Exclusive Lanes for Trucks and Cars on Interstate Highways

Increases in heavy truck traffic on the nation’s highways in recent years have raised concerns about safety and capacity, particularly on the Interstate system. In response, a number of strategies for dealing with the effect of truck traffic on safety and capacity have been developed. One promising strategy is to provide separate lanes for trucks and cars on freeways or Interstates. However, since separate lane strategies have not been widely used, little is known about their economic and operational effects. An FHWA computer model, referred to as EVFS, was evaluated. The model determines the economic feasibility of separating trucks and other vehicles on freeway segments. Practices and experiences with exclusive facilities nationwide were examined. EVFS can analyze many alternatives for a variety of conditions. It is inexpensive and easy to use. However, EVFS does not differentiate between the lanes to which exclusions are applied (inside, middle, outside), and physical barriers are not treated explicitly. To demonstrate the application of the program, 10 lane separation strategies were evaluated for a 50.7-km (31.5-mi) segment of I-81 in Virginia. The results of the I-81 analysis indicate that user savings can be achieved if one or more lanes are designated for the exclusive use of trucks or cars.