Ice jams cause substantial damage to highways and bridges yearly; however, the highway engineer often is not familiar with what causes them, how to remove or prevent them, or how to lessen their damage-causing potential. Presented in this paper are the basic types of ice and how to recognize themi how they might cause ice jams to form, where they might occur, how to remove them, how to prevent them, and how to compute the height they might reach. With this information the engineer should be aided in his design or reconstruction of highway facilities so that they will not be affected by, or cause, ice jams.