Flashing Yellow Arrow, Then a Dark Signal
6:20 p.m., dry and clear. You are first in the left-hand of two left-turn lanes at a large signalized intersection, stopped behind the limit line. The left-turn display is a flashing yellow arrow, and a sign reads LEFT TURN YIELD ON FLASHING YELLOW. Oncoming traffic is 500 ft away and closing at about 45 mph. A panel truck in the right-hand left-turn lane has crept slightly ahead of you, and its box partly blocks your view up the oncoming lanes. You intend to turn right at the next intersection, 300 m ahead, which is completely dark: no displays are lit on any approach, and a police officer standing in the middle is waving traffic through. That second intersection is one-way to one-way, and an upright sign there reads NO TURN ON RED 7 AM-9 AM AND 4 PM-6 PM. It is now 6:20 p.m.
1. The flashing yellow arrow is on. What exactly does it authorize, and should you take the gap as the panel truck moves off?
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A flashing yellow arrow is a permissive left turn: you may turn, but you must yield to oncoming traffic and to pedestrians crossing on your green. There is no protected right-of-way in it. The panel truck's movement is not evidence that a gap exists for you, because its box blocks your view up the oncoming lanes, and with two left-turn lanes a second oncoming vehicle can be hidden behind the first. Do the arithmetic anyway. 500 ft at roughly 66 ft/s is about 7.5 seconds to your limit line, and your own turn from a stop, from the inner lane, takes roughly 4 to 5 seconds to clear the opposing lane, plus perception and reaction. That leaves a thin margin on the first vehicle and none at all for a second you cannot see. Wait for a gap you can see all the way through, not one you infer from someone else's movement.
2. The next intersection's signal is completely dark. May you treat it as an all-way stop, and what does the officer change?
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A dark signal is a failed signal, and practice varies by jurisdiction: many require you to stop and yield as at a stop sign, others treat the intersection as uncontrolled and apply ordinary right-of-way rules, and some require a full stop only for traffic entering from a minor road. Because you cannot assume everyone will stop, treat the dark head as a stop sign on your approach: stop, then proceed only after confirming cross traffic is actually stopping. The officer's directions override signals, signs, and markings, and disobeying a directing officer is itself an offense. Make eye contact, follow the hand signals, and if a gesture is ambiguous, stay stopped and let the officer repeat it rather than guessing and rolling into a pedestrian or a crossing vehicle.
3. May you turn right on red at the dark intersection at 6:20 p.m.?
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Two layers decide it. First, the NO TURN ON RED plaque is time-banded 7 AM-9 AM and 4 PM-6 PM, and at 6:20 p.m. the ban has lapsed, so that sign no longer prohibits the turn. Note that the posted schedule controls, not a guess from traffic volume, and that some jurisdictions keep a general prohibition in place outside the band. Second, with the signal dark there is no red in the statutory sense at all; you are in a failed-signal situation with an officer directing traffic, and the officer's instruction outranks both the plaque and the default right-on-red rule. If the officer waves you through, go, after yielding to any pedestrians. If not, treat the dark head as a stop, yield to cross traffic, give way to pedestrians, and turn only from the proper lane after a full stop.