In 2010, only 58 percent of those who worked in Orange County lived in Orange County; among the remainder, 20.5 percent lived in Los Angeles County, 11.8 percent in the Inland Empire, 5.2 percent in San Diego County, and 27.8 percent commuted 25 miles or more
That 20.5% of Orange County's workers come from Los Angeles County, while 11.8% come from the Inland Empire, is a rather reasonable thing in and of itself. Los Angeles, after all, is quite a bit larger than Riverside and San Bernardino Counties. But it's notable in light of the poor service which Orange County sees for workers from Los Angeles compared to that which it sees for those from the Inland Empire. Metrolink is, after all, notable for providing one of the very few suburb to suburb lines in the country with the imaginatively named Inland Empire-Orange County Line. As Metrolink itself has noticed, job growth in Orange County has led to the OC and IEOC lines being protected from ridership losses (page 86):
Analysis of the regional economic recovery have shown robust job growth in south Orange County, the South Bay and the West Side, while downtown Los Angeles job growth has been relatively flat. This trend was further reinforced by government employee furloughs (a major job sector for downtown Los Angeles). This is reflected in ridership growth on the Orange County and IEOC Lines while other lines have been flat or declining.Additionally, while downtown Los Angeles has been shedding jobs, it's been adding housing, to the extent of 20% of all new housing in Los Angeles County (though this is also an indicator of how bad the rest of the county is at permitting new housing). Meanwhile the chief worker importing cities of Orange County; Anaheim, Santa Ana, Irvine, and Orange; are all served by Metrolink directly from Los Angeles. Now, surely in a rational world twice the potential ridership market (workers commuting into Orange County) would merit at least a comparable level of service. Unfortunately, we live in the land of Metrolink.
The IEOC Line currently offers five daily arrivals in Irvine prior to 9:00 AM. The 91 Line serves Fullerton and Buena Park in the north with an additional three for a total of eight peak frequencies from the Inland Empire to Orange County. From Los Angeles, Metrolink offers only one single, solitary train before 9:00 AM (though a second arrives in Irvine at 9:08). If you're a monthly pass holder and your destination is one served by Amtrak, there are two additional trains that you can take on the Pacific Surfliner, but this is far from ideal and doesn't help those who are heading towards a Metrolink only station or are coming from Norwalk/Santa Fe Springs, which is not served by Amtrak.
If we extend the definition of peak to arrivals by 9:30 AM for Los Angeles and Irvine, in order to account for intermediate destinations (the average trip being somewhat less than the distance from Irvine to Los Angeles), the June 2011 data shows 440 reverse peak AM riders on the two reverse commute trains (600 & 682) out of a total of 3,542 peak riders (601, 603, 605, 607, 681, 683, 685 additional). 12% of the ridership is less than the 22% of trains that those two trains represents, but they're not quite as advantaged as the peak direction trains. Neither is in an early morning time slot such as the best train, 601, which, arriving at Union Station at 6:40 AM, carried an average weekday load of 648 passengers. Train 600 stops at Irvine, preventing it from carrying any commuters further to Oceanside, and while 682 does continue down to Oceanside and has the higher ridership of the two, it arrives at 10:10 AM, making it an off-peak train for that destination rather than reverse commute. Reverse commute ridership is also depressed by the poor options for getting home: The last northbound Metrolink currently leaves Irvine at 5:10 PM and Amtrak really isn't a substitute even where it can be taken: The only two Amtrak trains after that are at 7:38 and 9:59 PM. Even rush hour traffic on the 5 isn't bad enough to justify that long of a wait for the next train.
It's clear that, despite Metrolink's poor offerings, there's already demand for reverse commute service on the Orange County Line and that, should it be adequately offered, it has the potential to result in substantial ridership gains. Indeed, given the current strong financial performance of the Orange County Line (revenue recovery of 73.1% even including the lackluster Fullerton-Laguna Niguel runs), it's possible that a successful reverse commute program could bring the Orange County Line up to the rare status of an operationally profitable commuter line. As the slots and equipment become available, therefore, Metrolink should prioritize adding reverse commute service from Los Angeles to Laguna Niguel and Oceanside.