Image by Rich Renomeron licensed under Creative Commons.

As part of the transit network, bikeshare is often considered to be a reliable alternative to Metro. There are certainly commuters who have made the choice to bike instead of taking the train. However, bikeshare really isn’t a good substitute for Metro when trains get delayed and riders can’t plan ahead.

Bikeshare: A substitute for Metro?

Existing research (here, here, and here) has shown that bikeshare only substitutes for Metro in dense urban areas. Users making a short trip inside the city have no problem biking instead of riding the train. We don’t see this substitution on the periphery of urban areas, where bikeshare actually complements Metro by serving as a “last mile” connection — users who are far from a Metro stop can bike to the Metro instead of driving to their destination.

CaBi bikes outside of the Van Ness metro station. Image by thisisbossi licensed under Creative Commons.

Given WMATA’s ongoing reliability issues, it’s worth diving a little deeper into the idea that bikeshare can replace Metro for quick trips. Taking a bike is easy enough when you make that decision before you leave home or work. However, it’s not clear that many Metro riders view bikeshare as an alternative option if they haven’t planned in advance.

Put simply, when riders show up at a metro stop and see that their train is delayed, do they ever hop on a bike?

Modeling bikeshare usage

This question can be answered with Capital Bikeshare trip data and information on delays scraped from the WMATA website. Using data from 2015 through 2017, I added up the number of rides that start at each bikeshare station in any given 20-minute period. I only looked at the 281 bikeshare stations within a half-mile radius of a Metro stop, figuring that customers are unlikely to go any farther to find alternative transit. These stations are show in green on the map below.

Image by the author.

Using a regression analysis, I tested whether the number of trips from each bikeshare station increased at all when a Metro delay occurred on a line within a half-mile radius of that station. My analysis also controls for the temperature, precipitation, snow accumulation, day of the week, and hour of the day.

Here are the results

In short, no one really turns to bikeshare when their train is delayed. I found no significant change bikeshare usage when a Metro incident occurs, or in the period right after the incident. This holds even when looking only at the impact of large delays, and when looking at the bikeshare stations that are closest to a Metro stop.

There are two aspects of the DC transit system that might explain these results. First, Metro is delayed so frequently that DC has developed an understanding culture — "I was stuck on the Red Line" is an evergreen excuse, so people don't often feel pressured to find alternative transit when delays occur. Plus, the average Metro incident delayed riders by just eight minutes, which is well within the window of allowably late.

Second, there are logistical barriers to biking. Would-be riders need to be travelling light and wearing the right shoes, and carrying a helmet. Most need to know that their route isn’t all uphill. Infrequent riders need to feel comfortable cycling down the street at busy times of day.

Given these challenges, rideshare can be much more appealing than bikeshare as an alternative means of transportation when Metro gets delayed. Rideshare prices seem to surge when Metro has big issues, which indicates higher demand – but more research would be needed to say for sure.

So if Metro delays keep happening, we should expect more wasted waiting time, more congestion, and more carbon emissions. We should not, however, expect more biking. That means we can’t rely on bikeshare alone to plug the holes in the transit system.

In your experience, do these results ring true? Do you jump on a bikeshare when the train is delayed?