For decades, the transit industry has tried to convince Americans that they have a moral obligation to subsidize public transit and to spend billions of dollars building new rail transit lines. Yet the reality is that transit is increasingly irrelevant, as Atlantans have shown by deserting transit in droves.

Federal transit data show that Atlanta transit ridership has declined every year since 2009 and was lower in 2014 than in any of the previous 30 years. Since the region’s population has grown by nearly 150 percent during those years, per capita transit ridership has dropped by more than 60 percent since 1985.

Data are not yet available for all of 2015, but in the first nine months of last year, MARTA carried only 0.9 percent more riders than in the same period of the year before. Nationwide, transit ridership dropped by 1.7 percent in the same period.

Remember all those Millennials who weren’t going to drive? Many of them bought cars as soon as they could afford to do so. In the year ending in November 2015, nationwide driving grew by 3.6 percent over the previous year, the fastest rate of growth in recent decades. While driving declined briefly after the 2008 financial crash, that recession-related decline was only temporary.

Originally, we were supposed to subsidize transit to help people who couldn’t drive or couldn’t afford cars. But according to 2014 census data, just 3.5 percent of Atlanta-area workers live in households without cars.

How do people without cars get to work? Nearly 24 percent drive alone (presumably in employer-supplied cars) and 20 percent carpool. Less than 36 percent take transit, showing that transit doesn’t even work for most people without cars.

More recently, we’re supposed to subsidize transit to get cars off the road, save energy and reduce greenhouse gas emissions. Yet transit uses about the same energy and emits about the same greenhouse gases to move someone a passenger-mile as a car does.

Moreover, building rail transit lines requires huge amounts of energy and greenhouse gas emissions. Instead of building more rail lines, we could more effectively save energy by simply giving people Toyota Priuses.

What is MARTA’s answer to this? It wants to spend billions building light-rail lines, commuter-rail lines, and expanding the existing MARTA rail system.

Unfortunately, the high cost of rail transit is one reason Atlanta transit ridership is declining. Rail lines only reach a few places and can’t survive without an effective bus system. Despite rapid population growth, however, MARTA has cut bus service more than 11 percent since 1985.

It might be said that MARTA practices transit apartheid, building rail lines to middle-class neighborhoods while cutting bus service to poor black neighborhoods.

Transit as we know it isn’t dead yet, but it will be as soon as self-driving cars are perfected, which will happen in the next five to 10 years. Companies like Uber and Lyft are already planning to have fleets of shared, self-driving cars on the road.

Counting all subsidies, it costs almost four times as much to move someone a mile by transit as in an automobile today. Once shared, self-driving cars are available for those who can’t or don’t want to drive, why will we need transit at all? Rail lines will become urban white elephants and, if the streetcar system is anything to go by, Atlanta already has enough of those.

Instead of planning even more white elephants, MARTA should figure out how it will compete or even survive in the coming era of self-driving mobility.