ODOT utilizes `dilemma zones'

7/6/2003

Once a rural corner gets a traffic signal, it isn't long before motorists start clamoring for an advance blinker to alert them before the light goes red.

But Ohio Department of Transportation officials say they're increasingly reluctant to put up those lights that start flashing ahead of a signal's progression from green to yellow to red, because many drivers respond by speeding up - to try to beat the light - instead of rolling to a gentle stop.

As an alternative, all ODOT-operated traffic signals in Ohio's northwestern-most eight counties have been equipped with “dilemma zone” circuitry that extends the green for an approaching vehicle if it passes over a sequence of sensors 240 and 180 feet before the signal.

“The dilemma zone works better than flashers, because a motorist approaching a signal can be assured that, if he's going the speed limit, he'll get through,” said Mike Ligibel, planning and programs administrator at ODOT's district office in Bowling Green.

There's a limit to how much extra time the “dilemma zone” can provide. If one vehicle after another passes over the sensors, eventually the light will reach a maximum amount of green time and turn red to give intersecting traffic a turn.

At a selected few locations, the transportation department is taking an extra step to remind motorists when the light is red, too: a thin, flashing strobe light in front of the red lens.

Such strobes have been widely used in Pennsylvania, New York, and other states, primarily along major roads that have fairly high speed limits and have signals that are located either at the end of a long stretch of unimpeded driving, or in a commercial area with lots of lights and bright signs.

The latter is the situation on Central Avenue at King Road, where strobes recently went in, said Mike Stormer, ODOT's district planning engineer.