Despite the fact that there is little or no evidence supporting its effectiveness, about 40 percent of license suspensions are for reasons unrelated to bad driving.

In the 1980s, Congress authorized license suspension for past-due child support and certain drug offenses. State governments soon followed suit. Today, drug offenses, past-due child support, unpaid traffic tickets and various juvenile offenses lead the list of social drivers' license suspensions.

Despite anecdotal evidence of success - drivers' license suspension is considered by some to be a legal form of arm-twisting - about 75 percent of motorists whose license is suspended or revoked continue driving. As one former judge noted, you don't need a license to drive. You only need a car.

Driving with a revoked, suspended or otherwise invalid license is like driving with a time bomb in the front seat, but the bomb does not have a visible clock. Millions of drivers are pulled over every year, and it is only a matter of time before your taillight burns out, your registration expires, or you roll through a stop sign when you think there is no one around.

California, like most jurisdictions, has a points system. 4 points in a period of 12 months, 6 points in a period of 24 months, or 8 points in a period of 36 months triggers a notice of suspension. After a hearing the state can take your license away for up to a year, in some cases. If you received an out-of state ticket, California assigns the conviction a comparable point total, so that Nevada speeding ticket appears on your record in Lamont and Shafter.