The transportation network is essential to the economic life of the whole population of Minnesota. It is exactly the kind of necessary, non-optional public good that justifies the use of State power for its construction, operation and maintenance.
Every resident of Minnesota depends on the transportation network: if not directly, to get to and from work or school, then indirectly as a consumer of services and goods that travel over the network. The costs of transportation are passed along in the prices of everything from soup to life insurance. Looking at the Metro from a more rural area, it may be tempting to imagine that 'I don't use it, so why should I have to pay for it?' It is important to remember that we all use it, and it is in all of our interests to have it working as well as possible.
Every day, Minnesotans waste thousands of hours in the repetitive and utterly pointless task of driving to work. If even 10% of these unfortunate souls could have the option of leaving the car at home and hopping on the train, just think how much more room there would be for your Suburban.