Local and regional transportation planners often consider two distinct options—people driving to and from work, or people using mass transit. But the rise of shared transportation modes—including ride-sourcing services such as Uber or Lyft, car-sharing companies such as Zipcar, and bike-sharing programs—is rapidly changing that by creating new options for commuters, according to panelists at a recent conference in Washington, D.C., sponsored by the Eno Center for Transportation, a Washington-based nonprofit charitable foundation seeking improvement in transportation and its public and private leadership.

The conference participants, who included a range of experts from private sector transportation companies and public sector agencies, said it is imperative for government transportation officials to figure out how to adapt to changes in the industry.

The answer, they agreed, is to move to what Timothy Papandreou, chief innovation officer for the San Francisco Municipal Transportation Agency, called a “shared-mobility ecosystem.” Such multimodal systems would combine public and private resources and integrate sharing options with public transit rather than compete against one another. All these transportation choices could be bundled into one common smartphone app, allowing commuters to select the option that is cheapest or most convenient, or both—or to combine multiple options in one trip for optimal efficiency.

“We really have to move forward and past this binary policy system we have now,” said Papandreou. The explosive growth of Uber and other providers, and their rapid embrace by the public, has caught planners by surprise, he said. “The demographic shift and culture change have been much faster than we thought was physically possible.”

Moving rapidly to develop systems incorporating shared transportation will help cities reduce congestion, panelists said, while also filling in gaps in transit systems that make it difficult for residents of underserved areas to get around.

The ultimate benefit to cities is to “dial down the need for a car,” said Sharon Feigon, executive director of the Shared-Use Mobility Center, a Chicago-based nonprofit that fosters collaboration between the sharing economy and transit agencies.

Feigon cited a study by the American Public Transportation Association that found shared transportation modes tend to complement public transit systems rather than compete with them. The more that commuters use sharing options, the more likely they are to use public transit, and the less likely they are to own a car. In addition, use of ride-sourcing services such as Uber tends to peak at night and replace car trips for social purposes, while public transit use peaks during commuting hours.

Andrew Salzberg, Uber’s global mobility policy leader, said ride-sourcing services provide a safety net for users of public transit, helping them with situations such as having to spend an unexpected late night at work. The New York–based Salzberg said he is one of those multimodal commuters, even though he gets free rides from Uber as a perk. “I use the subway during the day,” he said. “It’s more convenient.”

But the panelists also noted that transit agencies face major challenges in fitting private sector sharing modes into an integrated system. For one, users of shared mobility are accustomed to services they can order via smartphone—an option not offered by most public transit systems.

“A lot of the challenge is bringing transit agencies up to speed,” said Regina Clewlow, director of transportation research and policy at RideScout, an Austin-based startup that has developed a mobile app for integrating public transit and shared options. “The private companies are bolting ahead at lightning speed.”

What happens to the use data generated by an integrated multimodal system is another tricky issue, panelists noted. Private companies generally have kept their information proprietary to protect their competitive advantage, but some sharing will be necessary in order for planners to optimize the system.

Panelists also noted that local governments need to alter urban planning to facilitate shared transportation options. Emily Castor, who leads Lyft’s efforts to partner with transportation agencies, said planners must create more space for curbside pickup and drop-off. Papandreou went further, saying planners need to convert existing parking spaces from use by private vehicles to shared-mobility use.

Papandreou also urged cities to create incentives for use of multimodal systems rather than private cars. “We should start looking at developments with zero parking,” he said.

At the same time, he said, cities have to look for ways to make shared options more affordable. Even in San Francisco, one of the leaders in shared transportation options, daily use amounts to only about 2 percent of local trips, he said. “It’s still too expensive to use for most people,” he said.