The easiest way to get to the shop is through the city then into town where it increases to 40mph. On the way home it never fails. Some idiot doing 30 in the 40... and, you guessed it, when it slows down to 30 in the city they slow down to 20... I always have to ask: if you can drive 30 in the 40, why can't you drive 30 in the 30?