im guessing it may be and old computer?
try opening command prompt on windows or terminal in mac --
in the directory of the game try....
name_of_the_game_executable --video-driver GLES2
that should help.. immediatly after the track loads press esc. and switch off shadow, car lights, antialias and lower resolution.
hope that helps...
if you could give me your computer specs that will help me alot.
Thank you and sorry.