Air pollutionCzechia

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


81. Air pollution

Air pollution is the presence of gases, particles or other substances in the air at concentrations that can harm human health, the environment or ecosystems. Road traffic contributes to air pollution through exhaust emissions and through non-exhaust sources such as brake wear, tyre wear and road dust.

Important traffic-related pollutants include nitrogen oxides, particulate matter, carbon monoxide and volatile organic compounds. Some pollutants are emitted directly by vehicles, while others can form in the atmosphere through chemical reactions. Vehicle-emission standards, cleaner technologies and traffic-management measures are used to reduce these emissions.

Air pollution
Black smoke emitted from a vehicle exhaust on a road in Kamonyi District. (Rwanda)
Wikimedia.org • Emmanuelkwizera • CC BY-SA
What is air pollution?

Air pollution is contamination of the air by gases, particles or other substances that can adversely affect human health, the environment or ecosystems.

How does road traffic cause air pollution?

Vehicles produce pollutants through fuel combustion, exhaust systems, brake wear, tyre wear and road-surface interaction. Moving traffic can also resuspend dust already present on the road.

Which air pollutants are associated with road traffic?

Important traffic-related pollutants include nitrogen oxides, particulate matter, carbon monoxide and volatile organic compounds. Their relative importance depends on the vehicle, fuel and driving conditions.

What is nitrogen dioxide?

Nitrogen dioxide (NO2) is an air pollutant associated particularly with combustion processes and road traffic. High concentrations are commonly found near busy roads and densely trafficked urban areas.

What is particulate matter?

Particulate matter consists of tiny solid particles or liquid droplets suspended in the air. Road traffic can produce particles from exhaust, brakes, tyres and road surfaces.

Is CO2 the same as ordinary air pollution?

No. Carbon dioxide is primarily regulated as a greenhouse gas because of its contribution to climate change. Local air-quality pollution generally focuses on substances such as nitrogen dioxide, particulate matter, ozone and other pollutants that directly affect air quality and health.

Do electric vehicles cause air pollution?

Fully electric vehicles produce no combustion-engine exhaust emissions while driving, but they can still contribute to non-exhaust particulate emissions through tyres, brakes and road wear.

Can air pollution be worse near busy roads?

Yes. Concentrations of traffic-related pollutants can be higher close to heavily trafficked roads because many emissions occur close to ground level and near where people live and travel.

What is a low-emission zone?

A low-emission zone is an area where access by more polluting vehicles is restricted in order to reduce traffic-related air pollution. Access criteria may depend on factors such as fuel type, vehicle category and emission standard.

How can traffic-related air pollution be reduced?

Measures include cleaner vehicles, stricter emission standards, effective emission-control equipment, low-emission zones, public transport, cycling and walking, as well as traffic-management measures that reduce unnecessary congestion and emissions.

1 Czechia 2 Motorway 3 Residential area 4 Zone 5 Speed limit 6 Advisory speed 7 Footpath 8 Bike path 9 Shared-use path 10 Pedestrian warning 11 Pedestrian zone 12 Speed bump 13 Customs 14 Slope 15 Bus lane 16 Bus stop 17 Dead end 18 Stop sign 19 Give way 20 Roundabout 21 Priority road 22 Road narrowing 23 Priority over oncoming traffic 24 Give way to oncoming traffic 25 Pedestrian crossing 26 Railway crossing 27 School area 28 Crossing animals 29 Slippery road 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 Priority at the next junction 40 Traffic lights 41 Traffic lights warning 42 Pedestrian lights 43 Road markings 44 Junction layout 45 Bike box 46 Speed feedback 47 Location marker 48 Countdown markers 49 Traffic mirror 50 Emergency telephone 51 International border 52 Pedestrian underpass 53 Cycling route 54 Parking 55 No parking 56 No stopping 57 Park and ride 58 Kiss and ride 59 Disabled parking 60 Traffic management 61 Reversing 62 Road surface 63 Provisional licence 64 Hazardous cargo 65 Runaway truck ramp 66 Tourist attraction 67 Axle weight limit 68 Licence plate 69 Charging station 70 Dangers 71 Cyclist 72 Bus 73 Police 74 Ambulance 75 Taxi 76 Police signals 77 European emission standard 78 Pothole 79 Path 80 Particulates 81 Air pollution 82 Rush hour 83 Road code 84 Train station 85 Street gutter 86 Cargo bike 87 Forestry vehicle 88 Construction vehicle 89 Semi-trailer truck 90 Trolleybus 91 Speed pedelec 92 Delivery vehicle 93 Idling 94 Tow truck 95 Four-wheel drive 96 No vehicles 97 Bicycle 98 Motorcycle equipment 99 Tram 100 Rail track ...