slow game after traffic

hi all, im new to this game and my apologies if this is in the wrong place, im finding if i activate the traffic the game slows right down inc the menus, if i turn off traffic it makes no difference, has anyone got a fix for this? thanks

 

What are your specs

 

unsure on names but pc has
AMD Ryzen 3 3200G with Radeon Vega Graphics 3.60 GHz
nvidia with 4gb ram
32gb ram 1tb drive for storage
been fine in normal mode just bad with trraffic

 

well traffic means more cars so that's obviously going to slow down the game significantly on a lower end system.

 

thin is ive had traffic on before and it didnt affect the speed or anything, if i shut game off and restart its fine again