The problem with left-side exits

From today's AJC:

When highway engineers design traffic control devices, a major thing to consider is a concept called driver expectancy," Hanscom said. "When we design signs, we have to know how drivers behave.

"A major problem is that this [the Northside Drive HOV ramp] was a left-hand exit," said Hanscom, who noted he has not studied this particular ramp. "Most off-ramps in the United States are right-hand exits. Left-hand exits violate driver expectancy."

That doesn't mean they should not be used, he said, it means traffic engineers have to prepare drivers for the upcoming left-hand exit. If a sign is only at the exit itself, Hanscom said, "that's too late."

"There are a lot of principles of highway signing that may be violated here [approaching the Northside Drive ramp]," Hanscom said.

The AJC's coverage of the Friday's bus accident also includes a video from the driver's perspective, although unlike in the video, it was dark when the accident occurred.