green is acceleration, red is deceleration, and gray is average speed. km counting is in progress, you need to get to the very end and you will be protected for 1 km and you will start driving again.
In future updates after you get the mechanics done. Maybe add the off-road plane which if you drive on you'll be slower over time and has signs which randomly appear. When you hit them you lose. This might be better than having black void on the sides.