Arent there typically easememt laws which prevent someone from locking themselves out of access to their own land?
Not here in Maine for raw land./undeveloped land.
You need road frontage, a deeded right of way, deeded easement .... something in order to get a building permit. In my case my 14ac lot was the last remaining lot of an old subdivision, marked as future expansion on the old plan. The existing road ended at my lot. I bought the 52ac, paid surveyors and engineers to design a new subdivision, got town and state approval to proceed and extended the road through the combined parcels so each new house lot had road frontage. Violá!