Top of I-285 to get variable speed limit signs

The top end of I-285, between I-20, will get variable speed limit signs and the top speed will increase to 65 miles per hour, with system tests starting in August. Photos by Lauren Ramsdell

The maximum speed limit on I-285 north of I-20 will increase to 65 beginning Sept. 1, according to a memo from the Georgia Department of Transportation (GDOT).

Sixty-five is only the maximum, though. The memo states GDOT will be implementing variable speed limit (VSL) signs along the “top end” of I-285. This is in an effort to prevent traffic congestion and accidents, the release says.

Some benefits touted by the release include breakups of stop-and-go traffic incidences, reduced rear-end and lane-change collisions, and decreased idling.

The speed limit on the southern half of I-285 was increased to 65 miles per hour in November 2013. At the time, officials said due to the low volume of traffic, increasing the southern portion was safer than increasing the northern portion.

“We have actually done some follow-up studies and we found that average speed on the [I-285, south of I-20] corridor didn’t change very much,” said Andrew Hoenig, a spokesperson with GDOT. “It’s much more congested [on I-285, north of I-20] so you have speed that fluctuates a lot more so it’s less safe.”

Hoenig said that the studies have shown, despite a 10-mile-per-hour speed limit increase, the average top speed of vehicles on the bottom end of I-285 increased by just one mile per hour.

Now GDOT officials are saying that, with the variable speed limit, adjustments can be made in real time, increasing safety. The memo points out that Northside traffic during peak hours already travels under 65 miles per hour.

“VLS addresses a safety issue,” Hoenig said. “There are many more interchanges on the north side so we have weaving up on the upper portions, which can be dangerous. Now we will try to more closely match what is actually happening.”

The increased speeds will not actually cause more accidents, said Lieutenant Wade Chaffin of the Georgia Department of Public Safety, and may, in fact, be safer than a speed limit lower than how drivers typically behave anyway.

“Speed in and of itself is not the ultimate cause of these accidents,” Chaffin said. “NASCAR has speeds of up to 200 miles per hour, so if we were all doing that and turning left it would be fine. But we have external input: from the dawn of car creations, we have had radios, getting fast food and trying to eat a four course dinner in your lap, put on makeup and do yoga.”

He further said that slow drivers, those going below the speed limit or below the rate of flow of traffic, can be a bigger problem than those travelling fast.

During peak times and when accidents occur, the Transportation Management Center will reduce the speed limit. The overhead signs will alert drivers to the decreased speeds, which will drop in increments of 10 miles per hour. Georgia also has a law that grants drivers 500 feet from the start of a new speed limit to comply with that limit before a citation can be issued. The limit will never decrease below 35 miles per hour, the memo states.

“For the top end that is not a bad ability,” Chaffin said. “Our folks will have to be mindful of what is actually posted at the time, and enforce that adequately. We have always–I speak for myself –but we always give benefit to the violator, especially in a changing speed limit area.”

Hoenig admits that the recent speed limit change on the south end has actually not produced a change in driving habits; he predicts the new signs also will not have a dramatic effect on top speeds.

“When we raised the speed limit on the bottom end, top speeds really did not increase,” he said. “We recognize that people are going above 55. The average speed on a Sunday afternoon with low traffic conditions is usually well above that. But, we are not going above 65 miles per hour. That’s what we are allowed to do under Georgia law.”

Instead, Hoenig said, the new signs will make the top end safer by slowing drivers down well in advance of any gridlock.

“A good example is a funnel,” he said, “If you pour a whole bunch of rice in a funnel it will get stuck and go through slowly. But, if you slowly pour it in, it will all go through much faster.”

This article originally appeared in The Champion Newspaper.