Advisory Speed on a Wet Downhill Curve
On a rainy Tuesday in October you are eastbound on a two-lane state route in Litchfield County, driving a pickup with a 1,200-pound load in the bed. The posted speed limit is 50 mph. You pass a yellow diamond curve sign with a 35 MPH advisory plaque, then a yellow diamond SLIPPERY WHEN WET sign, then a yellow diamond TRUCKS USE LOW GEAR sign. The road descends for about half a mile and the curve tightens after the first 200 feet. Your speedometer reads 48 mph. A sedan ahead brakes at the curve entrance, and your rear tires feel light as you cross a patched area. A passenger says, The sign says 35, so just go 35 and you will be fine.
1. What is the legal status of the 35 mph advisory speed, and how should the wet road and the load change your target speed?
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The 35 mph plaque is an advisory speed, not a regulatory limit. It appears in a yellow diamond assembly, and it reflects an engineering judgment about a comfortable speed for a passenger car under good conditions. The legal maximum remains the posted 50 mph, but the basic speed law still requires a speed that is reasonable for the conditions. Rain, a downhill grade, and a 1,200-pound load all push the safe speed below the advisory figure.
The passenger's logic is backwards. The advisory speed is an upper guideline for ideal conditions, not a target to meet in the rain. With a loaded pickup, the center of gravity is higher and the rear tires are more likely to lose grip, especially on a patched surface. A sensible target is well under 35 mph, perhaps 25 to 30 mph before the curve, with the low gear selected before the descent so engine braking helps control speed. Braking should be mostly finished before the curve, not carried into it. The exam is testing whether you treat yellow warning signs as information to combine with conditions, not as a guaranteed safe speed.
2. The sedan ahead brakes mid-curve. What should you do with brake, throttle, and steering, and why not brake hard?
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Ease off the throttle smoothly and let engine braking and the low gear slow you. If you need more speed reduction, apply light, steady brake pressure while the truck is still straight or only gently turning. Look through the curve toward the exit and make small, smooth steering inputs. Do not jerk the wheel to change lanes or to avoid the sedan.
Hard braking mid-curve is risky because it shifts weight forward, unloads the rear tires, and can trigger a skid in a vehicle that already feels light in the rear. On wet pavement the margin is smaller. If the rear begins to slide, stay off the brake, ease off the throttle, and steer smoothly in the direction you want the front of the truck to go. The SLIPPERY WHEN WET sign is a direct warning that friction is reduced, and the curve sign tells you the geometry is already demanding. The correct response is to reduce speed early, not to test the tires at the advisory number.
3. How do the SLIPPERY WHEN WET and TRUCKS USE LOW GEAR signs work together with the curve sign?
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The three signs describe different parts of the same hazard. The curve sign tells you that the road bends and gives you a shape and direction cue. The advisory plaque suggests a speed for that geometry. SLIPPERY WHEN WET tells you the surface friction is lower than the curve was designed for, so the advisory speed is not reliable in the rain. TRUCKS USE LOW GEAR tells you that a heavy vehicle should use engine braking on the descent to avoid overheating the brakes and to keep speed stable.
Together they mean: slow before the curve, select a lower gear before the grade, and treat the advisory speed as a fair-weather reference rather than a wet-weather target. The signs do not create a new legal limit, but they are evidence of the hazard. If a crash occurred, a driver who ignored all three would have a hard time arguing that 48 mph was reasonable. The exam favors the reasoning that warning signs stack: each one narrows the safe speed and the safe technique.