2d road sprite's size?

Can you describe your game in a bit more detail? Is it top-down? Side-scrolling? Pseudo-3D? What kind of shapes will your roads take? What do you mean by "how high should the road be"?

Thanks for replying,
Well my game is like the old road fighter.
what I mean by how high the road should be...is the height. if I simply use one piece of image. how high should it be?

Ah, gotcha :-)

Usually the way this is done is to have a single sprite that you repeatedly draw in a vertical stack. So the sprite would be about as tall as one "stripe" on the road plus one "blank space" between stripes, if that makes sense. Then you just draw that several times, each copy going below the one above it, and you have the complete screen.

Thank you I got it all