Normally one would not really like to be that close to a bison. Even though they look harmless, the can be quite dangerous. After all, they are still wild animals.
However sometimes they seem to seek the neighborhood of people. At least it looks like that, when they travel the streets or make a break at a picnic area. From within the safety of the car – I guess also the bison fill a bit safer if people stay in the cars – one may have the chance to be as closes as a few meters to them.