The state will close Eubanks between Rogers Road and Old N.C. 86 for construction of a roundabout to serve the new Morris Grove Elementary School opening in August.

The school will add an estimated 820 vehicle trips a day to Eubanks Road, which has about 2,500 trips a day now, according to the state Department of Transportation.

That portion of the road will be closed until April 30.

Why a roundabout?

It's safer.

"Roundabouts are being looked at more and more," DOT district engineer Chuck Edwards said. "They can process quite a bit of traffic safely and efficiently."

A study in 2001 of 23 intersections in the United States found that replacing traffic signals or stop signs with roundabouts reduced injury crashes by 80 percent and all crashes by 40 percent.

With traffic signals, the most common crashes are right-angle, left-turn, and head-on collisions, according to the Insurance Institute for Highway Safety, which did the 2001 study. Roundabouts eliminate these by keeping vehicles traveling in the same direction -- counterclockwise -- at low speeds.

"Installing roundabouts in place of traffic signals can also reduce the likelihood of rear-end crashes and their severity by removing the incentive for drivers to speed up as they approach green lights, and by reducing abrupt stops at red lights," the institute reported.

How common are they?

This will be Orange County's first roundabout on a state-maintained road, said Jim Dunlop, DOT congestion management engineer. There are about 40 in North Carolina, including one at old Erwin Road and N.C. 751 in Durham. "We probably have at least that many [more] on the books," Dunlop said.

The first modern roundabouts in the United States were built in 1990, and there are now about 1,000 across the country, according to the insurance institute. There are about 20,000 in France, 15,000 in Australia, and 10,000 in the United Kingdom, the institute says.

Are they cheaper?

No.

Dunlop said most roundabouts cost $250,000 to $400,000.

Bill Mullin, director of facilities management for the Chapel Hill-Carrboro City Schools, which is building the roundabout, could not separate its cost from the cost of the overall school project, but said it would run in the "hundreds of thousands of dollars."

Installing a traffic signal -- without widening roads or adding turn lanes -- typically costs $100,000, Dunlop said. But signals have about a 15-year life span and maintenance costs, he added.