A group of characters are in a strange American city. Their car is locked in a compound, I think. They have to get across the city to safety. The phone boxes don’t work. They are followed by intimidating prowlers and gangs. The police can’t help and always seem to be busy. The feeling of the movie is quite claustrophobic. It’s like the Poseidon adventure but in a strange city. Been trying to find out the name of this movie for years!
Another guess, “Final Jeopardy” (1985)?