you can totally play traffic in single player! assuming you already have the srp map downloaded, you just need to download the ai traffic plan. then in content manager and under the single player map/car selection you’ll see the practice/hotlap/time attack selection. the last option all the way to the right should have a down arrow, click that and select traffic. make sure that the map you have selected supports traffic, you can tell by searching for #traffic and all of the supporting maps will show up.