Vehicular emissions, particularly from diesel engines, are a significant source of air pollution in urban areas, contributing to high levels of particulate matter, nitrogen oxides, and other harmful pollutants.

Gasoline-powered vehicles primarily emit carbon monoxide (CO), a colorless, odorless gas that can cause headaches, dizziness, and impaired cognitive function at high concentrations.

Nitrogen oxides (NOx), emitted by vehicles and industrial processes, react with sunlight to form ground-level ozone, a harmful air pollutant that can cause respiratory problems and damage vegetation.

Emission control refers to the technologies and strategies used to reduce the release of pollutants from vehicles, such as catalytic converters, particulate filters, and engine modifications.

Natural gas is an alternative fuel that can be used in vehicles, offering lower emissions compared to traditional fossil fuels.

Electric vehicles do not produce tailpipe emissions, meaning they do not release pollutants such as carbon monoxide, nitrogen oxides, or particulate matter into the air.

Encouraging public transportation can reduce traffic congestion and improve air quality by reducing the number of vehicles on the road.

Retrofitting refers to the process of converting a vehicle to run on an alternative fuel, such as natural gas or propane, by modifying the engine and fuel system.

Brake wear is a significant source of particulate matter emissions from vehicles, particularly in urban areas with frequent stop-and-go traffic.

Vehicle restriction schemes are policies that limit the number of vehicles allowed on the road, often during peak traffic hours or in specific areas.

Creating car-free zones near schools and hospitals can reduce traffic-related air pollution and improve air quality for students, patients, and staff.

Intelligent Transportation Systems (ITS) use technology to collect and analyze traffic data, and to manage traffic flow in real time, aiming to reduce congestion and improve air quality.

Aircraft engines emit significant amounts of nitrogen oxides (NOx), particularly during takeoff and landing, contributing to air pollution near airports.

Emission control areas (ECAs) are designated areas where ships are required to use cleaner fuels or install emission control technologies to reduce air pollution.

Using dust control measures, such as water sprays and wind screens, can help reduce air pollution from construction activities by preventing the release of particulate matter into the air.