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Slippery roadUnited 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

28. Slippery road

A slippery road has reduced tyre grip and can make steering, braking and acceleration less effective. Roads may become slippery because of rain, ice, snow, mud, oil, loose material or other substances on the surface. Drivers should reduce speed, increase their following distance and avoid sudden steering, braking or acceleration. Extra caution is needed in bends, on bridges and wherever the road surface changes unexpectedly.

Slippery road
Slippery-road warning sign on eastbound Interstate 80 near Delaware Water Gap. (New Jersey, United States)
Wikimedia.org • Famartin • CC BY-SA
What can make roads slippery in the United States?

Be prepared for rain, snow or freezing rain in colder states and loose gravel elsewhere. A surface can become slippery even if it looks clear, and different parts of the road may have very different grip.

🔗 dmv.ca.gov • California DMV — safe driving, space and hazard precautions; examples are illustrative

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

How should you drive on a slippery road in the United States?

Reduce speed early, increase the gap to the vehicle ahead and use smooth steering, braking and acceleration. Do not rely on the posted maximum as a safe target when grip is poor.

🔗 dmv.ca.gov • California DMV — safe driving, space and hazard precautions; examples are illustrative

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

Does a slippery-road warning sign in the United States automatically impose a lower number?

The warning sign highlights a reduced-grip risk; it normally does not itself prescribe a new numerical speed limit. A separate speed-limit sign, temporary restriction or local condition may still apply. Travel below the legal maximum when necessary for safety.

🔗 dmv.ca.gov • California DMV — safe driving, space and hazard precautions; examples are illustrative

🔗 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 ...