Gameconfig Installation path : Mods/Update/update.rpf/common/data/ back up your gameconfig then change whichever you want.
Multiplayer values meaning: Like 4x traffic means 4 times more vehicles spawn only your area(Ambient not all map).
Multiplayer values meaning: Like 4x traffic 4x peds means 4 times more vehicles and peds spawn only your area(Ambient not all map).