In several of the replies, I've seen some bad assumptions and incomplete information. Rather that add replies to all of them (I'm lazy ;) I'll just comment generally and people can draw there own conclusions.
First, the theory that speeding on open and dry roads is not more dangerous than doing the speed limit. A quick check of the actual distances to stop shows (these numbers include an adjustment for reaction times) at 60 MPH you need 312 ft, at 70 you need 399, at 80 you need 496, etc. In other words, you need to see and react to problems in the road ahead nearly 100 ft further for each 10 MPH at highway speeds. Or you can expect to stop shortly after hitting that stalled car ahead of you. Doesn't matter how well you know the road, it's how far ahead can you effectively see and judge closure rates. A study by the NHTSA (1989) showed that fatal accidents increased by 21% when the speed limit was raised from 55 to 65. I thinks it's a safe guess that at least some of these fatalities "knew the roads like the back of their hand".
In the city, if you hit a pedestrian at 20 MPH there is a 5% chance of killing him/her. At 30 MPH you now have a 45% shot at causing death (European Transport Safety Council, 1995). How sure are you that the kid you see ahead will not step into the road in front of you when you're speeding?
The roads are generally built for average vehicles at specific speeds (at least the newer North American ones). That means, as an example, a mid-sized car will generate a specific maximum lateral force when doing the posted speed in a turn or on a freeway on-ramp. If your car is heavier, is a truck, has bad suspension, etc, you'll need to slow down to remain safe, although there is a safety factor built into the maximum lateral force acceptable for a curve at the posted speed. The lane widths, shoulders, sight distances, guard-rail placements etc are all based on specific vehicle sizes doing specific speeds. That's why trucks are still limited to 55 MPH on many of the roads where the car limit is 65 MPH. If you get too far outside what they've designed for the risks go up substantially.
Lastly, is there any benefit to speeding? Well for a 30 mile trip, it will take you 30 minutes at 60 MPH. If you do the same trip at 75 MPH you'll save a whopping 6 minutes ;) Unless you get pulled over for speeding, in which case it will take about 10 - 20 minutes longer depending on the cop. In general, the shorter the distance to be travelled, the more of a speed increase you need for the same amount of time differential. To save that same 6 minutes on a 15 mile trip you'll need to up your speed from 60 to 100 MPH. Turns out, the speeding tickets are just a tax on peole who are in a hurry but never did the math ;) If you're not speeding, photo radar is not going to be an issue.
I'm not going to even try for aggressive driving, sleepy or impaired drivers or running amber or red lights and other such stupid people tricks. I hope we can all recognize that there is no way to justify these types of behaviour unless someone feels there is a specific right to injure, maim and kill with your car.
Even if you win the rat race, you're still a rat.