This synthesis will be of interest to traffic engineers, planners, and others interested in how highway agencies deal with freeway incidents. Information is provided on the procedures and processes that highway agencies use to respond to traffic congestion caused by incidents on freeways. Congestion on freeways frequently is caused by incidents such as stalled vehicles or accidents that reduce the capacity of the freeway below the level of demand. This report of the Transportation Research Board describes the procedures and processes used by states to respond to traffic congestion caused by incidents on freeways.  The report for this topic can be purchased at https://www.trb.org/news/blurb_detail.asp?id=3401