Speed blindness is when you cannot accurately judge your own speed.

It is usually underestimated. Speed blindness typically occurs when maintaining a steady speed on a major road or in a tunnel. To avoid speed blindness, you can monitor your speedometer. Then you will always know how fast you are driving. Speed blindness might cause you to:

misjudge your stopping distance and brake too late or too lightly in a hazardous situation

exiting the road at too high speeds

driving too closely to the car ahead of you driving too closely to the car ahead of you