Motorists in Woodbury are among the first in the nation to encounter a new traffic signal design that minimizes unnecessary waiting for motorists and improves safety.

The new signals feature a flashing yellow arrow, in addition to the standard red, yellow and green arrows. When illuminated, the flashing yellow arrow allows waiting motorists to make a left turn after yielding to oncoming traffic. Otherwise, the new traffic signals work the same as traditional signals.

The new signals, at the Interstate 94 and Highway 95 interchange in Woodbury, represent a major change in traffic signal operation, according to the Minnesota Department of Transportation.

“This is the biggest change in traffic signal design and operation in the past 40 years,” said Jerry Kotzenmacher, MnDOT senior engineering specialist. “We have shop-tested these signals for many months and are confident the signals will improve safety and reduce congestion.”

In December 2009, after extensive testing, the Federal Highway Administration authorized use of flashing yellow arrows nationwide. Some Minnesota cities and counties have already installed the new signals on city and county roadways. MnDOT expects to install several systems by the end of 2010.

A study conducted by the National Cooperative Highway Research Program determined that drivers had fewer crashes with flashing yellow left-turn arrows than with traditional yield-on-green signal configurations.