destination on the sign.

Arrows on Overhead Signs

Type A Arrows on overhead exit direction signs are placed to the right or left of the sign message (depending on direction of the exit) and centered vertically on the sign.  Type C arrows (downward pointing) are lane assignment arrows and shall be used for overhead guide signs to prescribe the use of specific lanes.  Lane control plaques may be used on non-freeway overhead signs to provide additional guidance to the user. (See MUTCD Section 2D.33)

Arrows on Ground Mounted Signs

Type A Arrows on ground mounted exit direction signs should be centered horizontally under the message.

Support spacing

If the proposed support spacing is not standard for the given panel width, the proposed support spacing shall be added to the panel design note as well as on the design panel (centerlines with spacing).  For proposed signs erected on existing supports, the existing support spacing shall be added to the panel design.

EXIT ONLY panels

Exit only panels shall be designed per MUTCD SHS E11-1 Series signs as shown in the 2012 Supplement.  Add the following note to the panel design notes, updating sizes as necessary:

“Bottom panel shall be yellow Grade C sheeting.  Legend shall be direct applied black non-reflective sheeting.  Arrow shall be black non-reflective sheeting on 0.032" aluminum and demountable.  Yellow panel is XXX" X 36". (Border Type = Recessed, Recess = 0.5", Width = 1.5", Radii = 12")

Attachment Method and Mounting Method

Secondary and supplemental signs are either attached to the primary sign by additional “Z" bars or connected directly to the supports. For all secondary and supplemental sign designs, add a note specifying the attachment or mounting method as shown on the support chart. (Link to Standard Drawings)

Aluminum Thickness see (Table 901-2) (include for all signs, milemarkers, overlays, etc..)

Additional Resource

Type A Overhead Panel Design Example (Link)

Type B Overhead Panel Design Example (Link)
Example Type D Panel Design

Applicable Standard Specifications


Applicable Standards

901.10 TYPE 'A' SIGNS
901.20 TYPE 'B' SIGNS

4.9 Type A and B Sign Panel DesignsSDU-04-09Approved
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