ProMods

What does the 'No lane change' traffic rule actually do?

I tried:

• Using traffic areas in the map editor
• Creating a new traffic lane and applying it to a road

And it seems to make no difference what so ever. What I'm looking for is a one way two lane sliproad where the AI won't change lane immediately (especially trucks) so they can actually go in a different direction. As far as I can tell, SCS haven't used this rule anywhere either when searching for it using the Find non-visual items.

On a sidenote, what does the 'Crossroad Area' tickbox do?