Athens working to solve downtown traffic congestionPosted: February 27, 2014
By Clay Reynolds
The UGA arch looks out over the T-shaped interchange of Broad Street and College Avenue – a crossroads that is one of downtown Athens’ most active traffic junctions and a role-player in frustration many drivers experience when it comes to traffic delays.
The intersection’s activity mainly comes from the vehicles on Broad. Yet the signal governing the intersection, which runs on a fixed timer, gives what little traffic is on College Avenue just as much green time.
Except at the busiest times of the day, it’s rare to see more than a few vehicles waiting at the light on College to turn left or right onto the main thoroughfare. The 60 seconds usually afforded to them late in the afternoon on a weekday is ample time for them to move through after the waiting pedestrians cross over.
So in most instances, half of the time in that cycle length goes to waste as drivers on Broad idle at the red light watching the opposite signal remains green for no one.
These situations, at peak traffic hours, often lead to congestion around the Broad-College intersection and others downtown. This causes some minor, albeit significant, delays for motorists and other travelers through the area.
The Athens-Clarke County Transportation and Public Works Department’s approach to remedying the problem entails a technology upgrade for many of these fixed-time traffic signals downtown. Drivers, according to ACC head traffic engineer Steve Decker, could see a “major difference” in the amount of traffic congestion downtown as a result of these improvements.
The strategy, termed “actuation,” involves the addition of pavement sensors, cameras and pedestrian buttons that allow signals which previously ran on fixed time to self-adjust to fluctuating traffic patterns and run more efficiently.
Current plans call for eight intersections on Thomas, Dougherty and Pulaski Streets, which form part of the downtown perimeter, to receive these upgrades by the end of the fiscal year in June.
Actuating intersections on Broad from Newton Street to Thomas Street would be the next step in the process, although the project, taking place on a state-maintained highway, requires partnership with the Georgia Dept. of Transportation and therefore more time.
Decker says rebuilding the signals on the bordering streets will improve the flow of traffic around downtown and better complement the fixed-time system still in place at intersections inside that boundary.
“What we’re trying to do is get the traffic flow on those four roadways and eventually Broad to go around the city, then when you’re leaving it should allow you to get around much more quickly and reduce the delays and congestion,” Decker said. “I would prefer that the bordering streets all be actuated. That way I can do a much better coordination system. It’s not working to the degree that I’d like it to work.”
Actuation is the antithesis of “coordination,” whereby traffic signals run on preset cycle lengths determined by studies of traffic volume at different times of day. Athens-Clarke County currently runs 11 coordinated signal systems chains of related intersections on or adjoining major roads or in a particular area that are calibrated to optimize traffic flow and efficiency. One of these networks covers the downtown area, also known as the central business district (CBD).
Planners and traffic engineers make common practice of using coordination in CBDs like downtown Athens where intersections are equally-spaced and in close proximity to one another. Consistent traffic flow in all directions allows these signals to run efficiently together, and they’re cost-effective, according to a handbook by Robert L. Gordon on signal timing practices in the U.S.
But what’s atypical about downtown Athens is Broad Street, which is more of an arterial highway fed by tributary roads than a downtown street crossing with traffic paths of equal significance. Broad’s size and traffic volume are both greater than that of any of the streets that intersect it, yet the signals at its intersections operate as if their traffic patterns are comparable.
These signals often give more time to movements on secondary streets than is needed, forcing those on the main road to wait on traffic that has already cleared the intersection. Because of coordinated signals’ inability to sense real-time changes in traffic patterns, intersections like those on Broad operate below optimal efficiency and often intensify congestion.
“Waiting when there’s nobody there – that’s a lot of unnecessary delay,” Decker said. “That goes away with actuation. Time goes back to the main street and it reduces people sitting there.”
Decker says the plan to upgrade the intersections on the perimeter streets should amount to a 20-30 percent improvement in efficiency.
