I've started with a 2x1 residential lot (with a sim living in), I've built a small house and placed a driveway. Then, I've expanded the lot across the road, to a 2x3 size (including the road).
I've entered again the lot, and finished building the house across the road: here is a snapshot in neighborhood view.
(The yellow car is a self-moving neighborhood car, while the white one is an owned car, parked in the driveway).
Soon I've noticed that both the pedestrian portals and the car portal (at least for the NPC cars) have been displaced:
Another thing that I've noticed is that now, when I pick the driveway to move it aroud, it automatically turns at 90°, and obviously it is not possible to place it down any more:
I'm aware that the "expand across the road" feature is still at an early stage, and the results can be odd; so, don't consider this as a bug report, but just as an oddity I wanted to share with the other users.