Traffic heads west toward I-75 from Tibbs Road, enjoying green lights all the way
photo by Mitch Talley
If you’ve noticed your commute into and out of downtown Dalton by way of Walnut Ave, has been smoother in the past few weeks, it’s not just your imagination.
Behind the scenes, local and state traffic control engineers have been busy trying to coordinate the timing of the 16 traffic signal locations along the 5-mile-long lifeline from Martin Luther King Jr. Blvd. to I-75 so that motorists don’t have to stop as many times for red lights.
While that was easier said than done, the efforts of the Georgia Department of Transportation Traffic Operations project, totally funded by the state, are already paying measurable dividends.
“Most folks may be realizing their commute to work was smoother,” Dalton Assistant Public Works Director Andrew Parker says, “but by the time they get to work and they have other pressing things on their mind, they’ve already forgotten that, hey, traffic moved a little bit better when I came to work this morning.”
Such is the life for a traffic engineer.
While projects like new five-lane roads are easy for motorists to see, behind-the-scenes projects like a timing plan for traffic signals aren’t so visible.
The results are, though.
Mr. Parker says after the new timing coordination plan was implemented in late November, the average cumulative travel time for the entire route was sliced anywhere from 1 to 2.6 minutes, depending on the time of day, while the average increase in speed ranged from 3.3 to 7 miles per hour. The average number of stops at traffic signals along the corridor was reduced by as many as three times, too.
“Those numbers are one of the ways the traffic engineers and GDOT evaluate the success of the timing plans,” Mr. Parker said, “but I would argue that the results are even better than those figures indicate because I’ve traveled that corridor probably a hundred times since we’ve implemented the final plan, just to do ride-throughs, and I’ve been very, very pleased with the results. I know that our Public Works Director Benny Dunn lives on Dug Gap Road and drives to church in Murray County, and he said it’s just been a night and day difference for him.”
As any of the 25,000 to 30,000 commuters who travel along Walnut Ave. on an average day can attest, anything that helps make the trip easier is greatly appreciated.
The project actually started in early March with a kickoff meeting between GDOT, its traffic engineering consultant URS Corporation, and City of Dalton officials to discuss obvious issues with traffic on Walnut Ave.
A combination of sophisticated traffic counters using video cameras and the old familiar rubber tube counters placed in the road revealed that the west leg of Walnut Ave. had an average daily traffic count of 30,000 vehicles and the east leg had an average count of 25,000 vehicles a day.
Shortly afterwards, traffic engineers with URS began working to develop timing plans based on traffic patterns using sophisticated modeling software that evaluates a vehicle traveling through the entire corridor and attempts to develop coordinated signal timing plans for the most efficient travel.
It’s not as easy as just making traffic flow along Walnut Ave. Numerous side roads also need to be emptied onto Walnut Ave.
“It was very challenging,” Mr. Parker says. “It was tough to strike a balance between moving mainline traffic and avoiding long side street delays.”
He said URS workers quickly realized that Dalton is a very difficult city to perform traffic timing.
“Our consultants have projects all over the state, including Augusta, Savannah, Columbus, and Metro Atlanta,” Parker said, “but they say that Dalton is one of the most difficult based on variations in traffic patterns and truck traffic.”
Perhaps the biggest challenge to overcome was Walnut’s intersection at Dug Gap Road and Tibbs Road near Steak and Shake.
“Keep in mind that Tibbs Road has about 13,000 average daily traffic, which is very significant for a two-lane local road,” Mr. Parker said.
That intersection is in a constant state of flux, the engineers soon discovered.
“Some cycles on Tibbs Road, everybody would be wanting to turn left,” Mr. Parker said. “The next cycle they might all be wanting to go south to come to Dug Gap. Same thing for Dug Gap. We might have everybody wanting to turn left to go to West Walnut and the next cycle everybody might be wanting to go straight.”
That unpredictability eventually forced the engineers to break Dug Gap and Tibbs free from the coordinated timing plan.
“When we tried to run those two roads coordinated with the other signals on Walnut Ave., the length of the cycle needed to be so long that it was causing significant backups on other side streets and it was also causing a significant backup on Tibbs Road headed south that we’d never had before,” Mr. Parker said.
Leaving Dug Gap and Tibbs out of the coordinated timing plans means that eastbound motorists might hit green lights from I-75 until they make it to that intersection and then get stopped by a red light, Mr. Parker said. But then it might be smooth sailing all the way to MLK Jr. Blvd. after that.
“It’s not feasible to say that any timing plan solves all traffic issues,” Mr. Parker said, “so in other words, it’s not realistic to think that every single time you drive through the corridor, you’re never going to get stopped. The goal is to get stopped just once or twice, though.”
Mr. Parker says a fine-tuning period is underway now to make sure the new plan is working the best it can. Actually, the plan includes seven to 10 different variations depending on the time of day because traffic patterns constantly change over a 24-hour period.
Mr. Parker praised the state DOT for allowing Dalton to be the first city to experience the traffic control project under a new contract with URS. Actually, URS also helped fine-tune the signal timing along Cleveland Highway, though the City of Dalton had already made improvements in the timing on its own several months before so the improvements weren't as dramatic.
“I can’t say thanks enough to GDOT for allowing Dalton to have these two projects,” Mr. Parker said, “because again that’s zero local dollars that were expended to improve traffic flow on both corridors, and I would encourage the state to continue this program because it’s very important to local governments.”
Mr. Parker also thanked Roger Williams, a member of the Congressional District 14 Transportation Board, “because he has been very supportive in attempting to get some of these projects to Dalton that we haven’t gotten in the past.”
As part of the projects, the state also bought and installed GPS clocks at each of the 16 signal controller units along Walnut Avenue, an important purchase, according to Mr. Parker.
“These timing plans are built around time so every single control cabinet at each of the 16 signals has a controller, which is a fancy name for a computer that helps run that traffic signal. But if those times don’t match up at each controller, then that causes the coordination plan to get off. So, say you've got the traffic controller at Kroger saying 9:45 and the controller at Market Street saying 9:48, then that will kill your timing plan.”
In the past, the city has sent out technicians twice a week to manually correct the times at each of the 16 locations, “which is cost prohibitive and keeps these workers from doing other things they need to do,” Mr. Parker said.
“The fact that GDOT was willing to supply this GPS technology (at a cost of $500 per clock) has been a big win for our community,” he said.
Mr. Parker said the project will be an ongoing one since the state will pay the consultants for five years to perform quarterly assessments on the timing.
“So if, say, a new business is built three years from now that causes a total change in the traffic patterns, URS will come back in to revise the plan,” Mr. Parker said. “And that’s all part of the state contract so it won’t cost Dalton anything.”
Since the ultimate goal is to make using the roads easier for motorists, Mr. Parker encourages local residents to call his office with any issues they might see along Walnut Ave.
“We’ll be happy to take a look at it, evaluate it, and make adjustments if we deem them necessary,” he said, “because that’s how you ultimately get the best plan. Even as smart as the expensive modeling computers and as good as the software is that experts developed, the best timing plan comes after the process is done and we receive comments from the public and make adjustments based on that.”
If you would like to make a comment, call Mr. Parker’s office at 706-278-7077 and leave a message with the receptionist.
. (Photo by Mitch Talley).
This chart shows the improvements made during different times of the day after the new signal timing plan was implemented along Walnut Ave.
photo by Mitch Talley