Trees, particularly on roads, have hitboxes that are exponentially larger than iself. Dirt road in north Berezino in between Berezino and Khelm for instance, has a line of trees adjacent to the road, but the tree hitboxes overlap the dirt road. Also, driving in the woods, you will also hit many invisible blocks driving between trees even though it clearly shows you have clearance between them. This problem might also be contributed to the roots underground who's hitboxes are too large.

On foot, you walk right through these occlusion blocks. Vehicle, however, does not.