Cars are getting better and better at keeping us safe. Over time we should increase the speed a little bit every four to five years. As long as we are smart about going over the speed limit, we will be ok or even better. Hopefully with this technology we will be able to take turns at 300MPH. That be awesome.
I found myself losing concentration at slow speeds on both city roads and motorways. I agree that 30mph in the city centre is the right speed because of pedestrians and cyclists however on motorways, 70mph is just ridiculously slow and prone to let drivers look around and create unnecessary hazards for themselves and others. Cars nowadays are incredibly efficient and safe, speed limits have been the same for the last 50 years in the UK, yet cars are 5 times safer than they were back then.
Efficiency. If the car couldn't go faster than the speed limit because the engine wasn't capable then it would burn out much faster (optimal efficency for the type of engines used in cars is about half max speed which is why most cars go 120 mph max) you'll notice the engine straining around 100 mph even in new cars and that number gets lower through use. An engine designed with a max speed of 60 would shrink their effective life span enough to make them no longer worth the cost, and an automatic break that activates after a certain speed was ruled too dangerous because the driver wouldn't control it and might not notice before something bad happens if they're careless.
The faster you go the less you see, why is faster better, if you are in a hurry you will make mistakes, don't people want to see the world or are we all in a hurry to go no were. I guest lazy people don't want to wait, speed kills