Five-Way Intersection: Green Arrow, Two-Stage Rule and a One-Way Trap
21:45 on a dry weekday. A rider on a 1,000 cc 大型二輪 is in the right-turn lane of a four-lane 市道 approaching a large five-way intersection. Below the vehicle signal hangs a small 原付二段階右折 sign, and a supplementary plate under the signal reads 「7-9 17-19 右折禁止」. The signal shows 青 plus a lit green 右折矢印. To the left of his lane lies a white 導流帯. The road he wants is about 20 m past the intersection centre on the right: a narrow street carrying a blue rectangular sign with a white arrow pointing toward him. An oncoming van waits at the stop line. A pedestrian stands on the corner. His plan is to follow what he believes is the 原付 rule - wait at the two-stage stop point, then cross with the far-side signal. As a fallback he considers making a U-turn at the intersection and approaching the street from the other end; a 転回禁止 sign stands on the left corner.
1. Must he perform a 二段階右折 here? Explain what the sign applies to and how he should position and turn.
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No. 二段階右折 is a rule for 原動機付自転車 and 小型特殊自動車 at intersections designated by that sign. It exists because those vehicles are limited to 30 km/h and are treated differently in traffic. A 大型自動二輪車 is a 自動二輪車, not a 原付, so it turns right in a single movement, like any other motor vehicle.
That means: enter the right-turn lane, position near the centre line of the road (not at the left edge like an 原付), indicate right, and wait for a safe gap or the 右折矢印. With the green 右折矢印 lit, oncoming through traffic is being held, so he has priority over the waiting van - but priority is not immunity. The arrow ends without warning, and the oncoming van's driver may anticipate the change; he should still confirm that the van has not crept forward and that the pedestrian is not stepping out.
Following the 原付 method here would be actively dangerous: he would sit at the left edge of the intersection from which no driver expects a 1,000 cc machine to begin a right turn.
2. Can he enter the street on the right? Interpret the blue sign and the supplementary plate, and state what he should actually do.
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The blue rectangular sign with a white arrow is a 一方通行 sign; the arrow shows the direction in which traffic is permitted to travel. Here the arrow points toward him, which means traffic in that street flows out of it toward the intersection. Entering it would be 逆走 - driving against the designated direction - and is prohibited regardless of how short the distance or how quiet the street looks at 21:45.
The supplementary plate 「7-9 17-19 右折禁止」 prohibits right turns only during 07:00–09:00 and 17:00–19:00, so the right turn itself is not time-prohibited now. The 導流帯 to his left is a painted guidance zone, not a lane; he must not use it to widen his turn. What he should do: do not turn into that street. Continue straight through the intersection, or take the legal right turn into a different street, then work back to his destination via a permitted entry. Reading the sign before committing to the manoeuvre is the whole point - a 逆走 error at night, into a narrow street, is precisely the situation that produces a head-on collision.
3. Assess the U-turn fallback and explain whether the green arrow removes his duty to check.
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The fallback fails on two counts.
First, the 転回禁止 sign prohibits 転回 at this intersection. That prohibition is about the manoeuvre, not about intent: circling back to approach the street from the other end by turning around here is exactly what the sign forbids, and the wide five-way geometry does not create an exception.
Second, even without the sign, a U-turn across four lanes at a signalised intersection, at night, with an oncoming van already waiting and a pedestrian on the corner, exposes him broadside to traffic that has a green light for a different movement. The lawful and safer alternative is to continue in his direction of travel and take the next legal left or right that lets him rejoin the street from its permitted end.
On the arrow: a green 右折矢印 gives him priority over conflicting oncoming through traffic, but it does not transfer responsibility. Pedestrians, cyclists, emergency vehicles and drivers who misjudge the phase still exist, and the arrow can terminate while he is mid-turn. The correct habit is to treat the arrow as permission to proceed after verification, not as a guarantee that the path is clear.