Due to their physical and operational characteristics, freight trucks can significantly of the operational and safety characteristics for non-truck drivers (1). Trucks, when involved in crashes with non-trucks, cause more fatalities and injuries to non-truck occupants. Truck crashes are usually more costly to everyone involved, including law enforcement, DOTs that are responsible for clean-up and repairs, costs of increased congestion, and ultimately the tax payers. With the increasing truck volumes on the nations roadways more and more states are trying to determine the feasibility of constructing exclusive truck facilities.
There are many factors to consider when determining if an exclusive truck facility is appropriate. Some considerations include: Is the project operationally necessary? Is the project economically feasible? Will this project increase the safety of the area? There are many reports and research that give guidance on determining the answers to these questions using measurable truck safety hazards on freeways. There are three main configurations to separate truck traffic from non-truck traffic. These include: 1) exclusive truck facilities that are completely separated by a physical barrier from non-truck lanes, 2) exclusive truck lanes that are not physically separated from non-truck traffic, and 3) restricting truck traffic from specific lanes causing the non-restricted lanes to carry all of the truck traffic. There are different variations of each of these configurations.
As of 1986, twenty six states used some variation of heavy vehicle lane restrictions. Although there is not conclusive research indicating that the lane restrictions have a positive impact on safety, surveys have shown that the public has a positive view of these restrictions. For this reason lane restrictions have continued to be used. (2) The idea of exclusive truck routes and exclusive truck lanes is not new. When the San Francisco - Oakland Bay Bridge was first opened in 1936 the top level consisted of six automobile lanes and the lower level provided three exclusive truck lanes and two train tracks. (3) Although exclusive truck lanes were present in the United States of America as early as 1936, this capacity management technique is not wide spread.
Presently there are no high speed long distance exclusive facilities or exclusive truck lanes operating the United States today, however, state of Texas has approved the construction of the Texas Trans Regional Corridor, a separated lane facility that will be intended for heavy truck use along I-35 (http://www.corridorwatch.org/ttc/cw-plan0206-02summary.htm.)