There are several ways this question could be answered. One way to answer this question is to say that transportation systems, schools, and banks are all examples of groups that are subject to government regulation. Schools have many rules to follow that are established either at the state and/or local level. The banking industry is also regulated. This regulation occurred because of the failures that occurred in the banking industry during the Great Depression. Transportation systems are also subjected to rules and regulation established by the government. Airlines have federally mandated taxes that are added to fares for purposes of security. Airline mergers must get government approval before occurring. Local transportation systems are also generally under government control. They receiving funding from the local or state government and must follow rules and regulations that exist. Sometimes they must get approval before they can raise fares.
Another way to answer this question would be to say that schools, transportation systems, and banks are institutions that provide a service to the communities they serve. Transportation systems are designed to move people around a city quickly. They allow people to travel to different parts of a city without having to worry about driving and parking a car. By using buses or subways, these systems allow many people to be transported throughout a city or region. Schools also provide a service to the communities they serve. The schools certainly educate the children. Schools also may fulfill other roles such as providing recreational and social activities for their communities. Banks allow businesses and people to have a place where they can keep their money safe. The banks also provide loans to businesses and to individuals that allow for investment in the local community. This may lead to the creation of jobs and the growth of local economy. These groups could be viewed as service-oriented institutions.
While there are many ways to fill in the blank line in your question, I have provided you with two options to consider.