A seat attachment system for a mass transit vehicle including a rail, a fastener and a seat interface. The rail, which is adapted to be secured to a chassis of the mass transit vehicle, has a longitudinal T-slot adapted to receive the fastener. The rail has two non-parallel sets of corrugations on its external face. The seat interface, which is adapted to be mounted to a seat frame, is also provided with two non-parallel sets of corrugations whose angle matches that of the sets of corrugations on the rail. The sets of corrugations are adapted to cooperate and interlock in pairs so as to respectively locate the seat interface, and thereby a seat to which it is attached, vertically and horizontally upon the fastener being tightened.

A seat attachment system for a mass transit vehicle including a rail, a fastener and a seat interface. The rail, which is adapted to be secured to a chassis of the mass transit vehicle, has a longitudinal T-slot adapted to receive the fastener. The rail has two non-parallel sets of corrugations on its external face. The seat interface, which is adapted to be mounted to a seat frame, is also provided with two non-parallel sets of corrugations whose angle matches that of the sets of corrugations on the rail. The sets of corrugations are adapted to cooperate and interlock in pairs so as to respectively locate the seat interface, and thereby a seat to which it is attached, vertically and horizontally upon the fastener being tightened.

The invention relates to a public transport vehicle comprising at least one unit for the flexible transport of passengers and/or freight. According to the invention at least one outer side wall of the unit has multiple adjacent doors, that also form the outer side wall of the vehicle along the length of the vehicle, where when the unit is used for freight transport all doors can open to provide a wide entry opening for loading and unloading freight and when used for passenger transport one or more of the doors remain permanently closed and at least one door can be opened. The inventive vehicle uses a complete outer side wall of the unit as entry and exit possibility. When the unit is meant for transporting freight, all doors in the side wall can open to provide an opening as wide as the length of a unit. The whole space of the unit is than accessible for freight. When using the unit for transporting passengers it is important for safety reasons to keep the doors close to passenger seats permanently closed and locked. At least one door of the unit that is not close to the passenger seats should be able to open to let passengers enter or exit the unit.