It was icy and cold morning in Michigan when Mr. Busdriver Bob arrived to work. When he got into his bus he remembered Mr. Boss having told him yesterday to first pick up some students 5 miles north. Despite having lost his compass and having a poor sense of direction, Bob deduced his bus was facing north. How did he know? P.S. Sorry for my bad artistic skills!
I assume it's as simple as it looks.
The ice is melted on the east side of the bus because the sun rises in the east so it was likely to start melting there first.
May be because of: 1. lake effect, wind usually blows from north to north west/east 2. Or, birds migrating from north to south Both giving him some sense of direction
Because Bob dropped the kids off the previous day, drove home in a straight line, turned the bus 180 degrees and parked up.