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Minimum speedUnited 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

5. Minimum speed

A minimum speed is the lowest speed that vehicles are required to maintain on a particular road or under specified conditions. Minimum-speed rules are intended to prevent vehicles traveling unnecessarily slowly from disrupting traffic or creating large speed differences between road users.

A minimum speed does not require drivers to maintain that speed when traffic, weather, visibility, road conditions or safety require them to slow down. The way minimum speeds are indicated and enforced varies between countries.

Minimum speed
Speed limit of 55 mph and a minimum speed of 45 mph. (Huntsville, United States)
Wikimedia.org • formulanone • CC BY-SA
Does the United States have one nationwide motorway minimum speed?

No single numerical motorway minimum applies nationwide. State rules and applicable posted restrictions govern, normally in mph. A minimum on one state’s road must not be transferred automatically to another state or section.

🔗 law.lis.virginia.gov • Code of Virginia section46.2-877 — impeding traffic and signed minima, safety/law exceptions

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

Can US slow-driving rules apply without a numerical minimum sign?

Yes. For example, Virginia prohibits driving so slowly that it impedes normal, reasonable traffic flow, except where slowing is needed for safe operation or to comply with the law. The state’s rule is not a nationwide numerical minimum.

🔗 law.lis.virginia.gov • Code of Virginia section46.2-877 — impeding traffic and signed minima, safety/law exceptions

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

Start of a minimum speed. Start of a minimum speed.

English • R2-4a • Minimum speed. Sets a minimum speed of 40 mph, as shown in the illustration, subject to safety requirements and applicable law.

Sources

🔗 Commons.wikimedia.org
🔗 Mutcd.fhwa.dot.gov • FHWA: MUTCD, 11th Edition with Revision1, PDF page127

Image via Commons.wikimedia.org
Federal Highway Administration - MUTCD • Public domain • Source revision 2013-01-13. Wikimedia original unmodified.

Does a US minimum-speed rule require unsafe travel in a queue?

No. Virginia’s rule expressly recognises safe-operation and legal exceptions. Follow the actual state’s requirements, slow or stop with the traffic and keep a safe gap. Do not use a minimum to justify driving into a hazard.

🔗 law.lis.virginia.gov • Code of Virginia section46.2-877 — impeding traffic and signed minima, safety/law exceptions

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

1 United States 2 Freeway 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 Yield 20 Roundabout 21 Road narrowing 22 Crosswalk 23 Railroad 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 Road work 35 Height limit 36 Weight limit 37 Radar speed sign 38 Selective barriers 39 Traffic signals 40 Traffic signals ahead 41 Pedestrian signals 42 Pavement markings 43 Bike box 44 Speed feedback 45 Driver's license 46 Traffic mirror 47 Emergency telephone 48 Bicycle 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 Backing up 58 U-turn 59 Carpool 60 Detour 61 Uncontrolled intersection 62 Ramp 63 Exit 64 Horseback riding 65 Emergency exit 66 Runaway truck ramp 67 Oversize load 68 City limit 69 Tourist attraction 70 Horn 71 Axle weight limit 72 License plate 73 Charging station 74 Flooding 75 Dip 76 Horse 77 Local traffic 78 Pedestrian 79 Bicyclist 80 Motorcycle 81 Truck 82 Bus 83 Police 84 Ambulance 85 Police signals 86 Gravel road 87 Pothole 88 Median 89 Public property 90 Path 91 Particulates 92 Air pollution 93 Interchange 94 Rush hour 95 Gas station 96 Road code 97 Two-way traffic 98 Passing lane 99 Street gutter 100 Road debris ...