More than 1.5 million traffic crashes involving deer occur each year in the U.S. These crashes produce $1.1 billion in vehicle damage & 150 fatalities annually. Deer-related crashes are increasing as both deer populations & vehicular travel increase. Many methods have been used in attempts to reduce deer crashes, often with little scientific foundation & limited evaluation. This paper summarizes the methods & reviews the evidence of their effectiveness & the situations in which each may be useful. The only widely accepted method with evidence of effectiveness is well-designed & maintained fencing, with underpasses or overpasses as appropriate. Other methods using advanced technology require substantial additional research & evaluation.