Today is very icy and cold morning in the Newcastle.
Mr. Shearer, an office bus driver arrived to pick the employees from the last stop. Shearer suddenly remembers that he needs to pick a newly joined 4miles to the north. Mr. Shearer lost his direction compass, a few minutes later Shearer is able to figure that he is moving in the correct direction i.e. north.
How did Shearer know that he is moving in the correct direction?