SPR Active Projects
|Access Management Best Practices Manual |
||Oregon State University|
|Start Date for ODOT:
|Completion Date for ODOT:
The transportation industry has been aware for several years that there are substantial safety and operational benefits when a transportation system is constructed or retrofitted with strategic access management designs such as shared driveways, raised medians, or driveway restrictions near intersections. In the Oregon Highway Plan, goal number three identifies access management as the single largest contributor to highway safety and essential to the efficiency protection of existing and planned state highways. The Transportation Research Board (TRB) holds a bi-annual meeting on access management and publishes a key document know as the Access Management Manual. This TRB document addresses access management principles, techniques, and basic design configurations. It also includes recommendations for state and local involvement, case examples of access management techniques, public information strategies, and legal considerations. Though this TRB document provides substantial information regarding the application of access management principles and strategies, it does not provide a means for decision makers to make data-driven decisions that can show performance measures or provide information to help these decision makers or designers quantify the expected benefits of potential candidate treatments. Access management has met with significant resistance from the business community as business owners often perceive access management treatments as a means for restricting access to businesses adjacent to the public road. It is important to develop a best practices document for the state of Oregon that includes decision-support tools that will help quantify the anticipated results and determine the costs and benefits of these choices to both the transportation agency as well as to the community.
The states of Florida and Colorado were early leaders in the areas of access management and both states developed access manual codes to enhance access management needs within their respective states. In addition, the state of Florida developed the Florida Median Handbook in 1997 and the Florida Driveway Handbook in 2005 to specifically address access management techniques for the state of Florida. These documents serve as design recommendations for median and driveway locations. In 2005, the state of Iowa released their Access Management Handbook and a companion Access Management Toolkit. The handbook addresses access management principles and the toolkit quantifies overall benefits of access management principles. In recent years, several access management researchers have made headway towards quantifying specific access management benefits, yet this information is not readily available and may not be applicable to all regions. For example, states where access management has been given substantial attention (Florida, Texas, Colorado, and Iowa for example) have unique issues (such as older drivers, unfamiliar drivers, frontage road systems) that do not completely capture conditions in the state of Oregon or other states.
The state of Oregon needs a comprehensive document that addresses the potential access management treatments and their associated performance measures. The document also needs to be compatible with Oregon regional mobility and safety objectives such as comprehensive bicycle lane configurations. Oregon is also in need of a method for tracking the benefits of these access management improvements so as to provide an empirical basis to aid in the decision making process. This proposed research will compile the best practices from the access management literature, will incorporate the recent research on benefits into a document usable for the state of Oregon, and will provide a resource for decision makers to determine the most effective and efficient use of access management funds.
This proposed research project will compile information currently available in many documents; however, the research team will critically scrutinize available, often conflicting, information to determine accuracy and applicability for the state of Oregon. The specific objectives of this proposed research are to develop measurable criteria to evaluate access management techniques and improvements, to survey practices in other states and their techniques in developing those practices, and to determine data collection practices necessary to properly measure outcomes.
The product of this research effort will be the creation of the Oregon Access Management Best Practices Manual. This resulting document can be used by engineers, decision makers, and educators to help the transportation community better understand the appropriate application of access management strategies and how to quantify the benefits of various access management options.
This Manual will help Oregon transportation agencies evaluate alternatives and select the access management techniques that best achieve system management goals. A reference manual that quantifies the impacts of using access management techniques will help these agencies make more informed system management decisions. For example, previous research determined that ‘a change from 10 to 20 driveways per mile would result in a 41% increase in accidents’. This kind of information will help representatives of transportation agencies explain the principles and benefits of access management to elected officials, local agency partners, and private developers. Quantifying the impacts access management has on system management will help develop credibility for the use of these access management techniques.
Oregon will use the Access Management Best Practices Manual in a variety of training classes. The research will be presented at regional, statewide and national land use and transportation conferences, such as the TRB Access Management Bi-annual conference, the annual Oregon Planning Institute, ACEC conferences and the Project Delivery Leadership Academy. The Manual will be made available throughout the Department and to consultants from the Access Management Program’s website. It would also be submitted for inclusion as a resource on the TRB website.
The Access Management Best Practices Manual will be used to help determine and apply the best management techniques to achieve state goals. The Manual will be used to evaluate alternatives and assess outcomes both for state and local transportation system planning and to assess and mitigate development impacts.
The Manual will be an educational tool to help governing jurisdictions communicate and market the principles and benefits of access management. It will help establish consistent statewide understanding, expectations, and application of access management techniques.
ACCESS MANAGEMENT BEST PRACTICES MANUAL WORK PLAN
|Mechanistic Pavement Design Instrumentation |
||Oregon State University|
|Start Date for ODOT:
|Completion Date for ODOT:
The principal objective of the research project is to obtain key information (i.e., engineering properties of the materials used for construction and in-service response of these materials to applied truck loads) that will be used to assess the validity of predicted tensile strain via layered elastic analysis, which is a key input into the fatigue cracking model of the new design procedure. More specifically, the objectives of the project are to:
1. Instrument three new HMA pavements that have differing structure (i.e., HMA thickness, base course thickness and type, and subgrade type), truck loading volume, and that are constructed in differing climatic conditions such that pavement response due to truck loading can be measured periodically throughout the year.
2. Conduct necessary field testing and obtain field samples for laboratory testing.
3. Conduct the necessary laboratory tests on the samples obtained from the test sites.
4. Collect data from the instrumented test sites on a frequent basis (e.g., at least once per month).
5. Use the data collected from the instrumented pavements (i.e., axle loads, axle configurations and/or truck classification, induced tensile strain, and pavement temperature) as well as information derived from laboratory tests conducted on the field samples to validate tensile strain prediction via layered elastic analysis for the range of pavement structures, truck traffic volumes, and climatic conditions investigated.
The project involves installing several instruments within and on top of three hot mix asphalt pavements during the construction process and periodically collecting data from the instruments. Analyses of the data will be used to validate a key component of the new pavement design procedure currently being implemented by the Oregon Department of Transportation (ODOT). In addition, loose hot mix asphalt and cores extracted shortly after construction will be obtained and tested in the laboratory for dynamic modulus, a key input in the new design procedure. Other field samples will be obtained and tested as necessary for analysis purposes. Falling weight deflectometer testing will be conducted on a seasonal basis to obtain layer moduli of the aggregate base course and subgrade soil. Predictions of tensile strain using layered elastic analysis will be generated and compared to the measured values. It is expected that the results of the study, in combination with the results of a current study, will provide sufficient evidence to determine the validity of tensile strain prediction using layered elastic analysis (as required in the new design procedure) for a range of pavement thickness, traffic loads, and climatic conditions.
The effort to move to mechanistic pavement design procedures does not end with the implementation of the new work procedures. There will be significant work to prepare for the implementation of the AASHTO design guide. A schedule for implementation of the new design guide cannot be made at this time. There is much work happening at the national level in addition to the work being conducted by the states.
The plan at this time is to tap into other states work and use this information to determine and prioritize the additional research required by ODOT. The implementation schedule for the AASHTO design guide is dependent upon completion of the current national research work, adoption by AASHTO and the ability of ODOT to continue research efforts in preparing for use of the AASHTO design guide.
MECHANISTIC PAVEMENT DESIGN INSTRUMENTATION WORK PLAN