Caltrans workers and the California Highway Patrol were be out in force Tuesday on highways throughout the state, installing “Move Over” signs intended to help save lives and increase safety for motorists, highway workers, CHP officers, and other law enforcement.

“Every day, highway workers put their lives in danger just by going to work,” Caltrans Director Malcolm Dougherty said in a prepared statement. “We’re asking motorists to slow down, watch out for highway workers and CHP, and safely move over a lane when they see flashing amber lights on Caltrans or other emergency vehicles.”

The new signs will display the messages, “Move Over or Slow for Stopped Emergency and Maintenance Vehicles” and “Move Over or Slow When Amber Lights Flashing.” In addition, more than 700 existing electronic highway message signs statewide will display, “Move Over or Slow for Workers, It’s the Law.”

The Move Over law, which took effect in 2007, was amended in 2009 to add Caltrans vehicles displaying flashing amber warning lights to the list of vehicles for which motorists must move over if safe to do so, or slow down.

Highway construction and maintenance work is one of the most dangerous occupations in the United States. Since the 1920s, 178 Caltrans employees have died while on the job.