Question:  I have two new signal systems about 500’ apart and speed limit is 30mph.  I worried about there would be visibility conflict between these two signals.  So, in what situation the louvered signal head is required?

 Answer:  The issue with closely spaced intersections is that the driver wating at the stop bar of the first one might see a green at the second one and start driving, even when the closer signal display is still red.  The Caltrans traffic manual had a guideline to rest...


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