Safety Evaluation for Connected and Autonomous Vehicles’ Exclusive Lanes considering Penetrate Ratios and Impact of Trucks Using Surrogate Safety Measures

Table 1

Summary of previous research studies for connected and autonomous vehicles with mixture  environment.

Study	Base model	Scenarios	Main results
[23]	A platooning model (similar with Wiedemann 99 for HDV)	1 exclusive lane	Exclusive lanes for CAV could provide up to 5.5 times the capacity of the conventional freeway when platoon size is 20, interplatoon spacing is 50 meters, and intraplatoon spacing is 1 meter
[24]	Cellular automata	1, 2 exclusive lanes and 3 exclusive rows for CAVs on 2 lanes. MPRs = 0, 10%, …, 90%	Exclusive lanes for CAV will greatly improve the traffic condition of the freeway on MPRs = 10%–80%
[25]	Cellular automata	0, 1, or 2 exclusive lanes. MPRs = 0, 10%, … , 90%	Setting CAV exclusive lanes at low MPRs deteriorates the performance of overall traffic flow throughput, particularly under a low-density level
[26]	Not available	1 exclusive lane with 3 strategies: forced-everywhere, forced-reserved, and optional-everywhere	Optional use of the exclusive lane without any limitation on the type of operation could improve congestion, increase 30% capacity for a four-lane freeway
[27]	IDM model for CAV, Wiedemann 99 for HDV	0 or 1 exclusive lane	Connected vehicles’ platooning on the exclusive lane outperformed all lane scenarios
[28]	Wiedemann 99 for HDV, IDM model for CAV	MPRs = 0, 25%, 50%, 75%, and 100% on a freeway	CAVs bring about compelling benefit to road safety as traffic conflicts significantly reduce even at low penetration rates
[29]	Mixture (IDM, Wiedemann and modified Bando)	MPRs = 30%, 40%, 60%, 80%, and 100% on an arterial with 9 signalized intersections	CAVs reduce segment crash risk significantly in terms of five surrogate measures of safety