I asked an AI about Class IV Separated Bikeways

[Jim Baross]

In California, is a Class IV Separated Bikeway part of the roadway, or is such a bikeway adjacent to but not part of the roadway?

In California, a Class IV Separated Bikeway is considered an on-street facility that is adjacent to but not part of the vehicular roadway. The separation between the bikeway and the main vehicle traffic lane is a key defining feature.
How California law defines it
Adjacent to a roadway: According to the California Streets and Highways Code, a Class IV bikeway provides a right-of-way "designated exclusively for bicycle travel adjacent to a roadway and which are separated from vehicular traffic".
Excluded from the roadway: The California Vehicle Code defines a "roadway" as the portion of a highway "improved, designed, or ordinarily used for vehicular travel". The mandatory separation for Class IV bikeways means they are not part of the area used by vehicles.
Separation methods: The separation can include physical elements like flexible posts, inflexible barriers, curbs, planters, or on-street parking.
Different from other bikeways: This classification distinguishes it from a Class II bike lane, which is merely a stripe on the roadway and not physically separated from traffic.
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Are bicyclists required to use Class IV bikeways in California?
In California, is CVC 21208 applicable to Class IV Separated Bikeways?
No, California Vehicle Code (CVC) 21208 is not applicable to Class IV Separated Bikeways. The "bike lane" referred to in the law is a specific type of facility, and the physical separation of a Class IV bikeway places it outside the definition of a standard bike lane under CVC 21208.
This law, which applies to Class II bike lanes, requires bicyclists traveling slower than the normal speed of traffic to ride within the designated lane.
It is a mandatory-use law, with exceptions for situations like making a turn, passing, or avoiding road hazards.
Class IV Bikeway is a different type of facility
A Class IV Separated Bikeway is an on-street facility that provides a physical separation from the main roadway with elements like flexible posts, curbs, or planters.
This physical separation makes it a distinct type of bikeway, not a "bicycle lane" as defined by CVC 21208.
What this means for cyclists
Voluntary use: Bicyclists are not legally required to use a Class IV Separated Bikeway if one is available.
Right to the road: A cyclist can legally choose to ride in the general purpose traffic lane next to a Class IV bikeway.
Other applicable laws: Cyclists must still follow all other applicable traffic laws, but CVC 21208 does not apply to their choice of whether to use the adjacent Class IV bikeway. 

Jim Baross

[Alan Forkosh]

Enough with accepting AI for factual questions without referencing sources. Asking Jim’s question to Perplexity, I got this:

Formatted this way, I check the listed sources to confirm the accuracy of the statement and also explore the source beyond the answer given.

Alan Forkosh                    Oakland, CA
afor...@mac.com

https://al4kosh.com