Krav Maga is very effective but it might be easier to find a decent MMA or Muay Thai instructor as there are loads around these days. I trained pretty hard at MMA for a couple of years, I was decent at it, but my preferred tactic is still to leg it.
I got followed from a bank machine a couple of years back, it turned into a footrace. I realised there was a police station nearby but my pursuers were between me and the cop shop. I doubled back round a parked car and after two lethal sidesteps made good my escape, back the way I'd come. The copper on the gates was pissing himself when I told him about it.