..and is a good tactic.
Not to be critical of anyone who does it, legally or not, but what makes it a good tactic?
1- It helps relieve traffic congestion, by increasing throughput of the same width road.
2- It saves gasoline.
3- An air cooled bike is only cooled while it is moving through an air mass.
4- It is an escape route from careless cage drivers.
5- It is an escape route from malicious cage drivers.
6- It saves a good deal of time and frustration to the betterment of personal health.
7- Police use this tactic to access assigned areas, as well as to improve general mobility.
In the 1989 Loma Prietta earthquake, I was at work when it occurred. (I was sitting on the throne in the men's room actually. Did you know that the stall doors automatically open during a shaker? What a thoughtfull design!)
Anyway, power went off, and when it became clear that it wasn't coming back on any time soon, I and most other people decided to go home. NO traffic lights were operational. And, of course, the streets were filled with vehicles trying to get home to assess damage. On an average day, I would save 10-15 minutes during my one way commute home if I used the Cb550 and employed occasional lane splitting. On this day, the entire distance was to be done in lane split mode, nearly door to door, and it took an extra 10-15 minutes for the standard route. (About the same as if I'd used the car on a normal commute day.) By contrast, other co-workers in cars who lived nearby to me, took an extra 2 hours for a nearly identical travel path, 7.5 miles.
Cheers,