According to the National Institute for Occupational Safety and Health, most work-zone fatalities are due to a heavy truck or machine striking a ground worker, and half those deaths occur when a vehicle is backing up. Contractors looking to improve safety are pushing machinery suppliers to offer object-detection technology, which is now common on new cars and light trucks.

With their large wheels, rear counterweight and pivoting boom, telescopic handlers, or telehandlers, are one type of machine being targeted. Balfour Beatty Construction has a national agreement with Sunbelt Rentals to install proximity alarms on any telehandler shipped to jobsites, and safety executives say they are an important risk-management tool.