Remind me not to get into your car!! Haha only joking, I speed quite alot as well, and so does most of the drivers out there on the road from all ages. Even when a particular road is a 30mph limit road, if it is safe and long to go faster, people will speed. And if you do not go as fast as everyone else and holding up everyone else behind you for obeying the rules, they will dangerously overtake you and honk their horn. This was what it was like for me when I passed my drivers test and drove independently for the first time. Without the learners plate, people will pressure you to speed by driving really close to you, flashing their headlights and tailgating.
Another reason why people speed on the road is because it is easy to get around the safety cameras, simply just slow down to the legal speed, when you pass the camera, go back into speeding mode. People often gets a 'buzz' from driving very fast because of the surge of adrenaline and that can influence a person to blaze through roads with wheels set on fire.
Now for the statistics of speeding. On average, 9 people are killed and 85 injured each day on the UK's roads. Without the speed cameras, around 100 more people would be killed each year. So yeah, speeding is bad, it is dangerous and very much illegal, though the majority of drivers often get away with speeding without any penalties or punishments what so ever.
Another issue is that some people who are charged for speeding are actually innocent. This can happen if 2 or more cars are flashed by the speed camera because one of them was speeding. Whoever is to be blamed for speeding is up to the authorities so the system far from perfect.
Here is the link to a story about a 21 year old driver who was charged for speeding while innocent, and won the court case by proving his innocence.
More information on speeding can be found on the links below: