Hill Warning Signs

The percentage is the grade - the vertical drop per 100 feet of road. A 6% grade means the road falls 6 feet for every 100 feet you drive; 8% falls 8 feet. The higher the number, the steeper the hill and the more gravity works on your vehicle. You can post the exact figure with a Custom % Grade sign (W7-3).

Grade is rise over run: divide the vertical change by the horizontal distance and multiply by 100. If a road drops 30 feet over 500 feet, that's 30 / 500 = 0.06, or a 6% grade. The sign does this math for you and posts the result, so you can gauge the hill at a glance instead of eyeballing it.

Shift into a low gear at the top of the hill, before you pick up speed - the same gear you'd use to climb it is a good rule of thumb for descending it. Low gear lets the engine hold your speed so you're not leaning on the brakes the whole way. That's exactly what a Use Low Gear sign (W7-2) is telling truckers to do.

Slow down before you crest the hill, drop into a low gear so the engine does the braking, and use short, firm brake applications rather than riding the pedal, so the brakes can cool. Keep an eye out for a runaway truck ramp on long grades. The goal is to reach the bottom with your brakes still cool - not to test how long they'll last.

If the brake pedal goes soft or you smell them getting hot, downshift to a lower gear immediately to let the engine slow you and take load off the brakes. Don't pump fading brakes hoping they recover. If there's a runaway truck ramp ahead, use it - that's what it's for. An escape ramp costs you a tow; failed brakes at the bottom of a hill cost far more.

A Runaway Truck Ramp sign (the W7-4 series) marks an emergency escape ramp - usually a long bed of loose gravel climbing away from the road - where a truck that has lost its brakes can safely stop. The sign tells drivers the ramp is coming so they can aim for it in an emergency instead of riding a runaway to the bottom. They're posted on long, steep mountain grades.

The safety concern is almost always the descent, so the standard Hill sign (W7-1) shows a truck pointing downhill and warns the downgrade side. A climb mainly costs you power, not control, so it gets less signing - though the same grade percentage applies going up. When a hill both rises and falls sharply, the descent side is the one that gets the hill warning and any "Use Low Gear" plaque.

The idea is universal - most countries post a steep-hill warning - but the design differs. The U.S. MUTCD W7-1 is a yellow diamond with a truck on a slope; many other countries use a red-bordered triangle showing a percentage on a ramp symbol. Ours follow the U.S. federal MUTCD, which most state manuals adopt, so they match what American drivers already recognize.

Yes. The Custom Downgrade sign (W7-1b) lets you build in your grade and mileage, and the Custom % Grade sign posts the exact steepness. For a custom message or a bulk order for a mountain route, call our sales team at 888-343-3771 (Mon-Fri, 8am-7pm EST) or email customerservice@smartsign.com.