- Associated Press - Monday, June 2, 2014

KANSAS CITY, Mo. (AP) - Missouri transportation officials have shelved a project using “sound cannons” to warn distracted motorists to slow down in work zones, but remain interested in how that technology could protect highway workers.

Researchers tested the long-range acoustic devices - or LRADs - in November on Missouri Department of Transportation vehicles on Interstate 435 in northern Kansas City and on Interstate 70 near Columbia.

They mounted the device on the back of MoDOT trucks pitched at a 90 degree angle to face drivers approaching from behind. When a vehicle came too close, drivers heard a high-pitched sound and the message “slow vehicles ahead.”

The devices were developed for the U.S. military by LRAD Corp. to warn strangers getting too close to ships, and have been used to protect convoys in Iraq, warn pirates on the high seas and disperse demonstrators in New York and Pittsburg, The Kansas City Star (http://bit.ly/1puWbkJ ) reported.

E. Brian Harvey, an LRAD Corp. spokesman, said the Missouri transportation department was the first to suggest using the device on highways. The San Diego-based company now markets it to other highway departments nationwide.

Motorists have hit slow-moving MoDOT crews 44 times in the past two years, said department spokeswoman Holly Dentner. Since 2000, 16 transportation department employees have died on the job, including Clifton Scott, a Kansas City-area motorist assist employee killed by a drunken driver on Interstate 70 in 2012.

Results are expected soon of a $49,000 University of Missouri study funded by federal planning and research money to explore how the devices could protect highway workers.

But some people oppose the plan, warning that the loud warnings could startle drivers and cause accidents, and lawmakers in Jefferson City have questioned why the transportation department spent money on the devices without getting legislative approval.

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Information from: The Kansas City Star, http://www.kcstar.com