I recently ran a post about "building bridges" with people with whom you do not get along. The discussion it provoked was interesting, with several people showing up to effectively demonstrate why attempts at finding common ground and building bridges can fail. Yesterday, I had a similar experience when I commnted at The Blackboard. It might be my fault as I am told:

You might want to think about how hostile and petty your contributions sound from the get go.

I'll admit I can be hostile and petty at times. As such, I won't rule out the possibility that statement is accurate. People who care can judge for themselves how petty and hostile this comment is:

I happened to see this post and felt I needed to point something out. I get the analysis in this post is hypothetical, but I feel it is important to note Oregon doesnt require a car clear an intersection to avoid being given a ticket for running a red light. I dont know of any state which does. There may be some, but in the case of Oregon, you only run a red light if you enter the intersection after the light has already turned red.
I couldnt find Jarlstons analysis with a quick search so Im not sure what assumptions he used, but based on the formula this post provides for his analysis, it would appear he has made a non-trivial error. The W/v term should not be included in any analysis of yellow light timing in Oregon.
For what its worth, I tried searching for states where this scenario accurately describes the traffic laws. I couldnt find any. Someone else might be able to. If not, it would appear all red light cameras (in the United States, at least) are triggered only if a car has entered the intersection after a light turns red.
Incidentally, red light cameras generally have a small grace period between the light turning red and them starting to trigger. Ive found reports of them ranging from .1-.3 seconds. I dont know if thats worth including in ones analysis.

As well as the tone of the follow-up comment I posted 15 minutes later:

As a quick follow-up, I found this document providing detail on the analysis in question. I see I was mistaken to say that term shouldnt be included in timing of yellow lights. The reason Mat Jarlston includes that term is because it is relevant for safety purposes. You want vehicles in an intersection while on red to clear the intersection before the next green light comes on.
That just has nothing to do with running red lights. You only get a ticket for it if the light is red when you enter the intersection. If you cant safely stop at a yellow light, you shouldnt get a ticket for running a red light.

I don't think these comments exhibit a great deal of pettiness and hostility. Maybe readers will disagree. I'm not going to worry about that in this post. You see, I've become a bit fascinated by the subject matter discussed in those comments. Originally, I only spent a little time researching this topic. When I wrote those comments, I thought they'd just be taken as a minor point of interest that wouldn't go anywhere.

That wasn't the case. Because of how the discussion played out, I wound up spending quite a bit more time reading up on traffic lights. I even talked to a couple family members who are over for the holiday weekend about traffic lights in a casual discussion. What I came to realize is there is a lot of justified uncertainty and confusion about what traffic lights mean. Given that, today I'd like to discuss a simple question, "What does a yellow light mean?"
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