or decide on a scale and model the car and the road to the same scale.
110 mph = 49.1744 metres per second
so if you say 1 metre = 1 maya unit then your car will have to travel 49 units in 24 frames (assuming you are using film settings) or 25 frames if you are animating to tv standards.
so lets assume you are working at 25fps, say your animation is 210 seconds long or 5250 frames. and assuming you want your car to be in shot for the duration of the anim. you will need to have a road at least 257,250 units long.
might be a bit a bit too long
so adjust your scale, or consider using more than 1 camera. (which would make it more interesting) if you have a few cameras you could work in multiple scenes. also 5250 frames is a lot of rendering on a home pc!
this would have taken 3 years to render on 1 machine
it was about 1500 frames.
more elements in this tho, so not really a good comparison