As highways become more congested due to increased resurfacing, restoration, rehabilitation, and reconstruction (4R), it has been found that accident rates also rise. In North America in the 1990s, a great number of construction workers and motorists were injured or killed in or near work zones. This paper reviews the rehabilitation processes, highway configurations, and work strategies commonly used in Canada and the U.S. In addition, the primary root causes for incidents (traffic congestion, work zone duration, the length of work zones, and traffic speed in work zones) are outlined. Finally, innovative strategies and some new technologies are provided to improve work zone safety.