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88 APPENDIX G Research Needs Statement A GUIDE TO SUCCESSFULLY CONVERTING SEVERELY DISTRESSED PAVED ROADS TO UNPAVED ROADS Previous work (NCHRP 46-12) that synthesized the state of the practice of converting paved roads to unpaved roads iden- tified a need for a guideline that highlights effective practices in the realm of: â¢ Objective methods for the identification of roads that are suitable candidates for conversion; â¢ Information on how to successfully convert a road; and â¢ Guidance for outreach, communication to the public, and visualization tools. To date limited information is available on roads that have been converted from paved to unpaved, and what information is available often comes in the form of newspaper articles and anecdotal accounts of road conversions. The purpose of the guide is to document proven, effective practices that can be used in road conversion projects. The document will serve as a formal and peer-reviewed information source that local road agencies can use when road conversions are being considered. The use of the guide and acceptance of the practice of con- verting from paved to unpaved surfaces (unpaving) will pro- vide a case for the acceptance of road conversions as another pavement management technique. Although low-volume roads are typically identified as hav- ing an annual average daily traffic (AADT) of less than 400, roads that are appropriate candidates for conversion will typi- cally have an AADT of less than 150. These road are often used to access homes, are used by agricultural and extraction industries, or serve to access recreational areas. The wide vari- ety of road users, traffic patterns, and vehicle types are factors that need to be considered in the decision to unpave a road. Other factors include road condition, safety, required mainte- nance, as well as a life-cycle cost comparisons of different options, such as continued maintenance of the deteriorating road, rehabilitating the paved road, or converting the road to an unpaved surface. By identifying candidate roads for conver- sion, local road agencies can more effectively manage dwin- dling budgets. Road conversions are currently being undertaken without supporting documents or knowledge and typically involve pul- verizing the deteriorating surface and mixing it with the under- lying base materials. Supplemental material may be added where required, and in some instances the mixed material is stabilized with an appropriate chemical treatment. The processed materials are then compacted and shaped. Some converted roads are treated with dust abatement products. Once the road has been converted, follow-up maintenance is required in the form of blading, reapplication of dust abate- ment products, and periodic regravelling. The extent of knowledge on this topic is limited, but the practice of converting roads to unpaved is becoming more and more common. This is occurring in a climate in which budgets for local road agencies are decreasing, and for some, pavement deterioration is accelerating because of heavy vehicles, which often exceed legal load limits. RESEARCH OBJECTIVE To develop a guide that can serve as a comprehensive infor- mation source on effective practices for converting severely distressed paved roads to acceptable unpaved surfaces. POTENTIAL BENEFITS The main benefit of this project will be the ready availability of a comprehensive guidance document on converting severely distressed paved roads to acceptable unpaved surfaces. No such document currently exists. The guide will aid in more effec- tive selection of candidate roads for conversion, more effective conversions, and more effective communication with the pub- lic on how and why a conversion is taking place. The guide will allow for appropriate management of road maintenance funds and will serve as the basis for road conversions being accepted as another pavement management tool. TASKS Task 1 â Develop an outline of the guideline Task 2 â Conduct a review of available information Task 3 â Conduct a survey and or interviews to capture information on effective practices Task 4 â Prepare the guideline Task 5 â Construct pilot test roads to illustrate implemen- tation of the recommended procedures ESTIMATE OF FUNDING AND RESEARCH PERIOD Estimated Budget for Tasks 1 through 4: $300,000 Estimated Project Duration: 2 years
Abbreviations and acronyms used without deï¬nitions in TRB publications: A4A Airlines for America AAAE American Association of Airport Executives AASHO American Association of State Highway Officials AASHTO American Association of State Highway and Transportation Officials ACIâNA Airports Council InternationalâNorth America ACRP Airport Cooperative Research Program ADA Americans with Disabilities Act APTA American Public Transportation Association ASCE American Society of Civil Engineers ASME American Society of Mechanical Engineers ASTM American Society for Testing and Materials ATA American Trucking Associations CTAA Community Transportation Association of America CTBSSP Commercial Truck and Bus Safety Synthesis Program DHS Department of Homeland Security DOE Department of Energy EPA Environmental Protection Agency FAA Federal Aviation Administration FAST Fixing Americaâs Surface Transportation Act (2015) FHWA Federal Highway Administration FMCSA Federal Motor Carrier Safety Administration FRA Federal Railroad Administration FTA Federal Transit Administration HMCRP Hazardous Materials Cooperative Research Program IEEE Institute of Electrical and Electronics Engineers ISTEA Intermodal Surface Transportation Efficiency Act of 1991 ITE Institute of Transportation Engineers MAP-21 Moving Ahead for Progress in the 21st Century Act (2012) NASA National Aeronautics and Space Administration NASAO National Association of State Aviation Officials NCFRP National Cooperative Freight Research Program NCHRP National Cooperative Highway Research Program NHTSA National Highway Traffic Safety Administration NTSB National Transportation Safety Board PHMSA Pipeline and Hazardous Materials Safety Administration RITA Research and Innovative Technology Administration SAE Society of Automotive Engineers SAFETEA-LU Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (2005) TCRP Transit Cooperative Research Program TDC Transit Development Corporation TEA-21 Transportation Equity Act for the 21st Century (1998) TRB Transportation Research Board TSA Transportation Security Administration U.S.DOT United States Department of Transportation
TRANSPORTATION RESEARCH BOARD 5 0 0 F ifth S tre e t, N W W a s h in g to n , D C 2 0 0 0 1 A D D R ESS SER VICE R EQ UESTED NO N-PRO FIT O RG . U.S. PO STAG E PA ID CO LUM BIA, M D PER M IT NO . 88 ISBN 978-0-309-27205-6 9 7 8 0 3 0 9 2 7 2 0 5 6 9 0 0 0 0 Converting Paved Roads to Unpaved NCHRP Synthesis 485 TRB