"When I first saw them I didn't know if I should go ahead and turn or just stop."
That was the reaction from a number of Cornelius residents about the new flashing-yellow-arrow signals installed along a newly widened stretch of West Catawba Avenue between U.S. 21 and Jetton Road.
The new style of left-turn signal, adopted as part of a Federal Highway Administration study, is designed to make it easier for drivers to know when to turn left: When they see the flashing yellow arrow, left turns are permitted, but drivers must yield to oncoming traffic.
The signals also will reduce instances in which, previously, green left-turn signals changed to the traditional round red stop signal,, trapping cars turning left in the intersection while oncoming traffic continued to flow. Cornelius and N.C. Department of Transportation officials are hoping the signals will improve safety and the flow of traffic.
"The state DOT has been using these signals on a trial basis since 2005, and we're finding they are more effective than the traditional solid green ball in conveying to motorists the need to yield before turning left," said Scott Cole, Division Traffic Engineer at the DOT's Albemarle office.
Cole said some motorists erroneously interpreted the older "green ball" signal as an indication to "go ahead and make a left turn" without regard to oncoming traffic or pedestrians.
The flashing-yellow left-turn signals have been installed at West Catawba Avenue's intersections with U.S. 21, Torrence Chapel Road, One Norman Boulevard, Bethel Church Road and Jetton Road in Cornelius, as well as several locations in Huntersville and on N.C. 150 in Mooresville.
The results so far are encouraging.
"In Cornelius, there have not been any accidents to date that can be attributed to the flashing-yellow arrows," said Assistant Town Manager Andrew Grant.
"Without question, traffic flow has also improved at the intersections with the flashing-yellow arrows," said Grant. "It allows left-turn traffic more opportunities to move left and allows other vehicles more time to make their movements through the intersection.
"Other areas around the state have implemented this and are seeing the same benefits."
Adopted elsewhere, too
In fact, many states are beginning to use them.
Virginia, for example, recently began using them in the Roanoke area, after a successful trial at the entrance to Busch Gardens in Williamsburg.
Kentucky began using the new signals this spring around Bowling Green. Michigan has decided to replace all its flashing red lights with flashing yellows, saying the new lights prevent accidents, move traffic through an intersection faster and give traffic engineers more options for handling volume.
Other states are taking a more cautious approach.
"We have no plans to use them at this time," said Tony Sheppard, Director of Traffic Engineering for the S.C. DOT. "We'll monitor how they work out in other areas and then make a decision."
Locals react hesitantly
Cornelius residents had mixed reactions, centered mostly on reasons to be cautious about the new signals.
"They do get your attention, but I'm concerned about the ability to see oncoming traffic at certain locations, especially the left turn for eastbound traffic at One Norman Boulevard near Bank of America," said Mabel Culbreth.
Cole said traffic officials will carefully monitor the signals and make changes if conditions warrant. "We're trying to be logical about their application."
Several other residents thought motorists should have been notified somehow before the signals were installed.
"They were confusing at first, and neither the town nor the state did anything that I ever saw to educate us on the new lights," said Cornelius resident Rod Beard.
Grant admitted motorists "are going through a quick learning curve the first time they encounter the flashing yellow arrows."
Benefits vs. expense
As with most improvements, cost also must be considered. State officials estimate the added equipment costs about $4,000 per signal. Cole says the anticipated benefits, however, justify the expense.
"Preliminary statistics indicate that these signals can reduce angle collisions by as much as one-third," said Cole. "The bottom line is that we believe this system will save lives."