SAN FRANCISCO -- Motorcoach operators who attended UMA Motorcoach Expo 2012 in Long Beach, Calif., in January saw a white, double-decker "Google Bus" on the convention show floor, one of a large fleet the Silicon Valley internet giant uses to transport employees living in the San Francisco area to and from work.

Now, another much smaller high-tech firm, RidePal Inc., has launched what it calls the "Google Shuttle for the rest of us," a commuter bus service operating in partnership with Bay Area private carriers to offer employees of any company a direct ride to work on Wi-Fi-equipped buses.

Unlike Google, RidePal doesnt own or operate its own buses. Instead, it recruits tech companies that want to provide the service for employees, and then arranges for established carriers to operate the service.

Black Tie Transportation was among the first carriers to partner with RidePal, and its president sees advantages for his Pleasanton, Calif.-based company.

"We see highest demand from our other clients at the weekend, but RidePal uses our buses during the week, enabling us to make better use of our vehicles and provide steady work for our staff," said Black Tie President and CEO Bill Wheeler.

"We are also pleased to be working with a company that shares our focus on excellent customer service," he added.

According to RidePal, the shared commuter buses offer tech companies a useful tool to recruit and retain talented employees, particularly in the Bay Area, where commuters can face long hours in traffic.

Because they have Wi-Fi, the buses enable the companies to increase employee productivity. The shuttles also reduce parking needs and cut the companies carbon footprint.

The employer companies can choose to subsidize rides at any level, from zero to 100 percent. Since riders from several companies can share the same bus, no one company supports the entire bus.

Individual riders also can sign up through the RidePal website.

RidePal, which began a pilot program in the spring, appears to be catching on.

Between August and mid-September, the service logged a 50 percent increase in registered riders, from 500 to 750 passengers, and currently has employees from about 20 companies riding the buses.

It recently added three new services to Pleasanton and San Francisco from the Mountain View and San Jose areas, bringing its total to close to 20 routes.

A key to its growth has been support from such investors as Greenstart, a San Francisco green technology business incubator, which provided $25,000 and other support during its early days.

In September, RidePal announced that it had raised $500,000 in seed-round funding from investors, including 500 Startups, Amicus Capital, and Jeff Clarke, chairman of Orbitz.

Dominic Haight, the companys chief revenue officer, said the service is comparable in cost to public transit alternatives, such as Caltrain, the commuter train running between San Francisco and Santa Clara and San Mateo counties.

An unlimited monthly pass on RidePal costs about $200 for shorter runs, he said.

He said the service offers commuters distinct advantages over public transit, including all buses being equipped with Wi-Fi, bike racks and comfortable leather seats.

"The other advantage is that our routes are driven by rider demand," he said. "So they register with us, we get their home address or cross street and when they want to get to work, when they want to leave, and we analyze that information to figure out what are the best routes and the best stops to do.

"For some people the public infrastructure is very convenient, and thats great. But some people have to get all the way across the city, and when they arrive at the destination have to get all the way across another city to get to work. Our routes are generally direct."

The company plans to expand into 20 other urban areas where its research indicates theres an unmet demand for commuter shuttle service.

"People no longer live in a suburb and commute into downtown, but live in one suburb and work in another one. The public infrastructure cant keep up. We can be extremely flexible," Haight said.