Washington ? Highway construction zones too often are death zones for motorists and workers, federal safety investigators said Tuesday in urging the government to come up with ways to make the areas safer.

The National Transportation Safety Board made the recommendation in a report that cited poor work zone design as the probable cause of a 2001 Nebraska bus crash that killed three high school students and a chaperone.

While drivers cause many accidents by excessive speed or inattention, the safety board said state highway departments bore some responsibility. Too often, work zones have lanes that are too narrow, inadequate barriers separating oncoming traffic and design flaws, the safety board said.

“It is the responsibility of government to secure the highways for safety for experienced and inexperienced drivers,” Chairman Ellen Engleman Conners said. “We don’t have an inexperienced driver lane.”

On major highways, state governments usually are responsible for planning the design of construction zones and ensuring the work is done correctly, whether by public employees or private contractors.

The board unanimously asked the Federal Highway Administration to issue stronger rules for designing work zones, such as concrete barriers or orange barrels to separate two-way traffic, and to require regular monitoring of the zones so their designs can be modified quickly if accidents occur.

The board also told the administration to require that contractors maintain safety features such as bridge railings during work projects.

Engleman Conners said she planned to take the board’s findings to a meeting of state transportation officials today.

Construction zones have become more common as many cities and towns seek to accommodate growing populations and upgrade outdated roadways. As they proliferate, so do accidents.

Emergency personnel work the scene of a bus accident in which a school bus carrying band members from Seward High School fell off the side of a low bridge in this Oct. 13, 2001, file photo in Omaha, Neb. In a report released Tuesday, the National Transportation Safety Board cited poor work zone design as the probable cause of the crash that killed three students and a chaperone.

The number of motorists and workers killed in construction zones rose from 693 in 1997 to a record 1,181 in 2002, according to the National Highway Traffic Safety Administration.

Jennifer Gavin, a spokeswoman for the American Association of State Highway and Transportation Officials, said drivers bore most responsibility for work zone crashes.

“The vast majority are caused by speeding and inattention,” she said of fatal work zone accidents.

The Nebraska crash occurred on Oct. 13, 2001, along a stretch of U.S. Route 6 in Omaha. Normally a six-lane divided highway, the road had been narrowed to two lanes separated only by a double-yellow line as it neared a work zone at the West Papillion Creek Bridge.

The bus carried 27 high school band members and three adults. The driver swerved to avoid an oncoming bus, went off the road and broke through a guardrail that had been damaged months earlier but not repaired completely. It came to rest on its side in the creek below the bridge.

The National Transportation Safety Board investigators told the board the lanes at the construction zone were so narrow they offered no margin of error for two approaching buses.