As indicated in the 2003 TRB Access Management Manual: “Roads are an important public resource. They are costly to build and to improve or replace. In a revenue-constrained environment, effective management of the transportation system is not an option—it is essential. It is simply not practical to allow major arterial roadways to deteriorate under the assumption that they will be replaced or reconstructed in the future. Yet many areas continue to do just that—by allowing closely spaced curb cuts, median openings across a turn lane, driveways in a major intersection, or poorly coordinated traffic signals—thus creating unsafe and congested conditions on major roadways.”
In the past, much of the research on the benefits of access management was related to operational and safety effects. There is limited information available to transportation agencies regarding the economic impacts of access management. Research typically focused on addressing the concerns of business owners that changes in access to their property—such as consolidating driveways or installing raised medians—will lead to fewer customers and reduced sales. Much of this research related to the economic effects focused on non-traversable medians. There has been little documentation of the costs related to poorly managing access.
This lack of information contributes to difficulties that agencies have in administering their access management programs. These difficulties may include an agency having to assume the cost for improvements not assigned to a developer to mitigate adverse effects of development-related traffic. These costs could range from providing a traffic signal, a right- or left-turn lane, or a median where none exists to making major modifications such as widening a highway or constructing a bypass or new interchange. In addition, there are liabilities to an agency, including those related to congestion and crashes, until mitigation can be implemented. There are also land use decisions, such as allowing subdivisions with each property having access to an arterial (e.g., “death by a thousand cuts”), which could have potential costs and liabilities involving public funding for improvements to maintain the same highway performance level. These all represent additional burdens that are especially problematic to agencies in a poor economic environment. This research will provide information and tools to assist agencies in making access management decisions, recognizing asset management implications such as managing assets to achieve the greatest return on the investment made in the transportation system.
The main objective of the research is to develop guidance for public agencies to use in making decisions regarding access management by helping them identify the benefits and costs of access management for maximizing the public’s investment in the highway system. This will help guide agency access-related decisions and assist in the formulation and justification of access management solutions that may offer the best outcome but may require additional time or cost up front, especially in an environment where there are insufficient funds for basic needs and operations. The research will also benefit agencies by providing information that would be used in achieving asset management objectives.
The research will involve identifying strategies used by agencies to be proactive in their access-related decisions to minimize their costs and liabilities. This will include agencies with a wide range of access management programs—from those having comprehensive programs to those that focus their efforts on administering driveway permits. Information will be compiled on cost savings and benefits related to liability considerations from applying their access management criteria.
Recognizing the potential difficulty in estimating costs savings, the research also will compile information to identify the costs and liabilities related to what happens when decisions are made that do not adequately consider access-related impacts. Traffic operations and safety information would be included. This information will be presented in the form of case studies. To the extent available, data will include costs related to right-of-way and traffic crashes. These case studies would be reported anonymously to encourage agencies to share their experience. This approach was successfully used in NCHRP Synthesis 404: State of the Practice in Highway Access Management to report on access management program barriers and difficulties.
Outreach will include state, regional, county, city, and local agencies that represent a wide range of access management and related programs and decision making processes. The research will identify the effects of decisions related to new development, redevelopment, and road improvement projects. To the extent available, the research will reflect information related to agency funding sources for managing access and liabilities emanating from poor access management practices.
Research is expected to include (1) developing the work program; (2) locating and assembling documented information as part of a literature search and review of available access management references; (3) identifying complementary research to identify any synergies with this effort; (4) surveying agencies to obtain information they have relating to economic effect and suggested candidates for case studies—sections of the survey could allow for anonymity (as was done for NCHRP Synthesis 404) to help encourage agencies to share their experiences; (5) compiling the information, including the development of the case studies that will demonstrate lessons learned and the costs/liabilities of access management decisions—case studies will include access management projects recently constructed in different environments (e.g., urban, rural, suburban); (6) identifying methods for agencies to apply in making informed, comprehensive access management decisions with consideration of the potential cost/liability of options that would not mitigate adverse effects (for example, the impact of development-related traffic that results in the need for intersection improvements, such as traffic signalization); and (7) identifying areas of future research needs.
The guidance should be useful by professionals at all levels of government to help them make access management decisions in a proactive manner. This research has the potential for a large benefit in terms of cost and sustainability, with a relatively small investment. This research would be useful to national level policymakers, state DOTs, metropolitan planning organizations, regional planning agencies, developers, and others interested in access management.
Note: The AASHTO Standing Committee on Research asked that aspects of Problem No. 2014-G-29 be considered as practical.