A driving line is a dynamically-generated line that appears overlayed on a race track, usually found in simulation racers or racing games that incorporate simulation elements. These lines can vary in colour, size, and shape, but generally they plot the most ideal route that a driver can take on a course. The colour of the line usually ranges from green to yellow to red, indicating at what speed the player is driving relative to the ideal speed as determined by the game. Driving lives frequently appear green if the player is driving at the correct speed or red if the player is driving too fast.
Driving lines are commonly an attempt to make a game more accessible to less experienced players, encouraging them to, for example take corners tightly, bleed off speed in preparation for a special manoeuvre, or gain speed on a straightaway. The driving line can be used in combination with other player assists, such as auto braking or assisted turning to reduce difficulty, potentially broadening the audience for more technical racing games.