Light rail vehicles are built in a variety of designs and dimensions. In almost all cases, they are capable of being operated in coupled trains. Modern LRVs are generally much larger and heavier than their streetcar predecessors and can have axle loads just as large as, or even larger than, so-called "heavy rail" transit vehicles.
Light rail vehicles vary in the following design characteristics:
Unidirectional versus bi-directional
Non-articulated versus articulated and, for the latter, the location(s) and configuration of the articulation joints
100% high-floor versus partial low-floor (typically 70% or less) versus 100% low-floor
Overall size (width, length, and height)
Truck and axle positions
Weight and weight distribution
Suspension characteristics
Performance (acceleration, speed, and braking)
Wheel diameter and wheel contour
Wheel gauge
