NCDOT has installed many one-way U-turn crossovers on arterial roads in recent years. Usually, these crossovers are part of a reduced conflict intersection (RCI), median U-turn (MUT) intersection, or other alternative design. The NCDOT Roadway Design Manual calls for full control of access on U-turn bulbs' origin and terminal ends. Safety problems may occur when side streets (or driveways) and U-turn crossovers are located at the same location.
Though most of the U-turn crossovers NCDOT has constructed have included control of access on the bulb-out (terminal) side, and many have included control of access on the origin side; purchasing this control of access is expensive, and sometimes it means moving or closing an existing driveway or acquiring an entire property. With the price of real estate increasing quickly in the metro areas of NC, these purchases can add significantly to project costs, sometimes endangering the viability of projects or meaning that fewer other projects can be constructed.
In addition, it is difficult to make the public relations case for a project being good for business when it involves having to take properties, remove driveways, or move driveways that are not in the direct path of the construction. NCDOT's CLEAR (Communicate Lessons, Exchange Advice, Record) program has suggested examining the practice of including full control of access at U-turn crossovers.
A few examples of possible study sites in Michigan
This project aims to help NCDOT make optimum decisions on whether to provide / not provide control of access near U-turn crossovers. The objectives of this research are:
- To develop CMFs for U-turn crossovers with or without access control, and
- To develop a set of considerations to include in the Roadway Design Manual addressing this issue.
Having reliable CMFs and a subsequent set of considerations for U-turn crossovers with or without access control would allow NCDOT to make informed decisions on whether to provide access control near a U-turn crossover and where the cost of doing so is not justified.
