Lots of approaches are under way to reduce deer collisions, but few have proven effective.

Studies show that deer-vehicle collisions are on the rise. Typical strategies to reduce the number of these collisions include modifying driver behavior, modifying deer behavior, and reducing the number of deer. Installing fencing that is sufficiently high, long, and strong has been proven to work. Temporary warning signs, posted during seasons when mule deer migrate, have also been proven effective. A more controversial method is to reduce the size of herds. While clearing away foliage that attracts deer from alongside roadways holds promise, more studies need to be done to confirm the effectiveness of this method. Research on the effectiveness of reflectors and mirrors on highways has also been mixed. Studies have shown that attaching whistles to cars in order to warn deer away has no effect whatsoever. In order to determine what steps need to take in the future to reduce deer-vehicle collisions, more detailed data on deer-collision crashes are needed, including data indicating the precise location of collisions.