People often drive over the allowed speed limit. Some do so accidentally – simply not realizing how fast they are traveling. Others do it knowingly, either not caring or thinking that a few miles per hour extra is not that big a problem.
The truth is that going too fast is a huge danger for those in the vehicle and other road users in the vicinity.
Increased collision force
The crash force that occurs when a vehicle hits something is calculated by the mass of the vehicle and the amount it decelerated in that crash. A car that was traveling at 45 mph in a 30 mph zone will have decelerated an extra 15 mph in the crash compared to a vehicle that was traveling at the limit and so the resultant crash force will be higher. That means more damage and injury likely occurred. Slowing down should make any crashes that occur less devastating.
More time to avoid a crash
You are driving along and see another vehicle turning across you. If you are traveling at 10 mph you have a far better chance of stopping in time than if you are traveling at 70 mph. You need time to notice the car, process it as a threat and react by braking.
Your car also needs more time to slow down when you travel fast. Even if you react just as quickly the car has more speed to lose.
If someone traveling too fast for the limit or road conditions injures you, they should expect that to be taken into account when awarding you compensation. You may need help to prove it though.