And what about those doing 45mph, and don't see you in their mirrors? They keep going along at 45mph, just where you're trying to land. Or worse still, those who see you in their mirrors, and hit the brakes.....you've no airspeed left to go over them.....
On top fo this, have a look at the motorway the next time you're on it. I don't know what they are like in the UK, but here in Ireland, they are a mass of lights, road signs and amco barriers.......You'd have a narrow enough runway to get it right, first time, under pressure. The field would give you more room for mistakes.
dp