You do talk some rubbish - tiled and scaled road?
The background was done using a fixed perspective view of a road, wider than the screen and narrowing to the horizon, with solid lines for the road edges. Horizontal lines were copied from it, with some skipped or duplicated to make the road rise and fall, and shifted left or right to make the turns. No scaling, no tiles, and no big secret. And at the same time an alternating colour palette was applied to each line to make bands of colour run towards the player.
The novelty in Out Run was that it could render two roadways side-by-side, splitting them right down the middle should they overlap. That way it could draw a very narrow road, or widen it out into two carriageways or even fork off in two directions. The only time you see the true width of the road from the stock graphic is when you're going down one fork, before the road merges with the other half again.
Space Harrier and Hang-On used the same system (though with just one 'road'). The big difference in Space Harrier was that its starting image was a series of evenly spaced strips running to the horizon instead of just a single road. Then with the palette shifts applied you got the familiar gingham-shaded chequerboard.