They are also a deterrent to reckless behaviour behind the wheel. Any time I've ever gotten a ticket or pulled over and gotten a warning I've made a concious effort to avoid that behaviour again. I'd guess almost all are the same way. In any area where a particular violation is recurring, when the police conduct an enforcement campaign or program the particular violations will cease - at least for a while. Speaking for me personally, I'd like to see more enforcement in some areas, especially school zones.
It's a proven fact that people driving in a manner deemed appropriate by traffic experts, for the current conditions and locality, (speed, lights, behaviour and etc.) have fewer insurance claims. Also, the claims they do have are lower in cost, plus less are fatalities. While some will willingly drive correctly, the way to make sure the rest of us drive the way we are supposed to is traffic enforcement. Insurance also offer discounts to safe drivers. This is a monetary offset to the penalties you mention. Wonder how many billions the discounts add up to.
I do agree with you that many tickets are written for the wrong reasons and cannot be substantiated by any logic or law, unless it's skewed. I don't have any facts to offer but, I'd guess the number is a very small percentage of all tickets written. davidj92