When Southern California transportation gurus talk about creating more options, that’s a cue for commuters to leave their cars at home and try mass transit or bike share.

But some existing train riders — particularly those living in eastern Los Angeles County and western San Bernardino County — have found a different kind of option. Thousands are switching from riding Metrolink, a commuter rail, to taking the Gold Line light rail. Both go to Los Angeles but the Gold Line is much cheaper, offers more trains more often and less waiting.

This rail-to-rail migration from Metrolink, a locomotive-powered heavy rail line, to Metro’s suburban-reaching light rail doesn’t remove cars from the traffic-snarled freeways nor does it reduce air pollution since these commuters weren’t driving anyway.

Instead, it’s creating competition and causing friction between the two agencies that will only get worse once the Foothill Gold Line Construction Authority builds the next leg from Glendora to Montclair, creating duplication of services at three Metrolink stations: Montclair, Pomona and Claremont.

“We certainly find it interesting to place two public transportation options — rail and light rail — right next to each other at Pomona, Claremont and Montclair stations,” said Scott Johnson, Metrolink spokesman during an interview Friday.

The unusual alignment, as well as the loss of riders from Metrolink, caught the attention of the heavy rail planners at the Los Angeles County Metropolitan Transportation Authority, or Metro, which proposed a $500,000 study on how the two agencies can coexist.

According to a pre-study report released July 19, Metrolink’s most popular San Bernardino Line experienced a 7.6 percent drop in boardings from January to March as compared to the same period in 2016. The train line lost 25 percent of its riders from the Covina Metrolink station, the report concluded.

The line lost 56,620 riders during that period, according to Metrolink ridership report entitled: “Objective: Increase Ridership.” The next closest drop was on the Inland Empire Orange County Line, which saw 14,488 fewer riders for a 4 percent decrease.

Between 2014 and 2017 fiscal years, the Rancho Cucamonga Metrolink station experienced a 25 percent drop in daily boardings, according to the San Bernardino County Transportation Authority. The reasons include: a new $4.50 parking charge, lower gas prices and the elimination of a popular rush-hour express train.

The losses from the Covina Metrolink Station relate to the proximity of the Gold Line. The APU/Citrus College Station is four miles from the Metrolink station. The report concluded “a significant number of Metrolink riders that previously used the Covina Station has switched to the Gold Line service, opened on March 5, 2016.”

Metro is investing close to $1.5 billion to build the 12.3-mile extension of the Gold Line to Montclair. Most of the new riders will come from the Inland Empire and board at Montclair, Pomona and Claremont, sources said, the same stations where Metrolink picks up passengers.

Once completed, Metro expects more Metrolink Inland Empire riders to make the switch to light rail. While this sounds like a win for Metro, it’s not because Metro is paying a large chunk of Metrolink’s budget and must justify both systems. For 2016-17, the L.A. County sales tax-supported agency will contribute $71.7 million or about 30 percent of Metrolink’s operating budget.

When Metro planners said one of the study objectives was to recommend changes to the Gold Line extension project, the simmering from the Gold Line Construction Authority nearly reached a boiling point. The issue became so hot Metro’s Planning and Programming Committee postponed the study until September and declined to discuss it at the July 19 meeting.

Instead, Metro has asked the CEOs of the Gold Line Construction Authority, Metrolink and Metro to meet about what the study should examine.

“The Gold Line Construction folks are getting a little nervous. They think that we will dictate to them how to build their Gold Line,” remarked Metro board member Ara Najarian at the meeting after the item was pulled. “Let’s remove the anxiety that has begun to develop between all those agencies,” he added.

Construction Authority CEO Habib Balian was unavailable for comment. The Authority directed calls to Sam Pedroza, vice chair of the construction authority board and a member of the Claremont City Council.

He said it was a good thing some Metrolink riders lived close enough to choose the Gold Line. One reason was cost, he said.

An unlimited, one-way ride on the Gold Line costs $1.75. Riding Metrolink from Covina to Union Station costs $7.75. A regular, adult monthly pass for Metro is $100, while a monthly pass from Covina to Union Station on Metrolink costs $217 and $371 from San Bernardino.

While Pedroza said the two forms of train transit are not competing, he advocated Metrolink focus more on taking commuters into L.A. who can afford it, riding on larger, double-decker trains with seats that are more plush and making fewer stops. For a lower ticket price, the growing Gold Line offers more frequent service, stops at more places including destination cities such as Pasadena, and runs more nighttime trains.

“Metrolink is still going to have their core ridership, people who travel from the Inland Empire to downtown L.A. But at the same time, Metrolink is a system that needs to reinvent itself,” Pedroza said.

Johnson said Metrolink had to terminate express trains because they were making other trains late. It is thinking of running some trains that skip Claremont to quicken the ride to L.A. Pedroza said one future option is to link with the coming high-speed rail.

“The two different agencies can work together to make both successful,” Johnson said. “We all want people to stop driving. We all want to see the air quality improve.”