My cars are stopping and going and then stoppiong again. Anyone know why?

Probably because your system is struggling to draw the graphics. Try turning down some of the display settings and see if that helps.

You're probably overloading your system. Turn things down a bit (including traffic) until you see more fluid movement.Randall

I doubt that is it. I am getting frames in the 40 range with all my autogen turned off and NO OTHER TRAFFIC, but If I turn on more than about 20% road traffic they display this behavior also. I am thinking everyone sees this every now and then. It may be related to system resources and If that is the case than this sim has even more problems than I originally thought.Im running a P4 @3.6GHX, Radeon X800XL 256mb, and 1G of PC3200.Hornit

What aircraft are you flying?

I'm also getting the road traffic doing the "stopping and starting" behavior. I find that it happens whenever the sim is busy loading up textures in the background. It looks like road traffic takes a "back seat", so to speak, to other priorities. I find that when everthing finally has completed loading, then the road traffic flows smoothly without interruptions.Give it a try. Pause the sim, (because when you're moving, new textures have to be continually loaded) and wait a minute or so until everything is loaded. The cars and trucks will eventually be running smoothly without the stops and starts.