I'm thinking more of a thriller. Like, a dad is stuck in traffic with his little kid in the backseat, steps out to talk to someone about what happened, and when he gets back, the child is missing. Police are stuck outside the mega-jam, and with time running out the dad would have to run around, asking people for help and trying to track down the kidnapper.

Or just add zombies and you get S2E1 of The Walking Dead. ;)