When thinking about successful mass transportation in the United States, Americans will inevitably imagine big cities like New York and Chicago — a stereotype shaped by the sorry state of public transit throughout the rest of the country. But what if there was a way to bring that kind of world-renowned rail and bus infrastructure to thousands of smaller cities dotting the country?

Turns out, there is — and all it would take is the stroke of a pen.

According to a new joint study conducted by American and Chinese researchers and published in the journal Transportation Research Part A: Policy and Practice, federal funding of transit systems is the single strongest factor impacting transit ridership and availability.

The study took a look at the development of 417 urban areas in the US across 2010 to 2019, using three models to isolate and measure the impacts that different funding sources had on rider numbers and supply in small, medium, and large metropolitan areas. (The US Federal Transit Administration classifies small urbanized areas as having populations between 50,000 and 199,999 residents, while large urban areas have populations of 200,000 or more.)

Though riders in cities of all sizes benefits from federal funding, the research found that government subsidies for large cities are actually less effective than in “smaller, developing transit markets,” where they help leaner agencies expand their vehicle fleets and increase their pool of resources.

“In the largest metropolitan areas, an additional dollar generates roughly one-third as much new ridership as it does in a small or midsize city,” Kailai Wang, one of the study’s co-authors and assistant professor of Industrial and Systems Engineering at the University of Houston said in a statement.

The researchers stress that none of this diminishes the importance of funding from city- and state-governments, or of federal funding for metropolises like NYC or the San Francisco Bay Area. Rather, it highlights the major importance of federal funding for transit systems in smaller, up-and-coming cities, especially those that currently offer no alternative to driving.

Once in place, those transit options wouldn’t just benefit riders, but pay dividends to the whole city by reducing traffic congestion, curbing emissions, and offering an affordable alternative to low-income residents. Sure, it may mean diverting a small fraction of our federal tax dollars into specific cities — but for a country that currently spends more than $1.5 trillion on war every year, the US could certainly afford it.

More on mass transit: Elon Musk Says He Could Definitely Build a Public Transit System Better Than Anything In China If He Tried