Definition: Single or Double Sided

A single sided car is one with doors on only one (normally in North America the right hand) side. This means that all passenger platforms need to be on that side only. A double sided car is one with doors on both sides, configured so that the operator can operate doors on both sides of the car from the front. Double sided cars allow lines to be designed with passenger platforms on either side of the track. However, if passengers will be boarding from either side, then the car needs to be configured so that passengers from both sides will pass the farebox at the operator's or conductor's position.

Double ended cars normally have doors on both sides of the car and controls often are configured so that the operator can operate doors on both sides. It is less common for single end cars to have doors on both sides, but in some cases have doors on both sides. For example, PCC cars for Boston (such as the one pictured below) were unusual in that they were single end but did have a door on the left hand side to allow double sided operation, made necessary by the layout of some Boston subway stations which had platforms on the left side only.

This Boston PCC car is single ended and double sided, as it has a door on the left side..