“Efficiency is fluctuating,” he said. “Our goal is to try to make it as efficient as possible.”
Congestion, while never significant, makes the difference of several minutes added onto the commute through downtown for motorists.
“It’s pretty annoying,” UGA junior Andy Bedingfield said of the traffic he’ll sometimes experience downtown around 5 p.m. “There’ve been times that a place I’d normally get to in 10 minutes would take 20 or more.”
Cars aren’t the only vehicles that have problems with congestion downtown.
Buses on Campus Transit’s East-West route shuttle passengers from west campus through downtown via Broad Street toward the main library.
Jerod Beck, a sophomore from Dacula, drives the East-West route during the noon hour on Mondays when traffic reaches its midday height due to UGA’s 12:05 class change and a tide of motorists headed to lunch.
Cars traveling east stack up on Broad between Lumpkin Street and the arch bus stop near College Avenue, making it hard for buses like his to make their way back into the right-of-way. This ordeal adds five to seven minutes to the time it takes him to get between stops at Hull Street and the Main Library, in essence doubling the time it takes for passengers to ride that portion of the route.
“All the delay is primarily due to moving in and out of the arch bus stop,” Beck said. “We’re dependent upon other buses, courtesy of other drivers or open space to merge back in.”
The plan will offer moderate benefits to pedestrians. Crosswalk signals downtown will now have buttons on them to record the presence of foot-traffic waiting to cross the road.
A number of pedestrians surveyed said they generally had no problems with delays while walking downtown.
UGA student Sophie Archer, who lives downtown, said traffic at the Broad-College intersection is bad at certain times of day, but never delays her as a pedestrian.
Another student who frequently walks through downtown said the wait time to cross is not a problem for her. “It doesn’t make me late to class or anything,” she said.
Both, however, said they would be in favor of improvements to the intersection if it made things faster.
Actuating intersections involves installation of either “inductive loops,” electronic sensors embedded in the pavement behind an intersection’s “stop bar,” or mounted cameras. Either or both of these technologies serve to detect vehicles as they roll up, and feed that information into a computer that also takes input from pedestrian “push for walk signal” buttons and adjusts the timing of cycle patterns accordingly.
Outside of programming, the process of putting this equipment in place isn’t extensive. Decker’s staff cuts their own sensor loops, and he says they can usually get everything done for a given intersection in a day or two. But gadgetry for all the intersections must be in place before they can program the network and flip the switch.
A number of factors hold his office back from completing the project. Staff limitations have forced them to make upgrading the intersections a side project balanced with other priorities related to traffic signals, street markings and signage across town.
Ill-timed construction and maintenance work downtown has undone much of their progress in the past year.
Construction of The Standard on the corner of Thomas and Dougherty streets destroyed the instruments that were already in place at the intersection. A recent road resurfacing project downtown also invalidated much of the work they’d done and forced them to start over.
“We’re doing it as we can,” Decker said. “Every time we start on it something happens.”
The costs of the actuation updates are within their budget, since signal efficiency upgrades fall within a stated goal of ensuring “maximum roadway capacity and reduced delay at signalized intersections through a comprehensive signal upgrade and signal system re-timing program” outlined in last year’s Transportation and Public Works biennial report.
Sensor loops, according to Decker, cost between 300 and 500 dollars. Combined with the cost of programming and other required mechanisms like wiring, buttons and signal heads, actuation upgrades can add up to a price tag of thousands of dollars apiece – a ballpark figure of 250,000 dollars, according to the ACC Traffic Engineering Division webpage.
Is shaving off a few minutes from the commute time through downtown worth that cost?
Decker believes the project will return on the investment once the upgrades to Broad Street are fully completed. The congestion issues that continue in the meantime, he says, aren’t serious.
“It’s not efficient,” Decker said, “but it will be once GDOT does the project. (Otherwise) the downtown central business district works really well. We’re blessed because we don’t have major traffic issues like Atlanta does.”