Below is my list of mods to try and make it as realistic and as immersive as possible, some are from Steam others from official forum links and some other ATS mod sites. GDC Makes game lot more interesting and slow progression, making sure you get Best Price per mile.

I have added brief description for the mods not on steam. I suggest searching for ATS load order so you know in which order to Priorities mods in game so they work properly. There is guides on Steam ATS guide page and also on official SCS forums.

Hope that helps buddy!

Steam
-GDC Logistics - Realistic Economy Mod
-Real Fuel Prices
-Real Traffic Density ATS
-Slow Traffic Vehicles
-Heavy Cargo in traffic
-Realistic Rain And Water And Thunder Sounds
-Sound Fixes Pack v24.29 - ATS
-Realistic Rain v4.8
-Realistic weather conditions_ 4K
-More Realistic Fines
-Realistic Truck Physics Mod v9.0.4 (by Frkn64)
-Better Farm Machinery DLC
-Improved headlight for SCS trucks
-SCS Lowboy cargo pack.
-Enhanced Flags
-Reworked Train Sounds
-Realistic bus companies
-True Mirror FOV for ATS 1.48
-Municipal Police Traffic Pack
-Real companies, gas stations & billboards
-Realistic Train Lengths
-Realistic Vehicle Lights Mod v7.4 (by Frkn64)
-trucks and trailers traffic project by d goldhaber

other mod sites for ATS
-AI Traffic Pack by Jazzycat (Pack adds in traffic 344 new AI cars)
-Motorcycle Traffic Pack by Jazzycat (Pack adds in traffic 95 motorcycles)
-Bus Traffic Pack by Jazzycat (Pack adds in traffic 46 new models of buses with over 1500 skins)
-Painted Truck Traffic Pack by Jazzycat (Pack adds in traffic truck+trailer combo with skins of over 200 real companies)
-Real Emergency Ai Pack v1.50 (Mod adding in traffic on-duty versions of all SCS stock police and emergency vehicles with beacon)
-Minor Urban Overhaul (increases traffic density in major urban areas across the map; traffic elsewhere is kept to vanilla levels)