Driving MR license trucks in the snow can be quite challenging, but there are certain advantages to driving a large truck in the snow or mud as well. The fact that these vehicles put more weight onto the axles is an advantage in slippery road conditions. However, if they lose traction then using the engine brake or the retarder may only make the situation worse and could leading jackknifing.
Jackknifing is more likely to occur on ice than on snow, especially if the vehicle is towing a trailer. In extreme cases, the trailer can push the vehicle from behind until the entire unit spins around and is facing in the opposite direction. The vehicle can become stuck and block lanes of the road, causing congestion and accidents. Many trucks are fitted with anti jackknife devices to try to avoid this outcome.