Abstract: Terrain maps, commonly used for updating elevation values of a moving object (i.e., a traveler), may be conveniently used for detecting and preventing collisions between the traveler and other objects on the scene. For that purpose, we project the geometry of all collidable objects onto the map and store it in a dedicated color channel. Combined with adaptive speed control, this information provides fast and reliable collision-avoidance during travel, independent of scene complexity. We present implementation details of the base system for a Virtual Reality application and discuss a number of extensions.