Speeding is not a criminal act. Even the states and cities and counties recognize this. That is why you have to appear in civil or municipal court and not a criminal court. The state is suing you, nothing more. What makes this whole charade even worse is that, technically, the judge ruling in the case is usually also a resident of whatever jurisdiction the court is located in. That means the judge is a party to the lawsuit, how is that even a fair trial?
Citing speeding laws as being for the public good is another fallacy. The reality is that most people don't excessively speed. People tend to drive a rather safe speed given road conditions. Despite the fact that most speed traps occur in areas where 30,000+ cars travel that particular road daily, most people still drive slow through residential neighborhoods. The reason is not because of posted speed limits, it's because the roads are generally narrower, not striped, have cars on both sides, a higher probability of pedestrian traffic, etc. Put those same people on a road that has three lanes on each side going the same direction, with a median separating directions of travel, with a developed sidewalk, and asphalt in pretty good shape and you are likely to see speeds above posted by the majority of the drivers.
The other fallacy I see on here is how many people tell you that "speed kills". This is even misconstrued by governments. The NHTSA will tell you that speed was a factor in a majority of accidents. That statement does not equal "speeding was a factor". People going to slow for conditions causes an equal number of accidents. Slow drivers cause people to change lanes more often, an act that requires taking your eyes off the road and directing them to the mirrors and even removing a hand off the steering wheel to the turn indicator. The safest speed is not the posted speed. The safest speed is that speed at which 85% of the traffic on that section of road is traveling. If 85% of the drivers are going 55 in a posted 40 mph zone, then the safest speed is 55, not 40.
As far as the slippery slope argument that we would need to remove red lights and stop signs in a libertarian society, I don't buy that one bit. These devices are put in to aid in the flow of traffic. Most libertarians would agree that anything that leads to increases in efficiency are a good idea. Traffic lights were created by the private sector, not by government. That said, if you come to a red light and see that no one is coming from another direction, you should be free to proceed. However, you should also be aware that you will likely be the one the courts decide is at fault in an accident. I have run numerous red lights, mostly out in the middle of nowhere because some idiot who programmed the lights decided that a side street needs at least ten minutes of green light to clear all the cars out that aren't there.