Some California cities, such as Culver City, only ban commercial vehicles over 3 tons.

But Beverly Hills seems a little confused as to what's prohibited. Some of the signs in 90210 say the ban is on commercial vehicles, and the city's ordinance doesn't really clear things up. The article of the municipal code that contains the ban is titled "Commercial Vehicles," but the ordinance itself makes weight the only criterion: "No person shall operate any vehicle having a gross weight, including the vehicle and its load, of three (3) tons or more on any street in the city … " [my emphasis].

Traffic Sergeant Brad Cornelius of the Beverly Hills Police Department told me Beverly Hills cops do not pull over SUVs, because they are not commercial vehicles. But I think that interpretation is wrong. For one thing, the only definition of "commercial vehicle" in the Beverly Hills code comes in a different section of the same article. It is "a vehicle having a rated [payload] capacity in excess of one-half (1/2) ton." The Suburban's payload capacity, to take one example, is listed as 1,732 lbs., or well over half a ton.

Similarly, it's common for legal definitions of "commercial vehicle" to have nothing to do with whether a truck is used for business and everything to do with its weight. For instance, Arizona's definition of out-of-state commercial vehicles is simply that they weigh over 6,000 pounds and are operated in more than one jurisdiction.