In the twentieth-century, as mankind has improved their living quality, they are very much the reason for their own casualty. Bangladesh is a small country, but the population is large nevertheless. For a convenient movement of this large population, there are millions of cars on the road. However, the roads of this country are too narrow for the large number of private cars, so, naturally, they cause traffic jam. Our dearest city, Dhaka, was ranked as 4th least liveable city in 2021 by the UK's Economist Intelligence Unit. Main two reasons for the unlivable city are "pollution" and "traffic jam". Pollution and traffic are interconnected. Long traffic congestion on road plays a major role in increasing air pollution and noise pollution. Even though Dhaka is considered to be a megacity, but no other megacities in the world is as occupied with traffic jam as Dhaka. In this crowded city, we can no longer wake up with the sound of singing bird; instead, nowadays we have to wake up with the sound of noisy car engines and horns. There was a time when Dhaka was known as the city of Mosque, but in present days scholars call it a city of private cars and traffic. According to "World traffic Index-2019" which is published by a research institute "Nam Bio", Dhaka took 1st position in traffic congestion. Not only that, Dhaka is also at the top of the time wastage and traffic inefficiency index. Though only three years ago Dhaka was 3rd position on this report. Consequently, the increasing number of vehicles, especially private car should be responsible for the rise of traffic in Dhaka City.

Currently, people are using cars so much that traffic is one of the major problems in many countries of the world. To solve this problem worldwide, every year on September 22, the "World Car-Free Day" is celebrated with various initiatives in many countries. The first "World Car-Free Day" was celebrated in 2000 and in 2006 in our country the day was celebrated by some people and individual organization, by their own arrangement. But in 2016 onwards our government started to celebrate this day for the first time. The purpose of this day is to unveil one day a month by making the roads free from excessive vehicles, making renovations and vacations, providing free spaces for sports or diversion, giving people some relief from the mechanical life for at least one day. September 22, 2021 (Tuesday) World Car Free Day will be celebrated across the country. The theme of the day this year is 'Walking and cycling, building a livable city'. The day will be celebrated with the joint initiative of 70 government and no- government organizations of the country including Stamford University Bangladesh. A press conference has been organized by the Dhaka Transport Coordinating Authority (DTCA) for this day. An event called Private Car Free Day is organized on the first Saturday of every month in front of Manik Mia Avenue in an effort of various organizations. The event has been closed for the past year due to COVID situation.

In the context of our country where public transport could have been the ideal transportation system for us, we prioritized private cars for our daily movement. People are being encouraged to use private cars day by day due to various limitations and restrictions on mass transportation. First of all, the inadequacy of mass transportation; the situation is that there is disparity in the number of public transports in some overcrowded routes compared to the others. For example, from Farmgate to Mirpur, this route has more public transports in number than other routes. At the same time not having a strict ticket system, collection of the extra ticket cost, not having a secure environment for women, congested situations, and lack of comfort - is also the reason for making public transportation system undesirable. Moreover, private car symbolizes luxury, comfort and ostentation which encourage people to choose car over public transports.

According to a research report published by the US-based organization Democracy International (DI) in 2017 on September 22, 6 percent of people in Dhaka City who use private cars occupy 76 percent of the road. Between 6 and 8 percent of the road is occupied by public transport, and the rest of the road is taken by illegal parking. Thus, private car takes more space in the street than public transports. If we compare private car with public transport, it is clear that private car takes more road space in less efficiency.

A survey by Stamford University Bangladesh's Department of Environmental Science found that 3 private cars, occupied by 12 people, take the same space as a bus that could accommodate 36 to 40 people. On the other hand, one private car occupies the same amount of space as a human hauler (Tempo or Laguna). But a human hauler can accommodate 14 people while a car can only take 4. In some cases, the difference is that some wealthy family has at least two or more cars; therefore, for 2 to 4 people at least two private cars ply on the street, which can be easily replaced by 12 bicycles. As the use of private cars is increasing, the demand for fuels is rising, increasing the rate of air pollution as well. A roundtable discussion titled "Traffic in Dhaka Metropolitan City: Financial and Health Problems" organized by BUET's Accident Research Institute (ARI) and the Road Safety Foundation proclaimed that everyday people lose fifty lakh working hours due to traffic jam and its financial value stands at 37 thousand crores every year. In addition, when the vehicles are running on their engines, the harmful Unburned Hydrocarbon is emitted in addition to the smoke, at the same time, wasting fuel or gas. In long traffic the vehicles that don't have air condition system usually turn off their engines, but the same thing cannot be said for the vehicles that possess air coolers. And most of them are private cars. According to the Nam bio, Bangladesh ranks 109 in Carbon Emissions Index. Sitting in the traffic increases the mental pressure of the drivers and the passengers, increasing the risk of road accidents. Bronchitis, headaches, dizziness, nausea, irritation in the eyes etc. - are some physical problems caused by inhalation of exhaled smoke of vehicles.

In the context of Bangladesh, emphasis should be placed on such vehicles that can accommodate most passengers in required space. In that case, the bus transportation facilities need to be increased. Currently, the use of private cars in Dhaka is increasing at an alarming rate. In order to discourage people from using private cars, authorities should increase access to public transports, encourage people to walk and should increase bicycling facilities. Retaining unfit public transports, authorities should introduce good quality vehicles so that people of all walks of life feel encouraged to use public transport. Due to the lack of such facilities, many people are using private cars in Dhaka. It is possible to reduce the dependence on the private car by introducing advanced bus service. Private car movement should be controlled by scheduling even license numbered cars in one day and odd license numbered ones in the next day and so on. In that case, traffic control will be much easier.

In order to decrease the use of private cars to control traffic jam, urgent steps should be taken to improve the quality of bus service. At the same time, to solve problems such as health hazard, Fuel waste, traffic jams, waste of time in traffic etc. the use of bicycles should be encouraged. The bike is a vehicle that is environmentally friendly and healthy. Also, cycling reduces mental stress, reduces the risk of heart attack, increases immune resistance, regulates blood pressure, and improves cardiovascular fitness. There is no separate road or lane for cycling in our country, the demand for a separate lane for bicycles has been issued for a long time.

Finally, in the light of recent experience, COVID-19 or Corona has taught us a lesson on how traffic mismanagement makes capital uninhabitable and uninhabitable. And if there is no uncontrolled car and traffic jam, it is possible to move from one place to another in Dhaka straightforwardly. The destination can be reached in the shortest time. No air and noise pollution. Future communication plans can be taken up by applying this corona's learning. The implementation of which will meet the goals of safeguarding the environment as well as reducing traffic congestion.

Professor Dr. Ahmad Kamruzzaman Majumder, Dean, Faculty of Science, Chairman, Department of Environmental Science, Stamford University Bangladesh, Founder and Director, Center for Atmospheric Pollution Studies (CAPS) and Joint Secretary, Bangladesh Poribesh Andolon (BAPA), E-mail: kamrul_sub@hotmail.com