eCFR :: 49 CFR Part 37 -- Transportation Services for Individuals with Disabilities (ADA) https://www.ecfr.gov/current/title-49/subtitle-A/part-37#p-37.3(Rapid%20rail)

原文！＞＜；
"Rapid rail
means a subway-type transit vehicle railway operated on exclusive private rights of way with high level platform stations. Rapid rail also may operate on elevated or at grade level track separated from other traffic."