This May, the Houston-Galveston Area Council surveyed riders on trains and buses in the Houston region. They completed 12,000 surveys, including 1,136 on METRORail (resulting in a +/- 2.9% margin of error). Some of the more notable findings (pdf):

Rail has attracted new transit riders. 49% of METRORail riders had a car available to make their trip; 41% said they started using transit because of the rail line. Notably, rail has also attracted more people to buses: 12% of METRO local bus riders said they started using transit because of the rail line.

About half of rail riders made their entire trip on rail. 54% of rail riders transfer to or from a bus. That’s remarkable for a line only 7.5 miles long: 68% of Houston bus riders transfered on their trips. But it also points to the importance of linking light rail and bus lines well.

Rail serves all income levels. Like local buses, METRORail serves as a transportation safety net for those who can’t afford to drive. 40% of riders have household incomes below $32,000. But 20% have household incomes over $81,000, compared to only 5% on METRO local buses.

Pedestrian-based transit works in Houston. 28% of METRORail riders park-and-ride (I’d estimated 30% based on boarding data); 8% are dropped off by car. That leaves 2/3 of riders who get to the train (or to a bus that got them to the train) on foot. On average, they walked 2.4 blocks — about 1/8 to 1/4 mile, depending on the part of town — to a station.

Rail is serving non-work trips as well as work trips. 35% of METRORail riders are headed home; 30% are headed to work. That means that no more than 2/3 of trips — and probably more like 1/2 — are home-to-work or work-to-home. 13% of riders are bound for school; 8% are going to the doctor; 5% are running errands; 4% are on a recreational trip. Only 65% of rail riders ride 5 or more days a week; almost 10% ride less than once or twice per month. METRORail is serving a lot of commuters. But it’s also taking care of all the other kinds of trips people make. Compare that to METRO’s park-and-ride buses, where 90% of the trips are home-to-work and vice versa and 85% of riders ride at least 5 days a week.

Bikes expand the reach of transit. Bike riders ride on average 2.2 miles to a station. Thus, there are many more people within biking distance of a station than within walking distance. However, only 0.6% of rail riders arrive by bike. That’s probably due in part to restrictive bike policies (no bikes on trains during rush hours) and limited bike racks at stations.

High quality bus transit can attract riders who would not otherwise take transit. Some statistics for the suburban park-and-ride system, which uses HOV lanes to provide frequent, reliable, fast, nonstop service: 50% of riders have household income over $81,000, 87% had a car available for the trip, and the average rider drove 6.4 miles to a park-and-ride. (A reminder, though: high quality bus isn’t cheap: the park-and-ride system cost three times as much to build as METRORail even though it has the same ridership, and has much higher operating costs.)

The ridership numbers alone make the case for the Main Street Line: it’s carrying more people per mile (and thus per dollar invested) than any other modern light rail line in the United States. But this survey data amplifies that: the Main Street Line works because it serves more than just home-work trips, because it stops within walking distance of important destinations, and because it serves the poor and the prosperous. The Main Street Line is a good model for successful urban transit; it’s no accident that the University, Uptown, North, East End, and Southeast lines will follow its example.