According to a 2016 Transportation Research Board report, due to reduced funding for maintenance and construction, safety issues or complaints, local road agencies are unpaving local roads with low traffic.
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,” wrote the National Cooperative Highway Research Program authors in the report’s summary.
There’s pros and cons, as 140 survey responses from 48 states and the experience of Montpelier, Vt., revealed.
In July, WIRED learned about the unintended consequences of the nation’s 1.6 million miles of gravel and dirt road. When cars get all dinged up, people start driving sport utility vehicles, a Montpelier car maintenance shop owner told the magazine. Then there’s the air quality and health risks of kicking up dust, dirt and pollutants that might be there, as the report noted.
But by unpaving local roads instead of maintaining pavement, Montpelier saved about $120,000, leaving more funds for urgent bridge and retaining wall repairs, the city’s head of public works reported. Based on the research, most local road agencies are finding the financial outcome of unpaving local roads favorable.
“The reported cost of converting ranged from $1,000 to $100,000 per road segment or mile,” depending on materials and requirements variables, the report said.
However, there are knowledge gaps when it comes to how agencies manage road conversion projects. There is no road conversions handbook or design guide.
“Local road agencies would benefit from direction in planning projects that will lead to the optimal use of available materials and equipment and a smooth, safe and maintainable driving surface upon completion,” wrote the researchers.
Of those surveyed, local road agencies rarely document these projects. At present, only cities and agencies in 27 states have documented where they are unpaving local roads.
How to Complete a Successful Road Conversion Project
The research defined the the following success factors when unpaving local roads:
- Sound engineering investigation and design
- Selection of quality granular surfacing materials
- Best practices in construction management
- Public outreach and education
The last one was important in Montpelier, as the car maintenance shop owner remarked that the community has nostalgia for the dirt roads and that it’s probably better for cars than roads strewn with potholes. The researchers concurred.
