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CHAPTER 2 Background and Key Concepts This chapter provides a summary of key background concepts and issues that are important to the understanding of potential applications of CMV-only lanes. It summarizes a detailed dis- cussion of these issues that was included in this project's interim report and is contained in this report as Appendix A (available on the TRB website at by searching for NCHRP Report 649/NCFRP Report 3). The main topics that are discussed in this chapter include the following: Planning process issues, Configuration and design issues, Integration with ITS, LCV operations, and Tolling and privatization. 2.1 Planning Process Issues CMV-only lanes should be integrated with long-range planning objectives of a state or MPO, and they should be applied to selected corridors after a thorough evaluation of a number of differ- ent alternative approaches to achieve the same objectives. Some of the benefits that are sought from CMV-only lanes include those presented in Table 2.1. This table also indicates why CMV-only lanes might be a superior approach to achieving these benefits in certain circumstances. Since many applications of CMV-only lanes anticipate tolling as a way to finance the facility, Table 2.2 illustrates how some of the benefits described in Table 2.1 can create value for the private sector that can be captured by the public sector through tolling. A number of studies cited in Appendix A illustrate how inclusion of CMV-only lanes in long- range plans or how evaluation of CMV-only lanes as options in major corridor studies can be related to regional or corridor-specific planning goals. Specific regional goals that may be sup- ported by CMV-only lane concepts include: safety, improved mobility for both trucks and autos, economic development, and reduced neighborhood impacts (moving trucks to a desig- nated facility with clear mobility benefits). In determining the degree to which CMV-only lanes represent a feasible approach to supporting these objectives, the Georgia Department of Trans- portation (GDOT) notes, "to achieve the highest and best use of a truck-only lane system invest- ment requires an understanding of the market for truck-only lanes and designing a system that captures the greatest market share and provides the greatest opportunity to garner travel time savings."2 2 Georgia Department of Transportation, Truck-Only Lanes Needs Analysis and Engineering Assessment, April 2008. 5

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6 Separation of Vehicles--CMV-Only Lanes Table 2.1. Potential benefits of CMV-only lanes. Category Benefit Group Benefiting Description Operational Higher Travel Speeds General Purpose Vehicle separation allows all Efficiency (GP)2 Lane Users vehicles to travel at their designated Less Delay speeds without conflict. Slower CMV-Only Lane commercial vehicles are not present Improved Level of Users Service (LOS)1 in right (slow) travel lanes. Less weaving. Improved operational efficiency. Safety Enhanced Safety General Purpose Fewer, less severe crashes as a Lane Users result of vehicle separation (and minimal car-truck interaction). CMV-Only Lane Users Economic Enhanced Travel CMV-Only Lane Increased trip reliability and Options Users reduced transportation costs of fuel consumption due to severe congestion or delay caused by truck- car accidents. Improved Freight CMV-Only Lane The productivity of freight Productivity Users movement in and around major metropolitan areas and along long- haul intercity corridors is an important factor in ensuring local, regional, and national economic competitiveness. Environmental Reduced Vehicle General Purpose Stop-and-go traffic conditions Emissions Lane Users improve as congestion is decreased on general purpose lanes, and air CMV-Only Lane pollution emissions from slowed or Users stalled cars and trucks will be reduced. Notes: 1. LOS is a designation used to assess the state of performance of transportation systems. Usually, LOS categories are defined by the letters A, B, C, D, E, and F; wherein A stands for the best state of performance of the system while F stands for the worst. LOS categories are typically defined based on the performance objectives of a system, such as mobility (in which case, level of congestion measured in terms of volume-capacity (V/C) ratio, for example, is used to define LOS categories), or safety. 2. The mixed-flow lanes (lanes carrying both auto and truck traffic) of a highway are also referred to as general purpose (GP) lanes. Table 2.2. Additional CMV-only application benefits through tolling. Category Benefit Group Benefiting Description Operational Congestion General Purpose By imposing fees when demand levels Efficiency Management Lane Users reach capacity on CMV facilities, the level of congestion on CMV facilities is CMV-Only Lane controlled. Users Economic Revenue General Purpose Fees can provide an additional source of Lane Users revenue to pay for transportation improvements, especially the operations CMV-Only Lane and maintenance of the CMV lanes Users themselves. Note: Benefits are general, and are not specifically tied to either mandatory or optional tolling scenarios.

