2.8.3 – Drivers Who Are Hazards In order to protect yourself and others, you must know when other drivers may do something hazardous. Some clues to this type of hazard are discussed below. Blocked Vision. People who can't see others area very dangerous hazard. Be alert for drivers whose vision is blocked. Vans, loaded station wagons, and cars with the rear window blocked are examples. Rental trucks should be watched carefully. Their drivers are often not used to the limited vision they have to the sides and rear of the truck. In winter, vehicles with frosted, ice-covered, or snow-covered windows are hazards. Vehicles maybe partly hidden by blind intersections or alleys. If you only can seethe rear or front end of a vehicle but not the driver, then he or she can't see you. Be alert because he/she may back out or enter into your lane. Always be prepared to stop.