The short-term solution to staying safe is to pray before you leave your house and to thank Hashem when you arrive at your destination safely. Learn as quickly as you can some basics in self-defense. A small but very effective pepper spray canister is also a good idea to have with you. In the long-term, teshuva and extreme care in observing the mitzvoth of man and fellow man will uproot terrorism altogether. Meanwhile, smile and don't fear - Hashem is with you.