Vehicle Preferences

System operators may restrict or encourage certain vehicles. Operators may restrict lanes to trucks only, buses only, long-length vehicles (trucks and buses), passenger vehicles only, or high-occupancy vehicles (HOV's). When applied to priced lanes, several operators have established high-occupancy toll lanes, to allow high occupancy vehicles (HOV's) to utilize assigned lanes to maximize person throughput.

Preferences can be established based on policy, economic, or operational bases. For example, in keeping with a region-wide "green Transportation heirarchy" system of preferences (favoring walking and bicycling, transit, freight, and high-occupancy passenger vehicles and single-occupancy passenger vehicles, in that order), a managed lane preference may be established for transit and freight. Likewise, a truck-only managed lane may be established to keep trucks off of arterial streets. In such cases, performance and planning measures for providing these managed lanes is with reference only to the service for those vehicle classes, not to improve passenger vehicle service.

When crafting a managed lanes policy solution through vehicle preferences, it is important to assure that the regulation has the desired affect. For example, high-occupancy vehicle lanes may draw family travel, rather than commuters sharing a ride. Thus, one solution adopted by SR 91 express lanes in California is to only give preferences to registered carpools and vanpools. Such narrow focus allows the policies to differentiate between high-priority policy goals of encouraging carpooling and low priority goals like getting families to the beach.

Vehicle preferences on managed lanes are often best implemented as part of systems. For example, a high-occupancy lane preference can be accompanied by queue by-pass facilities for ramp meters at on-ramps and/or by adjacent park and ride facilities. Truck facilities can be routed between inter-modal freight terminals with dedicated entrances and exits. Congestion pricing on managed lanes can be introduced with new high-speed bus service.

Typically, vehicle preferences alone are not sufficient to attain performance standards on facilities for passenger vehicles. Thus, in order to assure the managed lane achieves performance standards, HOV lanes are now usually implemented with a toll option – as a high-occupancy toll (HOT) lane.