Collision avoidance in transportation

In transportation, collision avoidance is the maintenance of systems and practices designed to prevent vehicles (such as aircraft, motor vehicles, ships, cranes and trains) from colliding with each other. Examples include:
 * Airborne collision avoidance systems for aircraft
 * Automatic Identification System for collision avoidance in water transport
 * Collision avoidance (spacecraft)
 * Collision avoidance system in automobiles
 * Positive train control
 * Tower Crane Anti-Collision Systems