Driving simulator study of a motorway car share lane: lessons for the design and implementation of novel schemes

The TRL car driving simulator (CarSim) has been used to evaluate several novel traffic management schemes, including, Active Traffic Management (ATM), segregated motorway, and most recently, a car share or High Occupancy Vehicle (HOV) lane. Car Share lanes are designated for vehicles with two or more occupants with the ambition of increasing passenger throughput by giving priority to vehicles with multiple occupants. CarSim was used to assess the design of a Car Share lane for use on the motorway. The project evaluated: the clarity of the signing and road markings; use and violations; impact on motorway exit behaviour and driver attitudes toward the scheme. Forty-eight participants drove the route either as a single occupancy vehicle or as a high occupancy vehicle. The virtual environment was a realistic representation of a proposed motorway Car Share lane scheme. Results indicated a high degree of comprehension and compliance with the scheme. However, the rules under emergency traffic management arrangements were less well understood. Together, the results of TRL trials on novel traffic schemes offer valuable insight into the best strategies for their design and implementation on UK motorways. Themes from each of the studies are drawn together to identify key lessons for best practice.