My Solution.

I always think that when there is urgent situation, it is the fastest way to take a taxi.
However, it is hard to get a taxi where people do not walk a lot or suburb. I have an experience that I want to try take a taxi but it is hard to find. At that time, I thought to make an app about 'catching taxi'. This works that to tell the taxi driver about current location of passenger. After that, taxi driver will go to that location to pick up the passenger. It is good way to save time each other and make more comfortable to passenger get a taxi.