Starting in 2011, the FTA created a new class it calls “hybrid rail.” While high-cost, low-capacity rail is a hybrid between light and heavy rail, the FTA is referring to a hybrid between light rail and commuter rail.
Most hybrid rail lines had originally been considered commuter rail because they shared tracks with freight trains or used former freight lines, but instead of just operating during rush hours they operated during the same hours as light rail–typically about 16 hours a day. Frequencies might be about half those of light rail: four times an hour instead of eight during rush hours and twice an hour instead of four times the rest of the day. Rather than being powered by electricity or having a Diesel locomotive tow unpowered passenger cars, hybrid rail lines use Diesel-powered passenger cars that can be operated in trains of two or more cars (usually called Diesel-multiple units or DMU).
As of 2012, the FTA classed four lines as hybrid rail: Portland’s Westside Express, Austin’s rail line, New Jersey’s River line, and a line in North San Diego County. Because they mostly use existing tracks, construction costs were low. While the River line cost about $40 million per mile and the North San Diego line cost about $22 million per mile, the Austin and Portland each cost under $10 million per mile. On the other hand, ridership on all four lines is extremely poor, under 1,000 round-trips per day on the Austin and Portland lines and under 5,000 on the New Jersey and San Diego lines.
The railcars used for these lines typically have close to 100 seats and room for another 50 or so people standing. On average, they carried 33 people in 2012. According to the American Public Transportation Association, the average speed of hybrid rail in 2012 was 23.6 miles per hour.