Shuttle (2008)

It's after midnight when Mel and Jules, two young women, return to LA from holidays in Mexico; they jump in a shuttle to head downtown. The other passengers are a nervous accountant and two frat boys, one who's been hitting on Jules. They're soon on unfamiliar, deserted streets - to avoid a traffic jam, says the driver - then things go from bad to worse. What's going on and where are they headed? Guns, knives, chains, a tattoo, and medication play in the resolution.