HeavyCivilHelper Academy / Roadway design

What are the different types of bike separators? Class I–IV explained

California officially defines four classes of bikeways. Class I is a bike path, Class II is a striped bike lane, Class III is a shared bike route, and Class IV is a separated bikeway. Only Class IV requires physical separation from through motor-vehicle traffic.

Class I, II, III, and IV at a glance

• Class I — Bike path — A separate right-of-way for bicycle travel with motor-vehicle crossflow minimized. It may also serve pedestrians and other nonmotorized users.
• Class II — Bike lane — An exclusive or preferential on-street bicycle lane separated from traffic by striping. A painted buffer does not make it Class IV.
• Class III — Bike route — A signed route shared with motor vehicles, often used for network continuity on lower-speed and lower-volume streets.
• Class IV — Separated bikeway — An exclusive bikeway with vertical objects or vertical separation from through traffic, including curbs, posts, barriers, parking, or grade separation.