Dan, a reader sent this link to an interesting Slate piece on the fact that big SUVs (anything over 6,000 pounds) are illegal on most of California’s residential streets (though no one’s enforcing it).

The SDOT website implies that Seattle’s load limit on non-arterial streets is 10,000 pounds of gross weight (with a few exceptions). That might exclude the Hummer H1, but not much else. Damn.