Conrad 1:50 MAN TGS NN Winter Service Truck 3-axle w/Gritting Structure & Snow Shield & Crane

A winter service vehicle (WSV), or snow removal vehicle, is a vehicle specially designed or adapted to clear thoroughfares of ice and snow. Winter service vehicles are usually based on a dump truck chassis, with adaptations allowing them to carry specially designed snow removal equipment. Many authorities also use smaller vehicles on sidewalks, footpaths, and cycleways. Road maintenance agencies and contractors in temperate or polar areas often own several winter service vehicles, using them to keep the roads clear of snow and ice and safe for driving during winter. Airports use winter service vehicles to keep both aircraft surfaces, and runways and taxiways free of snow and ice, which, besides endangering aircraft takeoff and landing, can interfere with the aerodynamics of the craft.

The earliest winter service vehicles were snow rollers, designed to maintain a smooth, even road surface for sleds, although horse-drawn snowplows and gritting vehicles are recorded in use as early as 1862. The increase in motor car traffic and aviation in the early 20th century led to the development and popularisation of large motorised winter service vehicles.

A gritter, also known as a sander, salt spreader or salt truck, is found on most winter service vehicles. Indeed, the gritter is so commonly seen on winter service vehicles that the terms are sometimes used synonymously. Gritters are used to spread grit (rock salt), onto roads. The grit is stored in the large hopper on the rear of the vehicle, with a wire mesh over the top to prevent foreign objects from entering the spreading mechanism and hence becoming jammed. The salt is generally spread across the roadway by an impeller, attached by a hydraulic drive system to a small onboard engine. However, until the 1970s, the grit was often spread manually using shovels by men riding on the back of the truck, and some older spreading mechanisms still require grit be manually loaded into the impeller from the hopper

Salt reduces the melting point of ice by freezing-point depression, causing it to melt at lower temperatures and run off to the edge of the road, while sand increases traction by increasing friction between car tires and roadways. The amount of salt dropped varies with the condition of the road; to prevent the formation of light ice, approximately 10 g/m2 (2.0 lb/1000 sq ft; 0.018 lb/sq yd) is dropped, while thick snow can require up to 40 g/m2 (8.2 lb/1000 sq ft; 0.074 lb/sq yd) of salt, independent of the volume of sand dropped. The grit is sometimes mixed with molasses to help adhesion to the road surface. However, the sweet molasses often attracts livestock, who lick the road.

Gritters are among the winter service vehicles also used in airports, to keep runways free of ice. However, the salt normally used to clear roads can damage the airframe of aircraft and interferes with the sensitive navigation equipment. As a result, airport gritters spread less dangerous potassium acetate or urea onto the runways instead, as these do not corrode the aircraft or the airside equipment.

Gritters can also be used in hot weather, when temperatures are high enough to melt the bitumen used in asphalt. The grit is dropped to provide a protective layer between the road surface and the tires of passing vehicles, which would otherwise damage the road surface by "plucking out" the bitumen-coated aggregate from the road surface.