Whether you're new to running or a seasoned pro, the question of which side of the road do you run on is one that can be confusing. Especially for runners who often find themselves navigating busy city centers during rush hour, the answer can be an important factor in your safety.
Most runners, walkers, and cyclists follow local laws that require them to be visible when they're on a public pathway, sidewalk, or road. This means that it's generally safer to run on the right side of the road when possible, rather than running against traffic.
If you're running on a sidewalk, it's courteous to let pedestrians know that you're on their left or right by shouting "on your left" or "on your right!" at least 10-20 seconds before approaching them. This lets them know they have time to move out of the way and avoids any unpleasant interactions.
Driving: Drivers should be courteous to runners and walkers on roads, as well. They should yield to pedestrians at stop signs and give runners and walkers ample space when passing or reversing.
Those running on the road should also be aware of the need to take extra precautions around sharp bends. They should also watch for approaching vehicles, and be prepared to cross the road when it's safe to do so.