Publication Number: FHWA-HRT-04-022
Date: January/February 2004

Shields of Steel: California Introduces New Mobile Work Zone Protection Device

In January 2001, two California Department of Transportation (Caltrans) highway maintenance workers were hit by an impaired driver whose car penetrated a work zone. One of the workers, Mark Balsi, lost a leg in the accident. From that tragic incident has come an innovation designed to significantly improve safety for workers along the Nation's highways.

"Protecting our workers and the traveling public are our highest priority," says Randell Iwasaki, Caltrans Deputy Director for Maintenance and Operations. "The accident involving Mark Balsi underscored the need for additional protection from vehicles that could penetrate the work area. The result of our research and deployment efforts was the development of the Balsi Beam, a mobile work protection system."

The system, which is carried on a tractor-trailer, is specifically intended to enhance worker safety when carrying out shoulder repair in work zones adjacent to guardrails, bridge rails, and soundwalls. Each side of the trailer consists of high-strength steel box section beams that are capable of extending an additional 4.6 m (15 ft). Using hydraulic power, each beam can rotate to either side (left or right), depending on which side of the road a protective barrier is needed. The trailer then extends to provide a 9.1-m (30-ft) secure work zone. The trailer beams act as a rigid obstacle to deflect traffic away from maintenance workers, in essence forming what Caltrans calls "shields of steel" to protect workers. The system reverses the procedure for transport. Whereas in a typical work zone, trucks are in the front and back of the work zone but there is no protection from vehicles in adjacent traffic lanes for workers, use of the system "lengthens out the area where workers are protected," says Iwasaki.

The system "performed exceptionally well in testing," says Cal Schiefferly, Senior Equipment Engineer in the Caltrans Division of Equipment. "We were very satisfied with the results." The device is now being used in Caltrans' District 4, which serves the San Francisco Bay area. After gaining experience in operating the device there, Caltrans plans to deploy it elsewhere in the State. The prototype device cost approximately $217,000 to build, but Caltrans expects that cost to drop significantly when other models are produced.

A patent for the Caltrans system is pending. State highway agencies can obtain more information, as well as plans for constructing the device, by contacting Lisa Kunzman, Chief of the Caltrans Division of Equipment, 916-227-9600 (email: Lisa_Kunzman@dot.ca.gov).

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