If you happen to stump on a problem using this traffic with the new v1.2 there is a solution - don`t follow exactly the instructions for installing the LAC 1.2 and don`t delete the old v1.0. Instead just place the contents from the .7z "\MODS\LA Canyons 1.2 - Main\content\tracks\la_canyons\" into the track`s folder and replace the old files. That leaves the old one-way traffic almost intact (except the map goes blank). My layout was based on a "traffic_oneway_normal" and the model "layout_traffic_oneway_normal.kn5" is needed for loading the cars. So another way of making it work with v1.2 is to edit the "models_2way.ini" from this
to this
Also making the walls transparent trick is helpful if you edit the "..\content\tracks\la_canyons\2way\data\surfaces.ini"
After testing the new free v1.2 I find differences to be in favor of keeping the v1.0 as the new one has less vegetation and is missing the traffic.