Princetown to the city centre of Plymouth is 15 miles. If the entire way was 20mph then it would be 45 minutes rather than the 30 minutes if it was 30mph. But t

Princetown to the city centre of Plymouth is 15 miles. If the entire way was 20mph then it would be 45 minutes rather than the 30 minutes if it was 30mph. But that's under ideal conditions where you're driving at a constant speed from point to point. In the real world I bet much of that difference would be eaten away by junctions and other traffic etc. as you hit the outskirts of Plymouth. The hyperbole of "severely isolated" really does your argument no favours.