Instances of respiratory diseases are on the rise due to air pollution. We are in a world obsessed with modern urban infrastructure with freeways, tunnels and ring roads. We inevitably forget we have a price to pay for our advancement in technology and motor vehicle emissions.

Outdoor and indoor air pollution causes respiratory and other diseases. Factors that add to contamination of air are a various mixture of pollutants namely, Particulate Matter (PM), PM10, PM 2.5, ground level Ozone, Nitrogen Dioxide (NO2), Sulfur Dioxide (SO2) and CO.

It is estimated that 13 of the world's top 20 polluted cities are in India and only 3 are from China. Air pollution reduces the life expectancy by 3.2 years for 660 million Indians who reside in the cities. It is unfortunate that Delhi's air is found to be the most toxic in the world; because of high concentrations of PM 2.5. It reduces visibility and makes the air around us hazy.

To overcome this situation, two basic areas are to be understood that is congestion and rise in health complications. The damage caused by congestion and pollution is mostly because of 'rise in car ownership', 'high vehicle density', 'no fuel efficiency measures' and no 'prescribed standards to preserve fuel'. It can be controlled by understanding peak hours to regulate traffic effectively, advocating and popularising among masses the idea of frequently using public transport, improvising on car pooling policy, designing roads for public transport to meet the current requirements and understanding the pollution hotspots.

Economic and environmental impact of traffic congestion

India has 4.7 million km of road network across the country. The road network transports around 60% of goods and 85% of India's total passenger traffic. As road transport has significantly increased with improved connectivity between cities and villages, sales of automobiles and locomotion of freight by roads are growing rapidly. To keep up with the growing demand, the Government of India, in the 12th Five Year Plan (2012- 17), has reserved 20% of the investment of US $1 trillion to develop the country's roads.

Traffic congestion has become a serious issue in the urban landscape in India. It was found that congestion leads to annual economic burdens ranging from $83 billion to $124 billion. It is important to note that due to congestion, there arises a serious threat to public health. The excess air pollutant emissions during the period of congestion can worsen our health the most.

To solve the problem of congestion, the transport industry demands huge investment and sustainable practices in the existing routes and to expand its capacity further. Thus, India's public infrastructure in order to keep up with the growing demands has to improve and work on urban city planning. Recently, a $50 billion highway programme was unveiled to improve 40,000km of Indian highways. It is estimated that by 2021, 27.9 million more passengers will demand transport facilities.

The Delhi Master Plan 2021 is encouraging 80% of the commuters to use public transport by 2020 to overcome congestion. The plans undertaken by the government to overcome congestion include Delhi Metro System to provide access to NCR (Gurgaon, Noida and Ghaziabad), construction of ring roads to provide signal-free flow of traffic, introduction of 3,500 buses by Delhi Transport Corporation and widening of existing roads and flyovers.

It is estimated that daily trips to Delhi are expected to increase to 25.3 million by 2020. Although Delhi has extensive road networks, the biggest roadblock to fighting the problem of congestion and subsequent pollution is growing demand for automobiles. Most of the roads in India are saturated and choked by vehicles carrying more than their estimated capacity.

Health impacts of air pollution

As per a recent WHO report, only 12% of the urban population worldwide complies with the global health organisation's air quality guideline levels and half of the urban population is exposed to air pollution that is 2.5 times higher than the prescribed levels. The factors that contribute to the steep rise in air pollution are coal-fired power plants, private transport motor vehicles, use of biomass for cooking and heating.

To tackle this challenge to clean the air, urgent policy measures to ban the use of coals for "space heating" need to be implemented. Nation states must identify the health risks caused by air pollution, they must monitor the cities, encourage use of renewable or "clean fuels" for electricity production and focus on improving the motor vehicle engines.

Copenhagen and Bogota are two model cities that significantly improved the air quality by promoting 'active transport'. Huge attention was paid to urban public transport and introduction of reformatory measures namely walking and cycling. Thus, following a few concrete measures like encouraging energy-efficient houses, giving priority to safety of pedestrians in urban development, providing good public transport routes and managing waste efficiently can ensure clean air. Good air quality brings economic development and provides healthy lifestyles.

WHO's report (2014) said that 3.7 million people died (under 60 years) due to outdoor air pollution in the year 2012. Outdoor and indoor air pollution contains high concentrations of gaseous, solid particles and fine particulate pollution that causes heart diseases, stroke, respiratory illnesses and cancer.

With air quality deteriorating, India is ranked second for deaths caused by air pollution with a huge figure of 1.35 million annually. It is estimated that by 2050, 6.6 million premature deaths will occur globally per year due to increase in population and pollution. Indian doctors have time and again blamed the poor air quality for the significant rise in throat and chest diseases.

India is yet to create the safety net and secure sustainable policy measures. The impact on public health as a result of congestion is a burning issue and future evaluations and pragmatic policies are to be adopted to bring in positive results.

India fails on the pollution front not because development is massive but because the system fails in implementing policies. Planning is missing at many levels. Most traffic jams on the road are not because there are too many cars but because people haven't waited for their turn or the road is broken or there are barriers that don't need to be there. It will take India a while to start realising the failings the country has, until then the citizenry will have to suffer.

The AQI is an index for reporting daily air quality. The Ministry of Environment and Forests launched the National Air Quality Index last June and it indicates the levels of pollution in colour-coded categories and also informs citizens on how clean or unhealthy the air is. It also issues an advisory in the event of alarmingly high levels of pollution that may prove to be hazardous for people with respiratory disorders.