I-81 is one of the top eight truck routes in the U.S. In the state of Virginia, I-81 traverses 325.51 miles from Tennessee in the south to the West Virginia border in the north and passes through 12 counties. The highway was designed for a 15 percent truck volume, however trucks now account for somewhere between 20 to 40 percent of the total traffic volume. In 2001, the Virginia Department of Transportation (VDOT) developed a list of key improvements for I-81. The improvements include: developing the corridor as a multi-modal facility, incorporating a high degree of efficiency and safety for all users, which may include the physical separation of commercial and passenger vehicles; considering transit or other higher occupancy travel in and around growing urban areas, and using Intelligent Transportation Systems (ITSs) as short-, mid-, and long-term solutions to improving transportation flow and management (VDOT 2004). In 2003, a U.S. house transportation bill included $1.5 billion in federal funding for dedicated truck lanes. According to Representative Don Young (Alaska), author of the bill and a strong proponent of truck-only lanes; Separate lanes for trucks will move freight more efficiently and make our highways significantly safer.