Speedraser

Miraculix,

Driving on the shoulder is something that you're never supposed to do, as Mark said. Passing on the shoulder to get around cars stuck in traffic is like cutting in line, jumping the queue, etc. It's extremely obnoxious, and potentially dangerous.

Rennphile

You have to watch out for debris on the shoulder too.

TomF

In Washington, we have a really serious problem with shoulder and right-lane passing. (Although not nearly as bad as LA.) My friend who is a Washington State Patrol Officer was telling me that they call the shoulder and the striped-off area where lanes merge onto a highway the "gore zone." He says that the number of people killed or seriously injured trying to shave 30 seconds off their commute is appalling. These areas are for emergencies only, and only a fool would drive in them.