The truck speed for commercial trucks is being lowered to 55 mph in Hamilton County, three state commissioners said at a press conference at the Development
Resource Center on Tuesday afternoon.
At the same time, the maximum speed for autos on the freeways here will be lowered to 65 mph from the present 70 mph maximum.
Transportation Commissioner Gerald Nicely said the reason for also reducing the car speed is "to lessen the difference between the rates at which the two types of vehicles will be traveling."
Officials said the move is aimed at lowering air pollution from trucks in Hamilton County.
But Mayor Bob Corker said he and County Mayor Claude Ramsey often receive complaints about trucks driving fast on the freeways. He said the change "will make for a more pleasant drive on our freeways."
Commissioner Nicely said new speed limit signs should be up by early summer.
Also taking part in the press conference were Environment and Conservation Commissioner Betsy Child and Safety Commissioner Fred Phillips.
Commissioner Nicely said a study commissioned by the Federal Highway Administration shows that reducing truck speed limits by 10 miles per hour can reduce the nitrogen oxide emission factor by approximately 18 percent or more per truck.
He said, "If we get reductions anywhere close to that level in Hamilton County it will be worth it."
TDOT officials said the request for the changes was made by Mayor Corker and County Mayor Ramsey "in order to reduce polluting vehicle emissions with the goal of bringing Chattanooga and Hamilton County back into federally required ozone attainment levels as mandated by the Early Action Compact." The Early Action Compact is an Environmental Protection Agency program based on early action by local and state governments to reduce emissions in advance of regulatory deadlines.
“After studying the issue we believe that lowering the speed limit for large trucks will make a difference in air quality for Hamilton County,” said Commissioner Nicely.
"We are grateful to Commissioner Nicely and TDOT for working with us so closely to lower truck speed limits in Hamilton County," said Mayor Corker. "This action not only makes the air cleaner for our citizens. It helps ensure that we meet all of the requirements of the federal Early Action Compact as well as to maintain our robust efforts to attract new good paying jobs to the city."
County Mayor Ramsey said, “We really believe this can make a difference in air quality. This is not just about official regulations; this is an important health issue. We appreciate the commitment we’ve received today from everyone involved in this effort.”
The action is supported by the Tennessee Department of Environment and Conservation which works throughout the state to regulate and improve air quality.
“Reducing truck speed limits is another way citizens and government officials at all levels are working together to ensure our air is healthy to breathe,” said Commissioner Child. "Studies show that lowering the speed from 65 to 55 mph will help reduce NOx emissions from trucks traveling through the region. Improving air quality takes every control measure available, and I want to commend Chattanooga’s local leadership for taking this step forward."
The Chattanooga/Hamilton County Air Pollution Control Bureau estimates that reducing truck speeds from 70 mph to 55 mph could have the same impact as eliminating all industrial NOx by 11% in Hamilton County on a daily basis. “The Pollution Control Bureau also estimates that the decrease in speed will add only approximately three minutes of travel time to a truck’s trip through Hamilton County,” Commissioner Nicely added.
The Tennessee Highway Patrol will be ready to help, according to the head of that department.
“One of the key components of road safety is travel at safe and reasonable speeds,” said Commissioner Phillips. “We have worked closely with TDOT through this decision making process and are in agreement that the speed limit change is beneficial. It is the responsibility of the Department of Safety, through the Tennessee Highway Patrol, to ensure the new speed limit and all other traffic control regulations are followed by motorists.”
Mayor Corker said the city staff is also planning to meet with local law enforcement agencies to discuss the implementation of the new lower speed limits in the coming weeks.
A total of 56.85 miles of interstate will be impacted by the speed limit changes in Hamilton County. A section of US27 that runs approximately 17 miles in length will also have lower speed limits posted.