Converting Paved Roads to Unpaved

The survey conducted for this project identified 48 local, state, and federal agencies that have conducted road conversions and nine more that are considering this action. Almost 70 conversion projects were identified and a total of 550 miles of road converted to unpaved.  In seeking a cost-effective alternative to continued maintenance and repair of deteriorating pavement, agencies have begun to recognize that many roads with very low traffic volumes can be maintained more economically and at a higher level of service with an unpaved or granular surface.   Final Report available in documents below or through the TRB (National Academies of Sciences) website.

The purpose of this project is to prepare a synthesis that identifies measures to analyze and objectively determine when to convert a paved surface to an unpaved surface, and to identify appropriate unpaved road maintenance and management strategies that will cost-effectively maintain these converted pavements in a good condition.

In the past few years, the increased costs of construction and maintenance in combination with insufficient Federal, State, and local funding have resulted in a situation where asset managers are converting the pavements on aging rural roads to unpaved. In addition, failing to maintain a paved surface may lead to degradation in its ability to safely function as the surface becomes rough and slows down the average speed of traffic. With the costs of maintenance and rehabilitation of aging pavements increasing, continuously shrinking budgets, and increasing loads from agricultural, energy, and freight sectors, the practice of converting pavements to unpaved will continue to grow. These issues make it necessary to identify measures to analyze and objectively determine when to convert to an unpaved surface, and to identify appropriate unpaved road maintenance and management strategies that will cost-effectively keep these converted pavements in a better condition than the original distressed asphalt pavement. Information for the synthesis will be collected through a literature review, survey, and interviews.  The synthesis will also include case studies.