He would not go across fields as such as easy to loose your direction and depending on what crops were in them, but around the edges of them.
The Sea Wall goes along the edges of the fields.
This was wide and good terrain to cycle on. As several sources have shown. It was also an open area so there would be good vision.
Walking around the edges of fields would take too long and be too tiring.
Walking a more direct route across fields was not possible.
I have said this before.