The bottom line in IVHS is a reduction in congestion, safer highways, and reduced fuel consumption and pollution. Law enforcement agencies can also use IVHS techniques to enforce weight and safety regulations, keep tabs on hazardous material movement, and locate stolen vehicles. IVHS covers a lot of ground including heavy vehicle and commercial operations, advanced traffic management systems, advanced driver information systems, and automatic vehicle identification (AVI), weigh-in-motion, and automatic vehicle classification. AVI spots vehicles using a form of electronic bar coding where transponders on the vehicle send a unique coded signal to an antenna embedded in the pavement. AVI equipment like electronic transponders or a bar code attached to the window to keep track of toll highway users allows tolls to be billed to them or put on their credit cards. Automated traffic management systems are expected to do more than just monitor traffic conditions and advise drivers. They will perform real-time incident management, control traffic patterns to reduce congestion and even provide routing information to individual drivers. Obstacle and collision detection technology is also being developed.