Our motivation for this project was to better understand Portlanders transit preferences in relation to different types of weather. Specifically we wanted to look at how high levels of precipitation impacted TriMet transit system ridership in relation to rideshare users. Our hypothesis was that we would see a slight decline in TriMet bus ridership and a corresponding increase in the number of rideshare users. Unfortunately, the City of Portland does not require rideshare companies to publicly disclose any of their internal data, so we were not able to include rideshare user data as a part of our project.
Instead, through a multiangle analysis of the Trimet transit system we explored if and how precipitation impacts ridership within the MAX, WES, and Bus systems on a month-to-month and year-to-year basis, as well as a brief exploration of the cost per boarding passenger to identify strengths and weaknesses throughout the TriMet transit system. Additionally, we created two transit system maps designed to enable users to explore the geography of the TriMet transit system and how ridership varies from neighborhood-to-neighborhood and city-to-city.
See Data Sources for more information
There are multiple views combining the total monthly precipitation data (across 6 cities in the TriMet service area) with the estimated total monthly ridership on TriMet (taken from a weekly average for each month):
All charts are used to explore the relationship precipitation has with ridership. While there seems to be no obvious patterns with regards to precipitation's impact on TriMet’s ridership at a monthly level, it is important to note that other variables (such as seasonality, weekday vs. weekend ridership, year over year decline in overall usage, etc.) were not and in some cases could not be factored into the included charts.
The Cost vs Rides chart shows the cost per boarding passenger for buses in each of the four sample periods between 2018 and 2019. The worst and best performers were identified, and maps were used to find where these routes run.
Overall, it appears that bus ridership was less likely to be impacted by precipitation when compared to the WES and MAX which show a slight decline in riders in months with heavy precipitation. There is also a clear seasonality that presented itself when looking at the month over month ridership for each year. The summer months (June through August) show a dip each of the three years as does the month of December. This could be due to multiple factors (riders more likely to bike or walk in nicer weather, students no longer taking transportation to school, workers and students taking vacations, etc.). 2019 is the year with the heaviest overall precipitation and the lowest performing year for TriMet, but this may be less to do with weather and more to do to the general decline of in ridership that TriMet has experienced over the last several years.
Charts and maps show that the WES is the least used part of the system. The highest cost is Route 97 running between Sherwood and the Tualatin WES station. The conclusion is that buses feeding into the WES will not be cost effective due to the low usage of the WES. The most cost effective is Route 14 running from downtown Portland to I205 and Foster. Its high density of bus stops in a fully populated area make it the route that is closest to being profitable.