Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. High Quality Content by WIKIPEDIA articles! In snowy conditions, transportation authorities may require snow chains to be fitted on vehicles. This can apply to all vehicles, or those that lack certain motive combinations such as four-wheel drive and/or specific classifications of tires. Local requirements may be enforced at checkpoints. Snow chains should always be fitted to one or more drive axles of a vehicle, with varying requirements for dual-tire or multi-driven-axle vehicles that range from 'one pair of tires on a driven axle' to 'all tires on all driven axles' being required to have snow chains fitted when conditions and/or signage require it.