My understanding from reading the expat hardship pay rates and the reasons behind them (because we're researching our next job) is that is that yes, the number of traffic deaths are higher, but that's only partially an issue with scooters/bikes (some of which is mitigated by slower overall speeds and less large, heavy vehicles on the road -- more bike/bike collisions than say, bike/SUV) and partially an issue with a different standard of emergency services and immediate health care interventions (so you're more likely to die of something that you might survive in the US, just because it took longer to get to you, to get you to health care, and/or when you got there, there was less they could do.)