Streetwalkers generally congregate in areas where there is adequate traffic, at the boundaries of police jurisdictions. For example, near an airport at the edge of the city limits. This way they can hope to spot undercover police, who might be constrained from conducting arrests outside the boundary. Up until 2018, with the Stop Enabling Sex Traffickers Act, there was a website for whoremongers to trade information on where the sex workers might be found.
The Stop Enabling Sex Traffickers Act has forced more sex workers onto the streets, since advertising on the internet is now more difficult.