Even just TWO PEOPLE! Walking abreast. The concept of going single file for all of FIVE seconds so the oncoming person doesn't have to walk on the grass seems to elude most people. I've taken to firmly standing my ground. They can inconvenience themselves, I'm not moving.

And what's up with walking on the left side instead of the right? Are they afraid someone is going to snatch them into their car if they walk on the correct side?