Behind the scenes with MBTA data.

The Federal Transit Administration (FTA) Title VI Circular (C 4702.1B) requires large transit providers to collect demographic, travel, and fare payment data about their riders using passenger surveys at least every five years. The MBTA, working with the Central Transportation Planning Staff, has just completed a systemwide passenger survey to collect necessary passenger demographic data for bus routes and rail stations. This project updates the 2008-2009 dataset and will be used for service planning, ridership analysis, and Title VI equity analyses.   

The MBTA knows this data is useful for many other research projects, so we are releasing an interactive tool that allows you to compare the results for stations and bus routes. You can also download the associated datasets. 

Screenshot from the Rider Census online tool

Survey Methodology

The survey responses were obtained through a combination of an online form that was available from late October 2015 to May 2017 and a paper form with mail-in option, distributed at MBTA stations and on board MBTA vehicles from March 2016 to March 2017. Approximately half of all completed forms were submitted by each method. The English version is shown below.

The survey plan called for obtaining responses at the route level for bus and ferry routes and at the station or line segment level for all other modes. A goal was to obtain at minimum enough responses from each route, station, or line segment to meet statistical requirements for a confidence level of 90 percent with a confidence interval of 10 percent. In cases where the number of responses was insufficient to meet these standards, results from two or more routes, stations, or segments serving the same general area were combined. 

To compensate for differences in response rates when comparing results from different lines or modes, the published results for each route, station, or segment are weighted in proportion to typical weekday total passenger boardings on the corresponding services based on recent count data. 

More detailed methodology can be found in the survey report, available soon.

Data Considerations

Please consider the following in working with these data:

90/10 confidence and precision: Below the 90/10 level, data are not displayed (the tool shows “Insufficient Data”). The displayed routes and stations all meet at least this level of confidence and precision, but some services are near this threshold, and some are much more precise. The additional precision mostly comes from higher samples on high ridership routes and stations. In addition, we assumed the “worst case” of evenly split characteristics in order to evaluate the confidence and precision levels. Since some characteristics are not expected to be split evenly among riders, even data included at the 90/10 levels is likely to actually be more reliable than 90/10.  

However, because the confidence and precision levels can vary, it is important to take into account the possibly-wide interval range when comparing routes or stations to each other. Conclusions about differences among services are likely to be more reliable for higher-ridership routes and stations, or at aggregations of services (e.g. at the mode-level). In order to assist with this evaluation, the valid sample counts for each question are provided along with the weighted response data in the downloadable datasets. 

Check all that apply: Questions that allowed respondents to check multiple responses will have answer options that total more than 100 percent. These questions are:

  • Do you sometimes make this trip another way? and
  • How do you self-identify by race?

Trip-specific information: Some questions have wording that is trip-specific and cannot be generalized to MBTA use overall, including:

  • “Fare payment” applies to the reported trip, not to fare payments overall
  • “Trip frequency” applies to the reported trip, not to the frequency of riding the MBTA
  • “Alternative modes” refers to alternative modes for the reported trip, not for alternative modes to the MBTA in general 

Survey response bias: Some groups of people are more likely to respond to surveys than others. Disparities in results for these groups suggest a disparity in the response rates between the groups rather than such a large difference in the actual ridership population. Specifically, the gender disparities and English-speaking ability disparities are likely effects of response bias (women and English-speakers are more likely to respond to surveys) and not necessarily representative of the population. For these demographic elements, the reported values are likely to be biased, but the trends are likely reliable (i.e. a bus route with more women than another bus route likely does have more women, but the percentage of women on both bus routes is likely over-estimated). 

Additionally, we believe that visitors to the region and the MBTA are less likely to fill out and return surveys than regular riders. This response bias reveals itself most in the fare payment data – the portion of survey respondents who reported using monthly or seven-day passes is higher than the portion recorded by our fare system paying with these passes. This and other biases may show up in other results as well.

English Proficiency: The “Ability to Understand English” results cannot be assumed to provide an accurate measure of the percent of MBTA riders with little or no English proficiency because 99 percent of the returned survey forms used the English version, and forms were available in a limited number of other languages (Spanish, Portuguese, Cape Verde Creole, traditional and simplified Chinese, Vietnamese, French).