Maryland wants to spend $5.6 billion building and operating the Purple Line light rail at a time when transit ridership is declining, and that decline appears poised to accelerate. This is an especially foolish decision when the state’s own analysis says that the light-rail line will increase traffic congestion.

Nationwide transit ridership has been declining since 2014. A recent survey of Uber, Lyft and other ride-hailing users found that one-third of them would have taken public transit were it not for these on-demand ride services. Considering the growth of such services, they alone seem responsible for more than half the decline in transit ridership.

Meanwhile, Ford has promised to have completely driverless cars - meaning no steering wheel or control pedals - in production for ride-sharing services by 2021. More than three dozen other companies, including Apple, Google, Mercedes, Nissan, Uber, Volkswagen and Volvo, are working furiously to see who can have the first shared, driverless cars on the streets of American cities. Without the driver, such services will cost far less than public transit.

This means it makes no sense for Maryland or anyone else to build new light-rail lines. Construction of the Purple Line would barely be completed before most of its potential customers are taken away by shared driverless cars.

Although the Purple Line has been presented as a solution to congestion, the state’s own traffic analysis shows it will make congestion worse. According to the state, if the Purple Line is not built, the average speed of traffic in the D.C. region will be 24.5 miles per hour in 2030. If it is built, the average speed will decline to 24.4 miles per hour.

The state’s analysis also found that the Purple Line’s goals could be accomplished at a far lower cost using buses.

The big argument used to support the Purple Line is that it will increase economic development. In fact, no light-rail line has ever stimulated the economic development of any region. Instead, Portland, Denver, and many other cities that have built light rail had to spend hundreds of millions of dollars in subsidies to persuade developers to build along the lines.

Some rail lines, such as our Metro, have led to development near rail stations that otherwise would have taken place somewhere else in the region. But even if the Purple Line could do this, why should taxpayers pay billions of dollars to shift development from one set of property owners to another?

One thing the $5.6 billion price tag doesn’t include is the cost of rehabilitating the rail line when it wears out in 25 to 30 years. If you believe large numbers of people will actually ride the Purple Line, which I don’t, then you better add another $3 billion to the cost for maintenance and rehabilitation when the Purple Line is as worn out as the Washington Metro system is today.

In the end, the Purple Line is simply a make-work project that will provide enormous profits for a few contractors at everyone else’s expense. Maryland could accomplish the same thing by digging holes and filling them up, but such holes wouldn’t increase traffic congestion or impose billions of dollars in future operating and maintenance costs on state taxpayers.

The final decision of whether to build the Purple Line falls to Transportation Secretary Elaine Chao. By rejecting the Purple Line, she can send a signal to transit agencies across the nation that the current administration will no longer tolerate wasting money on expensive rail transit systems when buses and, eventually, driverless cars can do the same work at a far lower cost.

This article appeared on Washington Post (Online) on August 15, 2017.