Sure, here's an example of a simple car racing game implemented as a single HTML file using JavaScript:
Car Racing Game
In this game, a brown-colored "car" (represented by a `div` element with a specified background color) will move on a white background road (the `game-area` div). You can control the car's movement by pressing the right and left arrow keys.
Please note that this is a basic example to demonstrate the concept of a car racing game using JavaScript within a single HTML file. You can further enhance it with additional features and graphics based on your requirements and preferences.