Bus commuter schedules no longer reflect demand

Though by all accounts Golden Gate Transit's commuter bus system is quite popular, it is increasingly out of touch with the commute times of Marin's modern workforce. Marinites leave for work later, but GGT continues to operate with early-morning service. FiveThirtyEight recently took Census data and determined which metropolitan areas get to work the latest. The San Francisco metro area, of which Marin is a part, got fifth on the list, with a median arrival time of 8:17am but a 75th percentile arrival time of about 9:30am. The bottom of the range is about 7:45am.

Just after reading this, reader John Browne, a frequent rider of the last Route 18 from Kentfield, tweeted:

It turns out John Browne is right.

Using the same Census data FiveThirtyEight used (though without the math to convert it into the ranges author Nate Silver did), I plotted out the average departure times for Marin commuters taking all modes to work. Transit commuters leave work at roughly the same rate as others up until 9am:

Yellow is transit.

The proportion of transit riders leaving home between 9 and 10 stays down after the drop from 8:30 to 8:59 while other modes pop back up.

A glance at the span of service for Marin's commute buses makes it easy to see why that might be. On average, the last Marin stop for a Marin commuter line is about 8:27, while the average last departure is a bit earlier at 8am. In other words, if you want to get out of Marin by bus, you're probably going to have to leave home before 8 or 8:30, and that's exactly what shows up in the Census data.

GGT should reexamine the county's travel demand and which final buses are the most crowded and aim to add service to those lines later in the morning. Adding to service span will scoop up riders that want to leave later, and can also give earlier riders the peace of mind that they can leave later if needed, helping shore up ridership earlier in the morning, too.

It's not just tech workers that are leaving later in the day, it's Marinites in general. Our transit system should start scheduling for that.