Support us

Minimum speedUnited States

Learn traffic rules with clear explanations and visual examples in our illustrated book, designed to make studying simple and engaging.

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 travelling 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
What is a minimum speed?

A minimum speed is the lowest speed that vehicles are normally required to maintain on a particular road or in a specified traffic situation.

Must you maintain the minimum speed in dangerous conditions?

No. Safety takes priority. Drivers may need to travel more slowly because of congestion, poor weather, limited visibility, roadworks or another legitimate reason.

Why are minimum speeds used?

Minimum speeds can help reduce excessive differences in speed between vehicles and prevent unnecessarily slow traffic from obstructing normal traffic flow.

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 ...