Increasing traffic congestion in major metropolitan areas is costing billions of dollars each year in lost productivity, wasted fuel, increasing air pollution and hours of delay. Adding new general purpose lanes is increasingly difficult because of factors such as construction costs, limited right-of-way, and environmental and societal concerns, so agencies are looking for solutions to improve the flow of traffic on existing facilities. One such solution is the concept of “managed lanes.” Through managed lanes, a variety of management tools and techniques (including include pricing, vehicle eligibility, and access control) are employed to improve freeway efficiency and to achieve optimal travel conditions. Examples of managed lanes include High-Occupancy Vehicle (HOV) lanes, value-priced lanes (such as High-Occupancy Toll, or HOT lanes), and exclusive or special use lanes (such as express, bus-only, or truck-only lanes).
This study reviews the state of the practice and the state of the art in managed lanes in order to increase understanding of (1) what managed lanes are (2) how to plan for implementation (3) what operational and design issues should be considered, and (4) how active management of the lanes over the life of the facility affect its implementation. This study uses a case study approach, highlighting best practices and lessons learned from four managed lanes projects, including:
- State Route 91, California
- Interstate 15, San Diego
- I-10 and US 290, Houston (also known as the QuickRide program)
- New Jersey Turnpike
For the purposes of this study, the research team focused on state of the art facilities that utilize pricing, but also employ a combination of other basic managed lane operational strategies (i.e. vehicle eligibility and access control).
State departments of transportation have employed a variety of lane management strategies in an effort to reduce congestion in urban areas. Two of the most common approaches include restricted use based on vehicle eligibility and control of access through limited ingress/egress express lanes and ramp metering. Examples include HOV lanes and exclusive use or special use lanes. More recently, value pricing has been introduced as an operational strategy to regulate demand. Value pricing includes charging motorists a toll for travel during the most congested times, or offering a discount for traveling in the off-peak. Examples include HOT lanes (these give HOV access to vehicles that do not meet occupancy requirements by assessing a toll on those vehicles) and variable toll lanes.
The analysis and selection of appropriate lane management strategies is critical to the success of the project. A variety of factors must be considered when determining lane management strategies, including: the objectives of the project, the opportunities available to the agency, and the characteristics and design elements of the facility. Based on the experiences in California, Texas and New Jersey, the following set of lessons learned for the selection of management strategies is presented.
- Clearly articulate project objectives. Managed lanes projects should have specific objectives, based on the characteristics of the corridor and the desires of the community. At the outset, the objectives of the project must be clearly articulated, as they form the basis for selecting the most appropriate lane management strategy and they serve to guide implementation of the project. In addition, a project may have multiple objectives -- such as increasing person movement and revenue generation – that need to be reconciled.
- The objective for the I-15 Express lanes was to make better use of available capacity in the existing HOV lane and to generate revenue in order to fund transit and HOV improvements. Using a dynamic pricing strategy, single occupancy vehicles (SOVs) were charged for access to the HOV lanes, with toll rates generally ranging from $.50 to $4.00, depending on the level of congestion (though they could be as high as $8 during severe congestion). This resulted in more efficient use of the HOV lane and generated revenue that was used to fund a new transit service. However, since encouraging HOV use was a priority for this project, SANDAG did not charge HOVs for their use of the facility. SANDAG had multiple objectives, and was willing to sacrifice a portion of its potential revenue stream in order to encourage HOV use.
- Similar to the I-15 project, the QuickRide program in Houston sought to make use of excess capacity in the HOV lane. Originally, 1-10 was built as an HOV lane, and a 3+ restriction was instituted. This resulted in under-use of the facility, but easing the restriction to allow HOV2s in the HOV lane caused traffic congestion. To address these issues, a lane management strategy involving pricing was adopted; HOV2s could use the HOV lane when the 3+ restriction was in place (during peak periods), but they would be charged a toll.
- For the New Jersey Turnpike project, the goal was to shift traffic demand out of the peak periods. Customers using E-Z Pass electronic toll collection traveling on the off-peak hours receive a 20 percent discount off the toll rate charged on the turnpike.
- Take advantage of opportunities. In the case studies, the agencies were able to take advantage of existing opportunities to move their project forward and to select the most efficient lane management strategy.
- For the SR91 project, federal and state funding was not available for the planned implementation of HOV lanes. The signing of a law that encouraged public-partnerships gave impetus to a new funding opportunity, whereby the California Department of Transportation (Caltrans) partnered with California Private Transportation Company (CPTC) to plan, finance, build and maintain four express lanes within SR91. The company negotiated a 35-year lease with the state after which ownership reverted back to the state. Pricing, as an operational strategy, provided the revenue generation necessary to move the project forward.
- For the QuickRide Program and the I-15 Express lanes project, the agencies took advantage of underutilized capacity on the HOV lanes and changed their operational strategies on the facility in order to maximize efficiency.
- Consider corridor characteristics and design elements. Before implementation, the agency needs to have a detailed understanding of the corridor characteristics as well as the design elements of the facility, as these elements will impact the selection of lane management strategies.
- The I-15 Express lanes and the QuickRide program were implemented on an existing facility (i.e. these projects included a conversion of HOV lanes to HOT lanes), so the design elements for both programs were already in place, and they were able to take advantage of existing technology in the corridor.
The selection of appropriate lane management strategies involves consideration of a number of key factors, including the objectives of the project, the opportunities available to the agency, and the corridor characteristics and design elements. A careful consideration of these factors will result in the selection of a lane management strategy that optimizes the use of available capacity on the facility, thus providing maximum mobility benefits to the users.
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