New found obsession with the road.

Help me! Our 6 month old puppy has a new found obsession with the road which is absolutely what we do not want. We are looking into an electric fencing system but would like opinions on what we should get. We only want him to be blocked in one direction and that’s the direction of the road, but would like him to have free range on the rest of the fenced in 40 acre property. Any suggestions, opinions, or ideas are greatly appreciated!