This is a personal assignment that only you can complete. However, we can provide some guidance to help you. This is an example of a letter with these specifications:
Dear Minister of Transport,
I am writing this letter because I value the quality of life in my town, and I see that this is threatened by the increasing number of cars that we find in the centre. I believe that using cars is not the right way to approach transportation in our community. Making all city centres car-free would bring many benefits, as it would allow people to walk and cycle easily, improving their health and lowering their stress.
It is a known fact that many accidents occur in cars, and that these often affect young people who do not have much experience driving. This would also benefit the environment, as cars can cause both noise and air pollution, decreasing the quality of live of people who live in the centre, as well as those who visit it. I hope you take my letter into consideration and that you make the appropriate changes.
Thank you,
John Smith