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Background and Key Concepts 7 Because of the high level of investment required for CMV-only lane projects, several studies have recommended "thresholds" be in place prior to pursuit of the project to be used in screening high potential corridors. These threshold categories are reasonable when considering that CMV-only lanes are most attractive when they provide meaningful blocks of travel time savings to commer- cial vehicle users, thus minimum values for numbers of trucks or percent trucks on roadway seg- ments can serve as a guide for planning. However, the conditions in the field necessary to ensure a successful CMV-only lane project can be difficult to quantify. By providing thresholds, planners are able to gauge, at a high level, whether the region's conditions warrant the concept. Research3 shows that a variety of CMV-only lane planning thresholds have been developed as follows: Mainline Volume Peak hour > 1,800 vehicles per hour per lane (vphpl) (Janson) Off-peak hour > 1,200 vphpl (Janson) Two-way average daily traffic (ADT) > 120,000 (Douglas) ADT > 100,000 (Battelle) Heavy Truck ADT > 20,000 for 10 mi (Douglas) Heavy Vehicle Mix > 30% (Janson) 25% Trucks (Battelle) Freight Generator Proximity Truck generator at one terminus (Douglas) Development of performance measures and screening criteria for CMV-only lane projects will aid agencies in ensuring that objectives set early in the planning process are met. Some examples of categories of performance measures that have been used in the studies cited in Appendix A include the following: Level of service on CMV-only lanes; Level of service or vehicle throughput throughout the corridor (including the multipurpose lanes); Safety through reduced number of total crashes but, more particularly, reduced number of fatal or injury crashes; Cost-effectiveness; Compatibility with local economic development plans (typically measured in terms of improved accessibility to major freight generators); and Reduced emissions due to smoother traffic flows. When evaluating CMV-only lanes as part of long-range plans or corridor studies, it is impor- tant to compare CMV-only lanes with other alternatives that can achieve the same objectives. The following appropriate alternatives that have been looked at in several of the studies described in Appendix A include: Equivalent capacity in multipurpose lanes, CMV-lanes with and without LCV operations and/or tolling, High-occupancy vehicle/high-occupancy toll (HOV/HOT) lanes or other types of special purpose lanes, and Increased rail capacity. In many of the studies of CMV-only lanes that were identified in this project, traditional travel demand models have been used as the primary tool for evaluation. As follows, these models have 3 Paul W. Dorothy, The Potential for Exclusive Truck Facilities in Ohio, presentation at Ohio Transportation Engineering Conference, 2007, Session7/OTEC%202007%20Truck%20Lane%20(Dorothy).pdf.

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8 Separation of Vehicles--CMV-Only Lanes some major shortcomings that planners should be aware of when they are using travel demand models to evaluate CMV-only lanes: Many state and regional travel demand models do not provide comprehensive coverage of truck activity by corridor with any breakdown by the different markets that trucks serve. This can be a critical shortcoming, especially if tolling is being evaluated. Some studies suggest that value of time for trucks may vary by commodity hauled or purpose of the trip. Another short- coming of many state and regional travel demand models is that they do not have accurate representation of truck origin-destination patterns, and this can make it difficult to estimate the level of CMV-only lane usage when the facility has limited access/egress locations as com- pared to existing mixed-flow facilities. The operational benefits of separating trucks and autos are not captured in traditional travel demand models, thus the travel time savings may not be accurately reflected in the analysis. Traditional travel demand models do not take into account the reliability benefits of CMV- only lanes. Likewise, they do not provide much information that can be used to evaluate safety benefits. Some of these shortcomings suggest that in the future, simulation models may be a more useful tool for evaluating the benefits of CMV-only lanes. Prior to undertaking a CMV-only lane project, it is important to understand the economic benefits to the community at large of having more effi- cient freight transportation. It also is important to be able to describe how CMV-only lanes will mitigate impacts of truck traffic as compared to other alternatives that may be seen as having more direct benefits to passenger vehicles. Since long-haul multistate corridors are often candidates for CMV-only lanes, it is important to establish effective planning and funding mechanisms for multistate collaboration. Several of the studies undertaken to date have established pooled funds study efforts that join states in a collaborative planning process, but few have taken the next step into coordinated multistate implementation of a CMV-only lane project. A wide range of stakeholders should be engaged in planning for CMV-only lanes, and each may have varied positions. Since CMV-only lanes are targeted at a relatively small portion of the motor-vehicle population, getting public support is critical. Since the implementation of CMV- only lanes has a direct impact on travel conditions for autos on general purpose lanes (due to the diversion of trucks to truck-only lanes), public input and outreach would be critical in increasing awareness of the impacts of truck-only lanes (and in many cases, for garnering public support for the implementation of truck-only lanes). Also, public outreach could be essential in understand- ing public perceptions regarding truck-only lanes, such as the impacts of concentrated truck traffic (traveling on CMV-only lanes) on surrounding neighborhoods, such as on access routes serving CMV-only lanes. As the primary users of CMV-only lanes, the involvement and acceptance of the trucking industry is critically important. The participation of the trucking industry would be crucial in understanding industry perceptions of, and expectations for, CMV-only lanes. For example, the work conducted by Reich et al.4 in Florida suggested that motor carriers would be amenable to the CMV-only lane concept if CMV-only lanes provide sufficient access to trucks, serve truckers' desired length of travel, and allow higher speed operations. The work conducted by Samuel et al.5 from the Reason Foundation talks about the importance of involving shippers and carriers, through the development of shipper/carrier forums, in contributing to policy development 4Stephen Reich, Janet Davis, Martin Catala, Anthony Ferraro, and Sisinnio Concas, The Potential for Reserved Truck Lanes and Truckways in Florida, Center for Urban Transportation Research, Research Report 21-17- 422-LO, May 2002. 5Peter Samuel, Robert W. Poole, Jr., and Jose Holguin Veras, Policy Study 294, Toll Truckways: A New Path Toward Safer and More Efficient Freight Transportation, Reason Foundation, June 2002.