Methane is not a major air pollutant emitted by vehicles. The main air pollutants emitted by vehicles are carbon monoxide, nitrogen oxides, and sulfur dioxide.

Hydrofluorocarbons are not emitted by vehicles. The main greenhouse gases emitted by vehicles are carbon dioxide, methane, and nitrous oxide.

Cars are not a major source of noise pollution from transportation. The main sources of noise pollution from transportation are aircraft, trains, and trucks.

Increased mobility is not a negative environmental impact of transportation. Increased mobility can actually have positive environmental impacts, such as reduced traffic congestion and improved air quality.

All of the above strategies can help to reduce air pollution from transportation. Using more fuel-efficient vehicles, promoting public transportation, and encouraging walking and biking can all help to reduce the number of vehicles on the road, which can lead to reduced air pollution.

All of the above strategies can help to reduce greenhouse gas emissions from transportation. Using more renewable energy sources, improving energy efficiency, and reducing the number of vehicles on the road can all help to reduce the amount of greenhouse gases emitted by transportation.

All of the above strategies can help to reduce noise pollution from transportation. Using quieter vehicles, building noise barriers, and planting trees and shrubs can all help to reduce the amount of noise pollution generated by transportation.

All of the above can be positive environmental impacts of transportation. Reduced traffic congestion can lead to improved air quality and increased mobility can lead to reduced greenhouse gas emissions.

All of the above can be challenges to reducing the environmental impacts of transportation. The high cost of new technologies, the need for infrastructure improvements, and the resistance to change from consumers can all make it difficult to reduce the environmental impacts of transportation.

All of the above are important things that can be done to reduce the environmental impacts of transportation. Investing in new technologies, improving infrastructure, and changing consumer behavior can all help to reduce the environmental impacts of transportation.

All of the above are likely to play a role in the future of transportation. Electric vehicles, autonomous vehicles, and shared mobility can all help to reduce the environmental impacts of transportation and make transportation more efficient and accessible.

All of the above strategies can help to make transportation more sustainable. Using more renewable energy sources, improving energy efficiency, and reducing the number of vehicles on the road can all help to reduce the environmental impacts of transportation.

All of the above can be challenges to making transportation more sustainable. The high cost of new technologies, the need for infrastructure improvements, and the resistance to change from consumers can all make it difficult to make transportation more sustainable.

All of the above are important things that can be done to make transportation more sustainable. Investing in new technologies, improving infrastructure, and changing consumer behavior can all help to make transportation more sustainable.

All of the above are likely to play a role in the future of sustainable transportation. Electric vehicles, autonomous vehicles, and shared mobility can all help to reduce the environmental impacts of transportation and make transportation more efficient and accessible.