Does traffic law require you be warned on how you might be trapped?

Background: I blew thru one of those red lights on a freeway on-ramp, the ones they use in So-California during rush hour to keep freeways moving quickly. There was nobody in front of me, nobody behind me, and the freeway was moving around 30mph, so while I did break the law, it was like farting in the wind... no harm, no foul and no affect whatseoever on people, property or traffic. I didn't argue with the cop at all, but he got me thinking when he read me his riot act about "public safety" and how "red lights are so important", this got me thinking... he was sat 1/4 mile down the road watching this in his rear-view using a hidden "cheaters light".

This cheaters light serves no other purpose other than to allow a cop to sit down the road, out of sight, and write tickets after the fact... and so I got a little pissed about the "concern for public safety" crap seeing as if he had such a concern, one would think he would use his presence to prevent the infraction to begin with.... I started thinking maybe he used this "public safety" banter as a way to make himself feel better about doing what is essentially a chicken-**** job of writing tickets for no real crime. It seemed to me that these on-ramp lights are for abating traffic congestion during rush hour and not for letting little old ladies cross the freeway...

So my question then:
Given that the situation with the "cheater light" and the cop using it was something of a trap, is there ANY legal concept or requirement that the city or the police must warn you about how they intend to observe you breaking the law? Traffic cameras at intersections have huge signs and are pointed out. Before they can use radar guns to get you, a survey has to be done at the road in question. Aircraft patrols have signs on the freeway warning that they are being used to observe speeders. Is there some legal basis that there should be requirements that the public be warned about these "cheater lights" since they are an "after the fact" tool?

Yeah I know Im splitting hairs on a technicality here... I'll pay the ticket regardless, but the legal argument has me thinking... anyone with a legal take on this one?

I didn't appreciate the moron comment. This was not like going thru an intersection red light, there was no cross traffic and I was moving slower than the traffic on the freeway. If you have never broken a traffic law, my hat is off to you and I know a cop who would love to sit with you and talk about how to make the world safer by hiding in trees and writing tickets. If you are like every other human who has ever driven a car, and you have broken a traffic law at some point in your life, then I say to you.. welcome to the real world... and I won't even call you a moron for doing it.

"is there ANY legal concept or requirement that the city or the police must warn you about how they intend to observe you breaking the law?" - None what so ever.

No, there is no law requiring that the city or the police must warn you about how they intend to observe you breaking the law.

It's not a "cheater light" It lets them safely observe cars and the metering lights. How else could they enforce them?

Your probably thinking of entrapment. This is not a case. The aircraft speeder signs are to get you to think about your speed they do not have to warn you. You blow through a red light I want you ticketed. Lets see 30 mph traffic, rush hour, you couldn't take a 15 sec stop till your light turned green pay the fine and donate to a victims group you moron.

I don't see how you would consider this a trap. You know its a red light and you went through the light and got caught. I don't think it really matters how the police observe you doing this rather they hide behind a sign a tree what ever the case the warning given to you by the city or police is simple red light stop, run the light because you think its a chicken sh-t light you get a ticket if caught. Bite the bullet pay the ticket your in the wrong regardless at however you look at it.