Unless the laws have been changed in recent years, lane spliting is not legal. It's not illegal. For many years the DMV hand books in CA, both for autos and motorcycles, stated it was legal for motorcycles to share a lane. In the early 2000s that info started to disapear from the hand books. When talking to various law inforcement officers over the years I was told that it was a judgement call on the part of the officer. Speed seem to be the main factor. To much speed could be translated to a unsafe lane change or eccesive lane change, depending on the conditions, and would get you a ticket.
Gotta call you on that, Doc. We don't need a law that says something--anything--is legal. The stuff that
isn't legal is the stuff the law addresses. If it's not prohibited (illegal), it's legal. Here's a section of a Wikipedia article on the topic. (Their links--not relevant. And by the way, we in America see things in the way the article ascribes to the English.)
Everything which is not forbidden is allowed is a
constitutional principle of
English law — an essential
freedom of the ordinary
citizen. The converse principle —
everything which is not allowed is forbidden — applies to public
authorities, whose actions are limited to the
powers explicitly granted to them by
law.
[1]
National traditions
The jocular saying is that, in
England, "everything which is not forbidden is allowed", while, in
Germany, the opposite applies, so "everything which is not allowed is forbidden". This may be extended to
France — "everything is allowed even if it is forbidden"
[2] — and
Russia where "everything is forbidden, even that which is expressly allowed".
[3] While in North Korea it is said that "everything that is not forbidden is compulsory"
[4]
It may be a minor point, but it's a question of how people look at something. Do we--here in California, where lane splitting is legal--want to tell the public that lane splitting
is in fact "legal?" Or do we want to tell them it is "not illegal?" All that does is confuse the issue, and as far as I'm concerned, at least dilutes the point, and probably casts more negative light on the whole issue of lane splitting.
The police can always exercise judgement and discretion, if a driver is being reckless, careless, or dangerous to himself or others.
By the way, I wondered about your comment about the language in the CA Drivers' Handbook, so I looked it up. The following excerpts on "Sharing the Road/Motorcycles" seem to apply:
"Follow these rules to respect the right-of-way and safely share the road with motorcyclists:
- Allow the motorcycle a full lane width. Although it is not illegal to share lanes with motorcycles, it is unsafe.
- Never try to pass a motorcycle in the same lane you are sharing with the motorcycle.
- Motorcycles may travel faster than traffic during congested road conditions and can legally travel in the unused space between two lines of moving or stationary vehicles; this is commonly called 'lane splitting.' "
That third bullet is the one that applies to the motorcycle--they "can legally travel. . ." The phrase "not illegal to share lanes with motorcycles" in the first bullet applies to car drivers "sharing the road with motorcycles." The only reason I can imagine why it would NOT be illegal for a car to share a lane with a motorcycle is to protect a car driver from inadvertently committing a violation when a motorcycle moves into
his lane. But the driver can not overtake and pass a motorcycle that is occupying a lane (like when filtering forward at a red light). That would be obviously unsafe, and a LEO seeing this would have no problem writing a ticket on that basis alone.