Passenger rolling stock often operates with a softer suspension than used in freight cars, in order to obtain good ride quality. In order to maximize seating, interior width forces exterior width to approach Plate C freight car dimensions. Close clearance to platforms is an important safety consideration for passenger entrance and egress. The associated rolling stock and platform designs need to be considered as clearance issues, especially in mixed passenger and freight traffic operations. Some passenger railroads that operate self-propelled cars use a third rail for power collection, which presents a clearance constraint on curves, particularly for the undercar equipment that is common on these cars. Maximum height at center of cars and locomotives is constrained by catenary clearance in some operations.
Clearance considerations for passenger rolling stock on new and/or existing properties are covered using a general approach. Examples are presented which illustrate some of the factors that need to be considered in clearance investigations.