Drivers getting out of town on this Fourth of July weekend will pay the highest gas prices since 2008, but transit riders are also feeling the sting of new rate increases in major cities like Boston, St. Louis, and Washington D.C.

But even with semi-regular fare hikes, transit systems still lose money. Revenue from fares isn’t enough to cover rising costs, like labor, fuel, expanded services, and infrastructure maintenance, even though ridership in 2013 was the highest it’s been in nearly six decades. 

“The actual fare rider could be paying half of the rider cost, sometimes two thirds of it,” says Mitchell Moss, director of the NYU’s Rudin Center for Transportation.

Nationally, fare revenues covered only 33 percent of the operating cost of all transit systems in 2012, according to the National Transit Database.

But raising fares is tricky.

“When you increase fairs, it tends to discourage ridership,” says Steve Schlickman is with the Urban Transportation Center at University of Illinois at Chicago. “If you increase fares too much, you discourage so much ridership that you really don’t have an increase in revenue.”

It falls to cities and states make their transit systems’ deficits. But the Department of Transportation is warning that without intervention from Congress, a critical source federal funds for many transit and highway projects will run out of money later this summer. 

Here’s a look at which cities bring in the most revenue from transit fares per rider, and which cities are planning to hike their fares this summer: