School Zone, Truck Plaque, and Work Zone Speed Limits on a Two-Lane Highway
You are driving north on a two-lane US highway in Oklahoma at 7:40 a.m. on a Tuesday in September. Traffic is light and the pavement is dry. The last posted speed limit was 65 mph. Ahead, a white rectangular sign reads SPEED LIMIT 55 with a smaller black-on-white plaque reading TRUCKS 50. Two hundred feet later, a yellow diamond shows a school bus symbol, followed by a fluorescent yellow-green pentagon school sign and a rectangular SCHOOL SPEED LIMIT 25 sign with a WHEN FLASHING plaque; the beacon is not flashing. A block after that, orange signs read ROAD WORK AHEAD and SPEED LIMIT 35, and a flagger is holding a SLOW paddle. No workers are visible in the work area, but a grader is parked partly on the shoulder. Your passenger asks whether the school-zone limit applies and whether the 35-mph sign is enforceable when no one is working.
1. At the moment you reach the school zone, the beacon is off. Which speed limit applies to your passenger car, and what would change if the beacon were flashing?
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The white SPEED LIMIT 55 sign is the operative regulatory limit for your passenger car. The TRUCKS 50 plaque is a separate restriction for trucks, so it does not lower your limit. The school-zone assembly is conditional: the 25 mph sign carries a WHEN FLASHING plaque, and the beacon is off, so the 25 mph limit is not in effect at that moment. You still should slow and scan for children because the pentagon school sign warns of a school area and children can arrive early or late. If the beacon were flashing, the 25 mph limit would replace 55 mph for the school zone. The key reasoning is to read the sign assembly as a package: white rectangular signs are regulatory, the plaque states the condition, and the yellow-green school signs identify the area rather than independently setting a limit.
2. The flagger holds a SLOW paddle and no workers are visible. What does SLOW require, and is the orange 35 mph sign enforceable?
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The SLOW paddle directs you to proceed through the work area at a reduced, cautious speed, prepared to stop if conditions change; it does not require a full stop the way STOP does. The orange SPEED LIMIT 35 sign is still a regulatory speed limit for the temporary traffic control zone. Its enforceability does not depend on workers being visible at that instant, because the sign establishes the limit and the work zone remains active. The parked grader and narrowed lane are hazards even with no one in them. If the flagger rotates the paddle to STOP, you must stop before the flagger or the designated stop point and wait for a release. Do not treat the absence of workers as permission to resume 55 mph before a sign or flagger ends the restriction.