PoliceUnited States

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


83. Police

Police are public authorities responsible for enforcing laws, maintaining public safety and managing situations that may affect road traffic. In traffic, police officers may control vehicles, enforce traffic rules, investigate collisions, direct traffic and respond to emergencies.

Road users must follow lawful instructions given by police officers or other authorised traffic-control personnel. Police directions may temporarily override traffic lights, road signs or normal traffic arrangements, depending on local law.

Metro Transit Police Chevrolet Tahoe. (Maryland, United States)
Wikimedia.org • Davest3r08 • CC BY-SA
What is the role of police in road traffic?

Police help enforce traffic laws, manage traffic, investigate collisions and respond to dangerous situations. They may also carry out roadside checks and direct road users.

Must you obey a police officer directing traffic?

Yes. Lawful directions given by an authorised police officer must be followed. In many countries, those directions take precedence over traffic lights, road signs and normal priority rules.

What should you do if police signal you to stop?

Slow down, follow the officer's directions and stop at a safe location as instructed. Do not make sudden movements or continue driving unless directed to do so.

Can police direct you through a red traffic light?

Yes, where authorised by local law. A police officer controlling traffic may instruct road users to proceed even when a traffic light or sign would normally require them to stop.

Can police check your driving documents?

Yes. Police may require drivers to provide documents such as a driving licence, vehicle registration, identification or proof of insurance according to local law.

Can police carry out alcohol or drug checks?

Yes. Traffic police may conduct legally authorised alcohol and drug checks using procedures such as breath, saliva or other approved tests.

Can police temporarily close a road?

Yes. Roads or lanes may be temporarily closed or traffic diverted because of collisions, emergencies, investigations, public events or other safety concerns.

What should you do near police controlling an accident scene?

Reduce speed, remain alert and follow all directions. Do not enter a closed area or interfere with emergency personnel, and leave sufficient space for emergency vehicles.

What should you do when a police vehicle approaches with emergency signals?

Follow the local rules for priority vehicles. Drivers generally have to make sufficient space, give way and stop where necessary so that the emergency vehicle can pass safely.

Can police order a parked vehicle to be moved?

Yes, where local law permits it. Police or another authorised authority may require a vehicle to be moved when it obstructs traffic, creates danger or must be removed for operational reasons.

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 ...