Passenger rail service between Westbrook and Portland has the possibility of transforming the region. It would affect not only people’s decisions about transportation, but also where they choose to live and work, as well as development and investment patterns for decades to come.

And not surprisingly, such a game changer wouldn’t be cheap. According to a feasibility study released this week by the New England Passenger Rail Authority, it would require about $100 million in infrastructure investment, including upgrading existing rail as well as buying the trains themselves.

This study was presented not as a proposal, but as a “conversation starter,” according to NEPRA’s executive director, Patricia Quinn. That’s a conversation worth having, and one that we hope includes improving our existing public transportation system in ways that can expand to move more people to more places without waiting for infrastructure to be built or spending anything like $100 million.

For instance, Greater Portland Metro, the regional transit system with routes into Westbrook, Gorham and Brunswick, delivered more than 2 million rides last year, which was a record. Its budget for this year is a little over $11 million. You could almost double the system’s budget with a tenth of the investment it would take to put a single rail line between two adjacent communities.

Metro has made smart decisions in recent years that expand regular ridership, including contracts with Portland Public Schools, the University of Southern Maine and Maine Medical Center. They are also investing in upgrades to the payment system, so riders pay with their phones instead of struggling to find exact change, and they provide real-time information about when buses will arrive and onboard Wi-Fi.

Increasing the number of riders deals with half of the chicken-and-egg problem faced by all transit systems. When there are fewer riders, service is less frequent. And the expectation of longer waits means that fewer people will choose to ride. But if potential riders know that service is reliable and frequent, they will be more willing to ride transit.

There are advantages to rail. Trains don’t get stuck in traffic, and they can be faster than a motor vehicle. But there is no reason to wait until a commuter rail system can be born for Maine cities to build a public transit culture, where people don’t always assume that their car is the best way to get around.