Which Came First—The Problem or the Solution?

Which Came First—The Problem or the Solution?

In the 1950s，a federal program for mass transit was proposed as a solution to urban congestion.Subways and buses were presented as a more efficient means of transportation than private cars.In the late 1960s，environmental protection was the word of the day，and mass transit advocates peddled subways and buses as a way to reduce automobile pollution.Then with the OPEC oil embargo of 1972，Washington's attention was riveted by the energy crisis，and mass transit was sold as an energy-saving alternative to private automobiles.Was this a case of three problems for which mass transit just happened to be a solution，or a constant solution adapting to a changing problem?(https://www.daowen.com)