1) the 'road' is worn and unkempt, and there is the possibility of running into wildlife, but nothing too dangerous.

2) There's nothing along the road hindering his speed.

3) You can get to the gates, but they will not open. In fact, there seems to be some sort of force field barring any sort of entry, even if he attempts to climb the very high (think 20 ft +) walls.

4) The road is in a sorry state and a cart would be perilous unless the road was repaired somehow.