Air pollutionSlovenia

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


55. 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 Slovenia 2 Motorway 3 Zone 4 Speed limit 5 Bike path 6 Tunnel 7 Pedestrian zone 8 Speed bump 9 Customs 10 One-way traffic 11 Slope 12 Bus lane 13 Dead end 14 Stop sign 15 Roundabout 16 Priority road 17 Road narrowing 18 Pedestrian crossing 19 Railway crossing 20 Mandatory direction 21 School area 22 Crossing animals 23 Rockfall 24 Chevron 25 Wrong-way driving 26 Roadworks 27 Height limit 28 Weight limit 29 Traffic lights 30 Pedestrian lights 31 Traffic mirror 32 International border 33 Cycling route 34 Parking 35 No stopping 36 Parking disc 37 Reversing 38 Emergency exit 39 City limit 40 Licence plate 41 Charging station 42 Dangers 43 Dip 44 Pedestrian 45 Cyclist 46 Truck 47 Bus 48 Police 49 Ambulance 50 Taxi 51 European emission standard 52 Pothole 53 Path 54 Particulates 55 Air pollution 56 Rush hour 57 Road code 58 Street gutter 59 Cargo bike 60 Forestry vehicle 61 Construction vehicle 62 Semi-trailer truck 63 Trolleybus 64 Speed pedelec 65 Delivery vehicle 66 Idling 67 Tow truck 68 Four-wheel drive 69 No vehicles 70 Bicycle 71 Motorcycle equipment 72 Rail track 73 Caravan 74 Trailer 75 Tow hitch 76 Fire truck 77 Siren 78 Convoy 79 Emergency vehicle lighting 80 Agricultural machinery 81 Electric bicycle 82 Electric vehicle 83 Pedelec 84 Quadricycle 85 Microcar 86 All-terrain vehicle 87 Van 88 Recreational vehicle 89 Scooter 90 Trikke 91 Personal mobility device 92 Skateboard 93 Segway 94 Kick scooter 95 Roller skates 96 Mailman 97 Hitchhiker 98 Toddler 99 Child 100 Disability ...