Is it better to use the car or public transport?

Is it better to use the car or public transport?

We are going to analyse which is the best way to travel around the city. The choice is between using a car and using public transport. We will be focusing on short run trips and we will point many aspects like costs, time costs and traffic accidents. In spite of many important issues has been treated here, pollution not will be treated since we cannot conclude if car is worse than public transport in terms of pollution (that just rely on technology of the transport, so is not equal for each country). Our data is from Buenos Aires, Argentina.
First thing we have to take account is the costs of traveling by car or public transport. Once you get on the bus, you have to pay at least 6 ARS if you do short distance trips. If you are planning to do your short-distance trip by driving a car, you have to pay for fuel, which is $20 per liter. Furthermore, you have to spend on average 15 ARS per hour to park your car. Definitely and absolutely, our claim is to say that public transport is cheaper than using the car.
For another thing, in cities like Buenos Aires you may spend 50% more time if your journey is by public transports instead of doing it by car. However, you need to take account that cars have a negative impact on road congestion: Since the traffic flow increases, the average speed that any car could drive decreases. Therefore if everyone drives a car, they will be slowed down. Many cities have this problem, for instance, in Mexico city drivers spend 97% extra time to arrive at their destinations as a result of traffic congestion.
Another point worth mentioning is that the more traffic congestion the more likely to occur traffic accidents. So if you take the bus, you are reducing traffic flow and hence traffic accidents probability too.
To sum up, driving by car is more expensive but faster than public transport unless the road is congested (remember that you can use metro). Reducing car usage, the rate of traffic accidents may decrease. Social sciences cannot conclude anything unless you have reliable statistics to use. Is up to you whether if you choose to start a journey by car or not.

Please note that the only one purpose in this paper is improve English writing. I am not intending to prove or conclude any empirical fact. I would have put the source at the bottom of the essay if that had been the goal.

Thank you!