Use the bus & train schedules to minimize the length of time waiting.
Plan your route to use the busiest, best-lighted stop possible, both to get on and off a bus or train stop. If you must wait, stay near the attendant's stand or in the best-lighted area available.
Be sure to have your fare out and ready before you leave home, office, or store.
If few people are on the bus or train, sit near the driver, or large groups of people.
Keep your purse, shopping bag, backpack, packages, etc., in your lap, on your arm, or between your feet -- not by themselves on an empty seat.
Don't let yourself doze off, it can make you an easy target.
If someone is bothering you on the bus or train, tell the driver/operator, or call 911 with a cell phone.
If you feel uneasy about getting off at your usual stop, stay on the bus or train until the next stop.