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Speed feedbackUnited 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

44. Speed feedback

Speed feedback is a traffic-safety system that measures an approaching vehicle's speed and displays it back to the driver. The display may show the measured speed together with a message, colour or symbol indicating whether the vehicle is travelling within the applicable speed limit.

Speed feedback displays are intended primarily to make drivers aware of their speed and encourage them to slow down when necessary. They normally serve a preventive or educational purpose rather than establishing a new speed limit.

Speed feedback
25 mph speed-limit and speed-feedback signs on Maryland Route 281 at Big Elk Creek. (Elkton, Maryland, United States)
Wikimedia.org • Famartin • CC BY-SA
What does a speed-feedback display show drivers in the United States?

US radar speed-feedback signs may display a driver’s measured speed, usually in mph, often beside an official SPEED LIMIT sign. FHWA MUTCD guidance distinguishes such feedback from the regulatory speed-limit indication.

🔗 mutcd.fhwa.dot.gov • FHWA MUTCD11th Edition including Revision1 December2025 — relevant warning/regulatory/guide signs, lines and restroom symbols

Does the number on a speed-feedback board set the legal speed limit in the United States?

Normally no. A reading showing your measured speed is not itself a new regulatory limit. The limit comes from applicable laws and legally prescribed fixed or variable speed-limit signs; a separate enforceable speed sign must still be obeyed.

🔗 mutcd.fhwa.dot.gov • FHWA MUTCD11th Edition including Revision1 December2025 — relevant warning/regulatory/guide signs, lines and restroom symbols

Is every speed-feedback board an enforcement camera in the United States?

No. The FHWA describes radar speed-feedback signs as displays informing approaching drivers of their speed. Their existence does not by itself establish whether a separate camera or police speed-enforcement system operates nearby.

🔗 mutcd.fhwa.dot.gov • FHWA MUTCD11th Edition including Revision1 December2025 — relevant warning/regulatory/guide signs, lines and restroom symbols

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 ...