You need to establish what the rights and obligations are within your Land Title. If there aren't any, you can do what you like, legally.
The typical arrangement where this is set-up on a new housing estate is that the land is physically partitioned down the middle (in terms of ownership) but that there is a right for your neighbour to pass/repass on your bit (and vica versa). But often neither of you can PARK permanently on the shared bits and nothing else can be constructed on it - like a fence. The obligations may include a clause that any maintenance required on the whole shared area is a shared cost.
In the Land Title there would then be reference to a title plan (map) that shows in coloured hatching markings the area of land impacted by the above.