When you have more than two AI vehicles, the game becomes extremely laggy. In this case, I was driving the D15 Dually and had two AI controlled Grand Marshalls set to chase the player. At the time of the screenshot, my GPU monitor was at 0% and my CPU meter was reading 42% or less on each core, and the game was running at roughly 1 fps. It's obvious 25 fps isn't correct, and the CPU monitor is about where it usually is, but typically my GPU meter reads 99% (dat bottleneck ). Pressing 'J' to disable physics drastically improves the framerate.