Let's say you are in London and you need to be in Birmingham (unlikely, I know).
The benefit of travel is that you can do it.
The best way to be safe is to wear a full deep sea divers outfit (unless you happen to work for NASA; they might lend you a space suit).
Wear a body-belt for your money and passport, and carry a rape-alarm. The noise it makes would scare off anybody. You'll be safe, but deaf.
And stay away from Afghanistan.