Speed-limit decrease violates law
McClatchy Newspapers

BLUFFTON - A 20 mph speed-limit decrease on a busy - and heavily radar-patrolled - state highway is too abrupt, according to the state Department of Transportation.

On Thursday, The (Hilton Head) Island Packet reported the story of Michael Hartley, a 42-year-old Bluffton man who successfully fought a speeding ticket by arguing he didn't have enough warning to slow down. He doesn't dispute he was driving 20 mph over the limit near a construction zone.

A jury tossed out his speeding ticket, which would have cost $350 and added four points to his license.

"If you're going to drop the speed that quickly," he said, "you need to give us a more reasonable distance to reduce our speed."

Hartley is right.

Federal guidelines indicate the warning sign should be posted at least 950 feet before the speed limit drops from 55 mph to 35 mph, said Trans-portation Department construction engineer Mark Nesbit.

On westbound S.C. 46/170, drivers only have about half that distance to react, roughly 500 feet, before the slower speed takes effect in the middle of a curve.

"I'm not sure what the situation is there," said Nesbit, whose office initially approved signs for the New River bridge project. "Sometimes there's a physical restriction, so we have to shift it forward if there's some sort of reason we can't mount it exactly at 950 feet."

Nesbit said someone from his office will take a look at the sign's position.

"If we need to relocate it, we definitely will," he said.

Guidelines on the position of warning signs are based on several studies about how long it takes motorists to read, interpret and react to the message at varying speeds, Nesbit said.

On average, the Bluffton Police Department conducts aggressive enforcement on the stretch of road about twice a week because of its high accident rate, said police Chief David McAllister.