Earning money is hard, but you need to do it, so can buy some food for your family. As a taxi driver, you do understand that you earn more if there are more customers that are trusting you with their lives. You need to ensure their safety to gain trust.
In this game, you would need to drive as fast as you can till you reach the finish line. But, you need to ensure the safety of the customer, so try to drive safely or they might get scared and get angry at you. If that happened then you failed that level. You'll earn money if you manage to get them to safety without angering them. You can use the money to upgrade your taxi.