It's a Bristol Omnibus map of the northern part of Somerset. Don't know the day, I guess 1960s or so.
Here's the front cover:
At least you could get refreshments, with the snack snack bars and the "temporary snack caravan" at Bristol. And its all under cover on a wet day - when no doubt the bus windows would have steamed up and you couldn't see anything anyway.
Heres the Bristol; Omnibus heading: