I have always advocated for bicycling against traffic, with the reasoning being you can see the cars coming toward you. When you ride with traffic, which is technically the correct way, you can't see approaching vehicles. I always feel like a sitting..or riding...duck.
Now, a new study in Finland finds walking and running "against" traffic, is the safest way.
It's a showdown that plays out every day: Two runners approach each other on the shoulder, one running with traffic and the other against. Who is running in the correct direction? If there's a sidewalk, the law says that's where they should be.