Dave Toister had been waiting at the Rohnert Park park-and-ride only for a few minutes when his colleague, Sam Amin, rolled up in a Toyota Prius.

Toister jumped into the passenger seat and, before Amin drove off, the carpool buddies repeated a daily ritual — they pulled out their smartphones and logged their route into an app called Carma.

The publicly funded program that matches drivers with people looking for rides is designed to get cars off the road and reduce traffic and air pollution.

Amin merged onto Highway 101 during the morning commute. Traffic already was starting to back up through downtown Santa Rosa, but Amin and Toister flew past in the carpool lane, chatting about the latest alternative fuel cars.

Less than 20 minutes later, they arrived at the Airport Business Center just south of Windsor, where they work in Kendall-Jackson's information-technology department.

“Alone, it takes 45 minutes to an hour to get to work,” Amin said. “It's much faster when we carpool. Plus, we can share the cost.”

The two have been carpooling together for a few years and decided to try using Carma in November.

Occasionally, they use the app to find rides at lunch time, but they say that there are not yet enough people on Carma — about 1,000 users are from Sonoma County — to be able to walk out the door and find a ride.

“There aren't a ton of people on it,” Toister said. “That's the only downside.”

Carma administrators hope to change that. On March 3, they will be rolling out an updated version of Carma that is simpler to use. The free app currently is available on Apple's App Store, Google Play and here.

There are incentives to join — a $5 bonus for signing up, $10 for the first car trip, and $50 for 50 shared rides. Carma staff have been promoting the service at park-and-rides and local businesses.

With a smartphone, a driver can see other Carma users in the area who are looking for a lift, and potential passengers can see where drivers are headed. Users can message each other and meet up to share a ride.

When they reach their destination, the passenger can send the driver a nominal payment via Paypal to cover the cost of gas. Driver and passenger can rate each other, much like the ratings for buyers and sellers on eBay.

The Metropolitan Transportation Commission is implementing the program in Sonoma, Marin and Contra Costa counties with a two-year, $1.5 million grant. The Sonoma County Transportation Authority is leading the initiative locally in partnership with the non-profit Climate Protection Campaign. The company that built the app is based in Ireland.

Carma is different than for-profit ride-sharing services like Lyft, Sidecar and Uber. Those services are regulated by the state Public Utilities Commission, and their drivers work for fares or tips like taxi drivers.

Carma works more like the casual carpooling system that has developed between the East Bay and San Francisco, said Brant Arthur, local project manager for Carma.

“We're connecting people so they can share rides,” he said. “It's about access to transportation. You don't have to own 4,000 pounds of glass and steel to get around.”

But you do have to own a smartphone, or at the very least, a computer with an Internet connection.

Carma helps government agencies achieve their goal of reducing greenhouse gases, said Sonoma County Supervisor Mike McGuire, a director of the transportation authority. At least 60 percent of all greenhouse-gas emissions are caused by auto traffic.

In two years, Carma commuters have logged 25,000 shared miles and reduced carbon emissions by 13 tons, McGuire said.

Typical users are Sonoma State University students and commuters along the Highway 101 corridor who work in business parks between Petaluma and Windsor.

“When it comes to the big picture of reducing daily car trips, this helps reach that goal,” McGuire said. “We have to be focused on making carpooling more accessible for Sonoma County residents.”

©2014 The Press Democrat (Santa Rosa, Calif.)