Blog: City Blog

Maintaining City Streets through the Seasons

Weather that can’t make up its mind. Rain, ice, sleet, and snow. Salting components used to counter the winter weather. Rinse and repeat that cycle about ten times each winter.

It’s a rough life for a street. Add to that the millions of cars that pass over each year. Streets that receive a lot of truck traffic take an extra beating.

“This week may have experienced consistently low temperatures, but we’ve gone back and forth between the sixties and the teens over the last few weeks,” said Chad Weth, Director of Public Service. “For asphalt roads, that can be worse than places with colder climates because of the constant expanding and contracting.”

Age is another factor. Asphalt becomes brittle with age and the weight of passing traffic can start breaking it up. Surface cracks start to develop. These cracks provide an opportunity for water to penetrate the surface, leading to even bigger damage from freezing.

So, how are roads supposed to survive these conditions?

With more than 1,000 miles of roads to maintain, the City of Knoxville has an ongoing, mutlti-tiered plan to help keep Knoxville running smoothly.

POTHOLE PATCHING

Potholes typically form when asphalt expands and contracts due to temperature changes, allowing water to get under the sealed surface of the asphalt.

East Tennessee’s wavering winters often open the door for that process to happen. Just last year, in fact, City crews patched 480 potholes.

When the City receives a pothole complaint through its 311 call center, crews work to make the repair within 48 hours.

In ideal conditions, a permanent pothole patch can be applied. This means hot asphalt is placed on the pothole, pressed, and sealed.

However, when temperatures are below freezing, hot asphalt cools and cannot be applied, so City crews are required to make a “cold patch” using a dry mix. It’s essentially a rocky mix with an adhesive component mixed in.

These cold patches can be washed out relatively quickly, making the roads feel a bit rough in the later stretches of the winter season (until a more permanent fix can be made in warmer weather).

However, even in the deepest stretches of winter, Knoxville can have temperatures above freezing, allowing for permanent asphalt patches. Therefore, it’s always helpful to immediately report a pothole.

To report a pothole, please call 311.

RESURFACING SCHEDULE

“While pothole patching is a good tool to keep the road from deteriorating, the road is never truly restored until the resurfacing process happens,” said Jim Hagerman, Director of the Engineering Department.

“Pothole patching is comparable to a cavity filling for the tooth,” said Hagerman. “It prevents further damage, but once that enamel is compromised, there’s a likelihood that time and repetitive use will eventually catch up to it. Resurfacing the road is like giving a street its enamel back.”

The street resurfacing contract is one of the City’s largest ongoing capital projects, with $7.3 million dedicated toward the effort in the 2017/18 fiscal budget. KUB contributes a varying percentage of that funding each year to cover repaving expenses after utility work. City Engineers work to resurface 48 miles each year.

Street Resurfacing

Due to temperature constraints, streets are typically resurfaced between March and November in East Tennessee.

Along with regular inspections, City engineers use road classifications to help determine the resurfacing schedule. The Metropolitan Planning Commission has defined City of Knoxville roads under three categories in its Major Road Plan:

Arterials
City's goal is to resurface these every 10 years
Examples: Central Street, Cherry Street, Sutherland Avenue, Moody Avenue

Major Collectors
City's goal is to resurface these every 15 years
Examples: Deane Hill Drive, Inskip Road, Kimberlin Heights Road, Chilhowee Drive

Minor Collectors
City's goal is to resurface these every 20 years
Examples: Island Home Avenue, Hill Avenue, Magazine Road, Sheffield Drive, Edgewood Avenue

Local Streets
City's goal is to resurface these every 20 years
Minor streets, essentially neighborhood roads

Click HERE to view a copy of the Knoxville-Knox County Major Road Plan and to see a list of the classification for every road in Knox County.

There were approximately 200 road resurfacing projects as part of the 2017 Resurfacing Project. Some resurfacing projects finished in 2017 included:

Baxter Avenue/Wray Street/Central Street
Bradshaw Garden Drive from Clinton Highway to Pleasant Ridge Road
Central Street from Churchwell Avenue to Woodland Avenue
Cumberland Avenue from Seventeenth Street to Henley Street
Davenport Road from Phillips Avenue to Moody Avenue
Forest Park Boulevard from Sutherland Avenue to Kingston Pike
Gallaher View Road from Middlebook Pike to Kingston Pike
Harriet Tubman Street from McCalla Avenue to Martin Luther King, Jr. Avenue
Wilson Road from Tillery Road to Gap Road
Young High Pike from Martin Mill Pike to Chapman Highway

Because of major utility work completed by the Knoxville Utilities Board, 2015 and 2016 were some of the most productive years in recent decades for street paving in Knoxville. There were 65.32 miles resurfaced in 2015 and 68.05 miles completed in 2016.

Click HERE to view a full list of the 2017 resurfacing projects.

It should be noted that the annual resurfacing miles total does not include state highways located within the city limits (such as Northshore Drive, Kingston Pike, Chapman Highway, Asheville Highway, or Western Avenue).

Posted by On 08 January, 2018 at 12:14 PM