Expect to see flashing yellow arrow signals at more Eagan intersections this year.
On Tuesday, the Eagan City Council unanimously approved the installation of two new flashing yellow arrows signals—one at the intersection of Pilot Knob Road and Wescott Road, and the other at the intersection of Lexington Avenue and Northwood Parkway
The new signals aren't the first of their kind in Eagan, and they probably won't be the last, according to Eagan Transportation Manager Tim Plath. The arrows indicate that a driver making a left turn at an intersection can proceed with caution after yielding to any oncoming vehicles. The innovative signals are favored among Dakota County and Eagan officials, who believe they improve the flow of traffic and are easily understood by motorists.
The city has already installed five such signals at intersections across the city. The first signals were installed along Yankee Doodle Road in 2009, Plath said. Last year, more were added to Lexington Avenue. Eagan was the first community in Dakota County to sport the new signals, according to information released by city officials at the council meeting on Tuesday.
Installing the two new signals may cost as much as $100,000, according to city officials. Because the signals are being implemented at the intersection of city and county roads, half that amount will be paid by Dakota County, and half will be covered by the city, Plath said. The city's portion will be drawn from Eagan's major street fund.
Engineers consider a number of factors when evaluating whether an intersection could benefit from a flashing yellow arrow signal, Plath said.
Intersections must have dedicated left-turn lanes and signal poles strong enough to bear the weight of an additional signal box, Plath said. Additionally, the intersections must be easily visible by approaching motorists, so that the installation of the new signals doesn't create a possible traffic hazard. City and county officials also take into account the proximity of the intersection to other flashing yellow arrow signals.
The popularity of the flashing yellow arrow signal has grown in recent years. U.S. Department of Transportation officials see it as an answer to the traditional—and sometimes ambiguous—green circle signal, according to this department memo. Department engineers worry that some motorists mistake the green circle as an indication that cars turning left have the right-of-way over oncoming traffic.
The flashing yellow arrows, which are added to the traditional yellow, red and green turning signals, also give motorists more opportunities to turn, Plath said.
"It really does reduce the time that vehicles have to wait at an intersection," Plath said. “This is what I would consider a low-cost, high-benefit method of increasing our efficiency."