ProMods

https://www.youtube.com/watch?v=qe2XrbP64uI

Does somebody know a mod just like this with crazy amount of cars and trucks or can explain me how to make my own one with traffic_data.sii

Just change these two lines as required.

# max_vehicle_count: 50 # Total AI vehicle count limit (including trucks)
# max_truck_count: 4 # AI truck count limit

Remember to remove the two '#' that I have made red.

Personally I use 180 & 60. The video example you posted would have it MUCH higher than that.

Please also remember that the more AI traffic the more system resources your game will use. If you have issues with any stuttering or lag in Promods cities, then it'll be far, far worse with higher AI traffic numbers.

Also considering how much traffic there is on the road in that video, his cities will probably be near impossible to travel in due to traffic amount and poor AI when it comes to junctions.

I have enough issues at junctions and in some cities with my increased traffic. If you get impatient with traffic on junctions when there's only one or two vehicles in front of you. Imagine how bad it can be with 15+

I do enjoy having the extra traffic, but sometimes I am forced to use the "g_set_time" parameter to move time ahead one minute to clear traffic just so I can get out of companies if the traffic builds up. It's a double edged sword really.

where do we can find traffic_data_sii?

We can find traffic_data_sii in def / def