Aantono thanks for suggestion. I’ll try to update it

Runom - it should be possible - look at the examples of one way bus and gs stations, how that’s scripted. The same thing should apply here.

As an alternative, maybe remove collision and the underpass roads entirely and this will allow the overpass to be placed over an existing road setup without collision issues.

Paganea sadly no. Unfortunately, i couldn’t script that. If somebody has an idea how to do it, i’ll update this

Is it possible to have a road above the other two inside one placable building?

Now that is an innovative use of these elements :D

If I link 1-way roads to this, both two roads work as 1-way fully?

Very smart