Let Uber, Lyft, and those guys manage the world of the cab or car service.

Today, startup Moovit — whose headquarters city of San Francisco boasts the legendary cable cars — has raised $50 million to help people who depend on subways, buses, and trolleys.

A user enters a starting point and a destination into the free Android, iOS, or Windows Phone app, and a variety of public transportation routes are presented. When one is selected, Moovit will provide arrival times, based on crowdsourced data from users. And, in case you’re unfamiliar with the territory, the app lets you know when your stop is approaching.

How does a free app focused on a public system make money?

“Right now our investors want us to focus on global expansion and growing our user base,” CEO Nir Erez told VentureBeat via email. “So, generating revenue is not our focus at this time.”

The company, which the Wall Street Journal called “Waze for public transit,” says it currently has a community of 15 million transit riders, double its size of six months ago. It currently supports public transit in over five dozen U.S. cities, and more than 500 localities worldwide.

The new funding, Erez said, will be used to “refine and expand product features, and to grow our community of users globally.” Previously, the company raised $31.5 million.

One of the investors in this Series C round was BMW i Ventures. Why would a car company want to promote public transportation?

Erez told us that BMW and other companies “share our community-powered mission,” and want to help expand a service supporting local transit agencies. BMW also manufactures public transportation vehicles, and some of its car navigation systems include public options.

Main competitors, Erez said, are Google Maps, CityMapper, and TransitApp.

“Our biggest differentiator is we use crowdsourced data from our users in addition to high-quality public transit data,” he told us.

In addition to BMW, this round of funding came from Nokia Growth Partners, Keolis, Bernard Arnault Group, and Vaizra Investments, with participation from existing investors BRM Capital, Gemini Partners, and Sequoia Capital.