Smarter Statistics

Blog Post created by KHuber-Wilker-esristaff Employee on Sep 23, 2018

Transit ridership numbers have always been difficult to measure. Sure agencies can often provide gross numbers by week or month, but does that really tell the whole story? You have to look deeper into the numbers to understand the context in which ridership increases or decreases. Let's take WMATA or the Washington Metropolitan Area Transit Administration. In 2016 amid budget shortfalls, deferred maintenance, and a string of high profile incidents, WMATA decided to cut back service. This meant that trains would now only come every 8 minuets during peak periods, and every 10-15 minuets during off-peak periods. To make matters worse, complete shutdowns of track sections for extended periods of time during "Safe Track" meant that some customers had no service, or would only see trains every 24-30 minuets, even during peak periods. Naturally ridership has plummeted, as less trains = less space for people to ride, and service disruptions combined with the rise in ride share popularity means that people no longer depend on Metro to move around DC.


So after all of this, one would naturally expect ridership to have continued to plummet to the present day, and while that may be true, pure ridership numbers don't fully tell the story of WMATA's contribution to DC's transportation network. Let's take Crystal City station's ridership numbers into consideration. Between 2007 and 2012 Crystal City averaged over 14,000 boradings a day. In 2014 it had 11,959 riders per day (RPD), while in 2016 it had 11,480 RPD, in 2017 it had 10,252 RPD, and in 2018 it has had 10,501 RPD. The stations around it including Pentagon City, Pentagon, and Braddock Road have also seen similar drops, suggesting that the drop in ridership along the Blue/Yellow line in Virginia is not unique to any specific area. But what about ridership in relation to trains per hour, total service hours, and number of fully operational days?


Before the Silver Line opened in 2014 and before WMATA had to perform emergency maintenance over the past 4 years, the tracks handling the Orange/Blue Lines together was able to handle up to 30 trains per hour (TPH) with 20 being Orange and 10 Blue. However, this was theorized to operate with Automatic Train Control (ATO), and running shorter 4-6 car trains. Usually in practice it was closer to 14 Organge and 14 Blue Trains per hour over the same lines. Today, the Orange, Blue, and Silver Lines each see about 8.67 TPH during the 9.5 Hours of peak operation, and 5 TPH on non-peak hours and the weekend. Non-peak hours account for 10 hours M-Th, 11.5 hours on Friday, 18 hours on Saturday, and 15 hours on Sunday. Normalized by (PTPH/TPO*OPTPH/TOPO)/TDA*100 you can understand what ridership actually should be based off of historical standards and given the current service levels M-Th. Here we see that the current daily weekday boardings for Crystal City should actually be 10,882.69 M-Th and 12,606.78, as opposed to the 10,501 RPD that we currently see. What could contribute to the difference between the projected numbers based off of historical levels, vs. the current numbers? Well for one, it is difficult to account for the rise of teleworking, ridesharing, and bikeshares. However, with these numbers holding true throughout Arlington and Alexandria, given current service levels, these areas along the Blue and Yellow line should be primed to experience growth soon. Next we will look at visualizing these numbers as well as digging a little deeper into their analytics.