What’s the difference between a commuter rail, light rail, and heavy rail transit system? I’m having trouble figuring out how to categorize the different types of transit serving my project.

USGBC provided some guidance in January 2018 (via a LEED Coach request) to help clarify this question. For heavy and commuter rail stations, teams should use their best judgment in determining whether a rail system falls within these categories, since the terms aren’t defined in the Reference Guide. To help with this determination, keep the following in mind:

• Commuter rail typically includes one to two stops per city/town/suburb along a greater rail corridor. Commuter rail often operates on tracks located at ground/grade level. Well-known U.S. examples of commuter rail include Metro-North (New York/Connecticut) and Metra (Chicago).
• A transit system that has stops as frequent as every few blocks (like a subway line) qualifies as Light Rail.
• Note that regional rail (i.e. Amtrak) typically would not comply, as this type of transit often has a significant distance between stops, comparable with airline flights, and is not used for daily commuting. However, some project-specific circumstances may justify contributions from this type of rail transit.