significant impact on ITS costs and deployment schedules.

  • Privacy issues can present particular challenges in ITS projects, as new ITS technologies can often raise concerns about intrusive, “Big Brother”-type surveillance.

Construction of Exclusive Truck Lanes

The idea of exclusive truck lanes covers several types of designs and how each type can be used to better improve efficient use of the highways, reduce traffic congestion, improve safety for all highway vehicles, and reduce the cost of moving goods. Truck-only lanes allow for the possibility for future technologies such as ITS to be used to improve all of the aforementioned items. Construction of these lanes also offers the opportunity to upgrade the current highway designs for increased weight and traffic of the future. During the Missouri Department of Transportation study of Interstate-70 between Kansas City and St Louis, the supplemental environmental impact statement team chose the truck-only lanes strategy as the preferred alternative, instead of the widen existing I-70 strategy. With that selection, the next step was to apply the strategy across the corridor as alternatives. The study team assessed several alternatives before recommending a preferred one that, at a minimum, provides two truck-only lanes on the inside and two general-purpose lanes on the outside for both eastbound and westbound travelers.

From the perspective of traffic and engineering, the truck-only lanes strategy compared more favorably than the widen existing I-70 strategy in the key areas of freight efficiency, safety, constructability, and maintenance of traffic.

The design that is the most prominent uses two lanes in each direction for truck-only traffic. These lanes are placed on the inside of the current lanes of the federal highways such as interstate highways. The design fits best in the rural and country areas, so that the width of the road right-of-way does not become a problem.

In areas where that the road right-of-way does not allow for construction of the lanes on the same level plane, another design is considered as a possibility. This design places the truck lanes over the current auto traffic lanes. There is a third design that employs underground tunnels for getting past the problem of clearance or the lack of property for the extra lanes. Several studies have been done in the United States by state transportation departments, but to date no lanes have been built for the purpose of moving only truck traffic for any long distances. Figures 7-3 to 7-5 show the various designs that have been considered.

The provision of access points to/from the truck-only lanes depends on the nature of the corridor. For corridors serving long-haul/through trips, access points can be limited to key interchanges and staging areas (if long combination vehicles [LCVs] are permitted to operate). On the other hand, in urban corridors, where most trips are a relatively short distance, more access points would be required. In this case, the cost and financial analyses should consider the tradeoffs among capital costs, usage/toll revenues, and safety. The use of tolls to offset some of the costs to build and maintain these truck-only lanes must be cost effective for the vehicle owners, or they will be bypassed by drivers.

The California State Route 60 and Interstate 710 corridor studies demonstrated the importance of providing frequent access points to increase truck traffic demands in urban truck-only toll corridors that serve primarily short-haul trips. In the State Route 60 study, the tradeoff between limiting access points and generating high demand was a major issue, especially because high demand is desired to maximize possible toll revenues. Yet adding access points increases the capital costs for the corridor.

For LCVs to be effective, staging areas are needed to make up and break up the trailer combinations. The cost of these staging areas might be borne by the owner/operator of the toll facility or by the private sector. In Oregon, staging facilities are privately owned.

Advantages

The major advantage to truck-only lanes is that freight can move faster and more efficiently along these corridors. Longer and heavier loads on highways built for the extra loads and length would make the movement of goods more efficient. In addition, it is expected that congestion should be reduced by separating truck traffic from small-vehicle traffic. With proper planning for cross-lane traffic and intersections, along with access and egress, car and truck accidents will be

FIGURE 7-3 Example of truck-only lanes. SOURCE: FHWA (2005).

FIGURE 7-3 Example of truck-only lanes. SOURCE: FHWA (2005).



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