Pavement marking balloon symbol callouts identify the pavement marking material, color, width, pattern and thickness of pavement marking lines, symbols and alphanumeric characters. Standard pavement marking balloon symbol callouts are found in the Pavement Marking Symbols table on the SDU website.
All pavement marking lines shall be labeled with a balloon symbol callout using the standard two letter symbol shown in the NCDOT Pavement Marking Symbols table. Each line shall be labeled at least once per plan sheet; twice if the line extends more than half the plan sheet with one balloon symbol callout on each end of the sheet.
A single callout may point to multiple pavement markings.
Each unique pavement marking symbol shall either be labeled once per plan sheet or a table of the symbols shown on that plan sheet shall be provided.
If a proposed pavement marking does not have a standard callout symbol, use letter/letter or letter number combination that is not already a standard symbol but uses the same beginning letter as other symbols of the same material type. For example, use T18 for a proposed non-standard thermoplastic pavement marking.
Balloon symbol callouts CAD shall be active within the individual Pavement Marking Plan Sheets CAD files.
Pavement Marking Symbols – Revised 01/03/18 (Link)
Example Pavement Marking Plan Sheet (Link)