Well I think I talk about the problem too much, now is the time to move to the solutions. But then how? First we have to propose research methods in which we will further understand the problem better and the way to resolve it as well. Research method itself is "a process used to collect information and data for the purpose of making business decisions", reviewed by businessdictionary.com. Or in our case more relevant as the purpose of making better solutions.

For the common research methods we have literature research, surveys, interviews, focus groups, case study, and many more. A literature search involves reviewing all readily available materials. These materials can include newspapers, magazines, reports, on-line data bases, and any other published materials. Mostly finding data from the internet is the fastest and most convenient way to get information. It is a very inexpensive method of gathering information, although it often does not yield timely information.

For survey, it is basically giving a group of people series of same questions aiming for different answers in a large scale and short amount of time. Survey can be in form of telephone in which the interviewer already preparing for the questions but allowing for some opinion probing, mail, even though it takes longer time to complete, or the most famous one is email and internet survey. It is relatively new but the fastest and the most cost effective way.

For interview, it is a way to get-in-depth and comprehensive information. It involves or more interviewing other person for detailed information that they usually will not answer in other survey methods. Typically, an interviewer will ask questions from a written questionnaire and record the answers verbatim.

While a focus group is used as a preliminary research technique to explore peoples ideas and attitudes. It is often used to test new approaches (such as products or advertising), and to discover customer concerns. A group of 6 to 20 people meet in a conference-room-like setting with a trained moderator. The moderator leads the group's discussion and keeps the focus on the areas they want to explore.

Lastly, a case study is an in depth study of a particular situation rather than a sweeping statistical survey. It is a method used to narrow down a very broad field of research into one easily research-able topic. Whilst it will not answer a question completely, it will give some indications and allow further elaboration and hypothesis creation on a subject.
Then a unique research method can be done by mixing some common methods together into a flexible yet useful way. For example, we can do mixing between focus group and personal interview to get a general sample and also in depth answers from several people.
However for our particular problem of too many vehicles, me and my group decided to use literature research as the background data, and internet survey as well as case studies for further research. Why, because it required less effort yet encompassing broader sample.
So, until next time people! :)
References :
http://www.businessdictionary.com/definition/research-methodology.html
https://www.statpac.com/surveys/research-methods.htm
https://explorable.com/case-study-research-design