When people talk about "Van Buren" in this sense, they are usually referring to the stretch of Van Buren St. east of Central Ave. before the road becomes Mill Ave. at Papago Park.
The nature of the area is made more obvious by the overabundance of cheap motels. Most residents of the Valley of the Sun as well as many other Arizona residents know of the reputation of the street.
It's also commonly used in jokes.
Jake: Down on Van Buren, right?
Wanda: No, that's my night job.
Jessica: You're pretty ugly
Jose: That's not your mom was saying last night at Van Buren.
Maria: My new house is on Van Buren.
Justine: Oh, neat, now you can visit your mom while she's at work!