The Broadway in the song is a street in Seattle's Capitol Hill district, a street on which the Mix-a-Lot Posse got lots of good grip from the 50 series tires.
The geography of the song is quite specific, going north up Rainier Valley on Rainier Avenue S., then east to "23rd and Jackson" (23rd Avenue S. and S. Jackson Street), a major intersection in Seattle's traditionally black Central District or "CD," then cruising east to Martin Luther King Jr. Way S. where "the set looks kinda dead" so "we need a new street," then by "23rd and Union" (23rd Avenue and E. Union Street, still in the CD, but northeast), and then to Broadway. "The college" is Seattle Central Community College near the south end of the Broadway commercial strip, from which they drive to Taco Bell at the north end, which "was closed" (a local joke, as that particular restaurant had a never-lit and wholly inaccurate "Open 24 Hours" sign built into the wall) so they "go back the other way" to Dick's Drive-In, a local fast food institution and, according to the song, "the place where the cool hang out."
There are two versions out there by Sir Mix-a-Lot: the "Radio Edit", which was played on air and the "Godzilla Remix Edit", which featured Godzilla's signature "roar" and a sample of the guitar riff from David Bowie's "Fame". The lyrics are slightly different between the two, most notably Mix-a-Lot references the "Gatorback" tires on his limo, instead of the "50-Series" in the radio edit and refers to the vehicle as "the Bistro" in the Godzilla version.