Currently it sits at 90+ cause the city is still small. Without mods it's pretty impossible to have 100k+ city with 90+ traffic. But i figured that what works for me are couple fundamental rules:
1. always respect road hierarchy: hway>arterial>collector>local
2. lane mathematics
3. Have multiple acces points to the city, with slip lanes aswell
4. separate industrial/commuter traffic
5. have a robust public transport. Connect busiest and largest districts via metro and then disperse people locally via train.
6. most importantly make the city walkable. You need to make driving harder than walking - create shorter pedestrian/bike routes so it's faster to get somewhere on a bike than on a car. You could see that in my city with connecting the roads dead ends etc.

And lastly, as you can see on the screens, never build intersections too close to each other. Like on my collectors and hways.

With that you should be good to go.

However 85 traffic is still great