Depending on which express lane you're using, there are two ways you can enter and exit the express lanes: open access or limited access (or a mix of the two). In open access lanes, drivers can freely enter and exit the express lanes wherever they choose, just like today's high-occupancy vehicle (HOV) lanes (also called "carpool lanes") in the Bay Area. Limited access lanes have specific entry and exit points.
Currently, the SR-237 express lanes have certain parts with limited access, but have multiple locations to enter and exit.
The I-680 Sunol express lane is limited access but has multiple locations to enter and exit.
The I-680 Contra Costa express lanes are open access.
The I-580 and I-880 express lanes have some limited access sections but, for the most part, are open access.
Topic: FasTrak Basics