Road building and maintenance are expensive and Bradley County is dealing with both because it is one of the fastest growing counties in Tennessee, Road Superintendent Sandra Knight Collins told the Chattanooga Engineers Club on Monday.
The 2010 Bradley County population was 98,963. In 2015 the estimated population was 104,091. There are 338 square miles in Bradley County including 26 in the city of Cleveland with 749 miles of city roads and 1,284 miles of county roads. The county has 12 signalized intersections. Those in the city limits are taken care of by Cleveland.
Supt. Collins said the county road department has a budget of $7 million a year, 50 percent coming from property tax and state aid and approximately 50 percent from the gas tax. Funds for road work are dwindling, she said, because less gasoline is being used due to hybrid vehicles using less fuel and electric cars using none and because no one wants to raise property taxes. With the cost for repaving at approximately $100,000 per mile using county employees and equipment, projects have to be limited. “We are being forced to do more with less,” she said.
One idea that would increase tax coming from gas sales would be to base the gas tax on mileage. This would be a charge for using, since it is known that trucks travel more miles and do more damage to roads than do cars, she said.
There is also an escalating price of materials. In 1998 asphalt was $17.94 per ton and today it is over $95 along with rock and drainage tiles increasing in cost. For roads where traffic travels 45 mph or more “D-Mix” asphalt, that has granite mixed in, must be used, which costs an additional $13 per ton.
In 1998 multiple roads could be paved where today officials have to pick and choose which ones need it the most. To illustrate this, Supt. Collins said that the budget for paving is $2 million this year. In1998 the county would have been able to pave 100 miles with that money, but today that number is 30 miles. This puts the replacement of roads on a 25-year cycle.
State aid for Bradley County for 2016-2017 is $703,000. It can only be used for major collector roads, shoulder stone and striping. The state will pay 98 percent of the cost for these roads with the county’s match being two percent. Using county employees and equipment, repaving the Tunnel Hill Road, consisting of 7.29 miles, cost Bradley County $641,000, or approximately $100,000 per mile, the speaker said.
Bridge work is another component in the high cost of road up-keep. If the span of a bridge is over 20 feet, it must be inspected by the state, while below that, the county is responsible for inspections. In Bradley County there are 116 state-inspected bridges and 90 that the county must examine every two years, using the state formula. If a bridge is determined to have a capacity below 10 tons, it is put on the first list for repairs. If the limit is between 10 and 40, it is put on list two.
Bridge funding comes from the state at 98 percent with the county’s match of two percent, the same as paving. This year Bradley will receive $50,200 from Tennessee for bridges. Bradley County’s balance for bridges is $75,168. The cost of one bridge, the Baker Bridge Road, came to $630,986. The county had to move money from the paving fund into the bridge fund to pay the difference, but money cannot be moved in the other direction, said Ms. Collins.
Another option is to use prefabricated bridges that are put together at the location at the same time that other workers are preparing the site. When assembled, the bridge is lifted into place after which the road is paved. This process can be done in as little as one week at an approximate cost of $70,000. "We go this way, when possible," said the superintendent. As of now, however, the longest span that has been attempted is 18 feet, but the capabilities are improving, she said. A bridge on Lyles Road was replaced using this method. Because Bradley historically has been a rural county, bridges were built for heavy loads because they were used for cattle crossings. As it has become more urban, the weight ratings can be lowered because the use has changed.
Recent TDOT projects in Bradley County are the Exit 20 Industrial Access Road, with widened bridges and ramps. Another is the Local Interstate Connector South at Stonelake, where the new Spring Creek Industrial Park is and retail space will be located. On the other side of the road is the Local Interstate Connector North at Pleasant Grove, which will open up the whole area around it for development. Others include the new industrial interchange for Wacker, Spring Branch/South Industrial Park, Whirlpool SIA widening and upgrades and signalization at Exit 33.
Future projects are the APD 40 interchanges to access the industrial park development and widening and realignment of Highway 60/Georgetown Road.
During a question-answer time, Supt. Collins said that materials other than the high-priced asphalt are being used experimentally, but that she has not used it in case it fails, which would be a waste of taxpayer money. She said she would wait to use it once it has been proven. Materials that have been milled up from replacing old roads have also been experimented with by the state, she said, but at this point she has just watched.
When asked what causes problems with bridges, she said that scour, or sand and stone, is one thing that deteriorates around bridge piers, especially in places where flooding occurs. Also rust and decayed wood causes bridges to weaken. Some bridges are constructed by pouring concrete in different sections causing the road to settle differently and crack where water enters and cause more problems.