The National Academies

NCHRP 03-73 [Final]

Separation of Vehicles - CMV Only Lanes

  Project Data
Funds: $150,000
Research Agency: Cambridge Systematics
Principal Investigator: Michael Fischer
Effective Date: 12/27/2007
Completion Date: 6/26/2009
Comments: Completed. Published as NCHRP Report 649/NCFRP Report 3.

Congestion on our nation's highways is a leading contributor to the rising number of accidents. The interaction between cars and commercial vehicles, namely large trucks, having significantly different sizes/configurations, weights and operating capabilities acts to exacerbate the problem. As pressure mounts to increase the legal size and weight restrictions for commercial motor vehicles (CMVs), coupled with an increase in the number of vehicles on the nation's highways, government is tasked with trying to manage a transportation system with severely limited resources. Although the issue of CMV-only lanes is raised from time to time, as a potential method for both easing congestion and reducing the number of accidents, little if any, real data exist to enlighten transportation officials as to the efficacy of such lanes.

The Federal Highway Administration has performed preliminary research and conducted modeling scenarios on lane separation for different classes of vehicles. Additionally, the New Jersey Turnpike Authority (NJTPA) has vast experience in the area of lane separation for different types of vehicles. During the latter part of the 20th Century, the NJTPA opened two lanes in each direction on the New Jersey Turnpike (NJTP) that are physically separated from other traffic and that are specifically dedicated to CMV traffic. Statistics from 1998 revealed this portion of highway had a 36 percent lower accident rate than the stretch of Turnpike which has lanes open to all traffic. Furthermore, evidence suggests that other countries around the globe have experimented with the concept of lane separation for different classes of vehicles.

In summation, the concept of CMV lanes for large vehicles that travel our nation's highways is not a new one, however, considering the lack of any previous research into the aforementioned topic there is a real need for an in-depth review of existing data in this area. An examination of the current applications (NJTPA experience) and others would provide valuable information that could be utilized by transportation officials in determining the future of highway planning in their respective areas.

The objectives of this research project are to (1) examine the various performance characteristics of a CMV-only lane application within a highway (e.g., reduced congestion, accident reduction, etc.); (2) examine relative items such as cost variables, aspects of reduced and/or increased pavement wear; (3) examine/explore modeling scenarios which have been completed by others; (4) examine/explore the benefits to Intelligent Transportation Systems (ITS) technologies that are being used by various states [i.e., Automated Vehicle Identification (AVI) readers, Driver-less Vehicle Systems (DVS), Electronic Traffic Control and Monitoring (ETCM) system as well as other systems]; (5) examine/review the feasibility of increased size and weight standards on CMV only lanes; (6) examine factors related to the success of truck-only lane projects; (7) examine the suitability of tolling and privatization; and (8) prepare a report of pertinent data and findings that includes economic implications, transportation performance, safety benefits, and other impacts associated with the application of CMV-only lanes.

The projected increase in traffic and specifically commercial vehicle traffic on the highways nationwide makes this study critically important for future highway design and planning. As highway engineers and transportation officials across the nation struggle to resolve traffic congestion, as well as other issues involving the movement of vehicles on our highways, it becomes vitally important that all avenues are explored.

The motoring public is clamoring for a transportation system that is responsive to its needs. Drivers across the nation have made it clear: they want a system that reduces congestion and reduces accidents. Moreover, they have expressed their displeasure of having to intermingle with large vehicles (namely trucks and buses) on the Interstate System and believe this to be a deadly combination that courts disaster.

The study would provide great incite into the most effective methods for accommodating a broad spectrum of commercial and noncommercial vehicles on our major highways.

Status:  Completed.  Published as NCHRP Report 649/NCFRP Report 3. As referenced in the report, appendices A through D are available here.

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