Support us

SlopeUnited States

An introduction to the traffic rules and road signs of United States. Learn about driving, road safety and much more in our illustrated book, with answers to frequently asked questions.

For informational purposes only. Always follow official regulations. Some content and images were created with AI assistance.

Traffic signs
Traffic rules
United States

14. Slope

A slope is a section of road that rises or descends noticeably. A steep slope can affect vehicle speed, braking distance, traction, visibility and the ability of heavy or low-powered vehicles to maintain a steady speed.

Warning signs may indicate a steep ascent or dangerous descent and may show the gradient as a percentage. Drivers should adjust their speed early, select a suitable gear and remain prepared for slow vehicles, bends and changing road conditions.

Steep-grade warning sign on eastbound Interstate 280 near Exit 8B. (West Orange, New Jersey, United States)
Wikimedia.org • Famartin • CC BY-SA
What does a steep-slope warning mean in the United States?

US driving rules vary by state. The California handbook discusses mountain roads and speed suitable for the conditions; a hill warning is separate from a posted limit.

🔗 dmv.ca.gov • California DMV — signs, junction priority, crosswalks and steep narrow roads

🔗 mutcd.fhwa.dot.gov • FHWA MUTCD11th Edition including Revision1 — relevant signs/markings; device standard, not state law

How should I approach a steep descent in the United States?

Reduce speed before the descent and select a suitable gear to help control the vehicle. Keep enough following distance and avoid building up speed that requires continuous heavy braking. A warning gives no fixed safe descent speed: the gradient, surface, visibility, load and vehicle can require a speed well below the legal maximum.

🔗 dmv.ca.gov • California DMV — signs, junction priority, crosswalks and steep narrow roads

🔗 mutcd.fhwa.dot.gov • FHWA MUTCD11th Edition including Revision1 — relevant signs/markings; device standard, not state law

What should I check when meeting or overtaking on a slope in the United States?

In California, when two vehicles meet on a steep road where neither can pass, the downhill vehicle must yield by backing up until the uphill vehicle can pass. This state rule should not be presented as a single rule for every US jurisdiction.

🔗 dmv.ca.gov • California DMV — signs, junction priority, crosswalks and steep narrow roads

🔗 mutcd.fhwa.dot.gov • FHWA MUTCD11th Edition including Revision1 — relevant signs/markings; device standard, not state law

1 United States 2 Motorway 3 Expressway 4 Speed limit 5 Minimum speed 6 Advisory speed 7 Bike path 8 Pedestrian warning 9 Tunnel 10 Bridge 11 Speed bump 12 Toll road 13 One-way traffic 14 Slope 15 Bus lane 16 Bus stop 17 Dead end 18 Stop sign 19 Give way 20 Roundabout 21 Road narrowing 22 Pedestrian crossing 23 Railway crossing 24 Mandatory direction 25 Turn prohibition 26 School area 27 Crossing animals 28 Slippery road 29 Rockfall 30 Aircraft 31 Curve 32 Chevron 33 Wrong-way driving 34 Roadworks 35 Height limit 36 Weight limit 37 Radar speed sign 38 Selective barriers 39 Traffic lights 40 Traffic lights warning 41 Pedestrian lights 42 Road markings 43 Bike box 44 Speed feedback 45 Driving licence 46 Traffic mirror 47 Emergency telephone 48 Cycling route 49 Parking 50 No parking 51 No stopping 52 Parallel parking 53 Park and ride 54 Kiss and ride 55 Disabled parking 56 Traffic management 57 Reversing 58 U-turn 59 Carpool 60 Detour 61 Uncontrolled crossroad 62 Ramp 63 Exit 64 Horse riding 65 Emergency exit 66 Runaway truck ramp 67 Oversize load 68 City limit 69 Tourist attraction 70 Horn 71 Axle weight limit 72 Licence plate 73 Charging station 74 Flooding 75 Dip 76 Horse 77 Local traffic 78 Pedestrian 79 Cyclist 80 Motorcycle 81 Truck 82 Bus 83 Police 84 Ambulance 85 Police signals 86 Gravel road 87 Pothole 88 Median strip 89 Public property 90 Path 91 Particulates 92 Air pollution 93 Interchange 94 Rush hour 95 Filling station 96 Road code 97 Two-way traffic 98 Passing lane 99 Street gutter 100 Road debris ...