Why do you use a train to cross the Channel tunnel rather than driving dirrectly through in your car?

It is not possible to drive directly through the channel tunnel in a car, the rail tunnel cannot accommodate road travel. If you want to get your own vehicle to mainland Europe you need to use the separate road tunnel known as the Channel Tunnel which requires cars to be loaded onto train services to travel. However in most cases it will be simpler and faster to travel as a foot passenger on the rail service taking an electric locomotive train with carriages optimised for passenger carrying