How much over the speed limit is acceptable on national highways?

[VanPeyton]

National highways do not allow speeding, and any speeding on national highways is considered a traffic violation. Speeding reduces the driver's ability to judge speed: When driving at high speeds, drivers not only misjudge the speed of their own vehicle but also underestimate the speed of pedestrians, bicycles, and other vehicles. This can lead to misjudging the speed and distance of oncoming vehicles when overtaking, as well as underestimating the distance required to overtake the vehicle ahead. Often, reactions are delayed, increasing the risk of collisions or side-swipe accidents. Speeding decreases the driver's reaction time: When speeding, the frequency of overtaking and encountering oncoming traffic increases, reducing the distance between vehicles. The driver is overwhelmed by the rapid changes in the external environment, consuming significant mental and physical energy. Frequent shifts in attention can lead to fatigue and, over time, drowsiness, greatly increasing the likelihood of accidents.