This Innovations Deserving Exploratory Analysis (IDEA) project applied a laser technology, previously developed for military application and known as Multiple Integrated Laser Engagement System (MILES), to develop a portable warning system to improve work zone safety for highway workers. A prototype system was developed and successfully demonstrated. The road crew warning system consists of a laser transmitter, one or more laser receiver-transmitters, and a worker notification system. These components together provide a laser barrier along the border of the work zone. Additional receiver-transmitter sets can be employed to extend the barrier or change the beam direction to accommodate other warning-zone geometries. The warning system provides additional time for the workers to take evasive action.