Under the influence of a theoretical approach that blends principles drawn from environmental criminology, routine activity theory, rational choice theory, and situational crime prevention doctrine, police have become actively involved in analyzing and intervening in both the potential crime problems associated with new property development and in specific, fully developed crime problems. Crime prevention through environmental design in British Columbia is broad. Approaches have been based on what is known about how target choices are made and what can be done to eliminate specific criminal acts, nuisance activities, or frightening situations. To date, police activities in this area have included alterations in the design and building of a new town in the undeveloped northern part of the province, modifications in the design and building of a rapid transit system in the Vancouver metropolitan area, and changes in road and pedestrian traffic networks. Others have included alterations in the design and development of a new tourist area, changes in parks and how they are used, and changes in activities around schools and shopping areas. Most changes have focused on increasing opportunities for surveillance and reducing opportunities for criminal activities. 1 table, 15 notes, and 9 references.