California Vehicle Code (CVC) §21230 clearly states that it’s illegal to ride an e-scooter on a sidewalk.
There is, however, one exception to this rule. CVC §21235 notes that the operator of an e-scooter can legally ride on a sidewalk if they are leaving or entering an “adjacent property.” Besides this reason, it’s illegal to ride e-scooters on sidewalks, that includes Lime, Bird, Spin, Scoot, Lyft, Uber and Skip.
While on the subject of sidewalks, CVC §21235 (i) notes that e-scooter users should never leave an e-scooter lying on its side on a sidewalk. It’s also illegal to park an e-scooter on the sidewalk in any way that will disrupt pedestrian traffic.
Although sidewalks are banned, e-scooter users can ride on bike lanes, bikeways, and trails per CVC §21230. It’s also legal for e-scooter users to travel on streets provided the speed limit is under 25 mph. CVC §21235 prohibits e-scooter users from getting on highways if the e-scooter’s handlebars force the riders to put their hands higher than their shoulders.
Before riding on bike lanes, however, it’s important to double-check local laws. CVC §21230 says local governments can override the law that allows e-scooters access on bike lanes.
Furthermore, CVC §21229 states that when there is a Class II Bikeway on a road, e-scooter users should ride in this lane. The only times an e-scooter should get out of the Class II Bikeway are when there are vehicles or pedestrians in the lane, before turning left, to avoid debris, or when about to turn right.
Basically, a Class II bikeway is defined as a one-way bike lane on the side of a street or highway with a striped line barrier. To better understand bike lane classification, check out this PDF put together by Caltrans.