At Remix, there’s nothing we love more than seeing people use our software to help improve access through public transportation. That’s why we've been thrilled to have the opportunity to work with innovative academics like Madison Swayne, Marlon Boarnet, and Gary Painter at University of Southern California, who have been stretching the capabilities of Remix and inspiring the future of our product development. In a recent study, Swayne’s team used Jane—a Remix feature that maps distances by travel time, and is named after Jane Jacobs, the famous journalist and urbanist from the 1950s and 60s—to identify how various changes to the Los Angeles transportation system would affect residents’ access to jobs.
Swayne’s research team is part of the Sol Price School of Public Policy at USC. For this particular study, the team looked at how potential changes to public transportation would impact transit accessibility and travel time to job sites. The potential changes in question were from the 40 transit projects that Los Angeles County Metropolitan Transportation Authority (LA Metro) identified as projects they’d like to carry out over the next 40 years. Understanding exactly how these changes to the transit system will affect job accessibility is critical for the agency as they prioritize their future plans. To do this, they need accurate data and projections. That’s where USC comes in.
The USC research team selected three of the 40 potential future transit projects outlined by Metro to focus on for this study: two Metro Rail line extensions and the creation of a new bus rapid transit line. Then, they analyzed each project to learn how it would affect job accessibility. With the information gleaned from this study, Metro can make the most impactful changes to their transit system and make sure they’re funding projects that provide the greatest value to local residents.
Once USC researchers identified which potential transit projects they wanted to analyze, they used Remix and Jane to calculate job accessibility for each project option. More specifically, they looked at how many potential jobs a person could access from various locations, within various commute times.
First, the researchers modeled L.A. County's existing transit network using Remix. To do this, they used open-source General Transit Feed Specification (GTFS) data, which allows researchers to easily input stops, routes, trips, and schedules associated with the transit system. Then, they augmented LA Metro’s GTFS data to include the three planned transportation improvements.
Next, the researchers needed to identify locations that would function as the starting points of residents’ transit trips—in other words, their homes. Researchers identified the center point of each of L.A. County’s more than 2,000 census tracts to represent the starting point for people who live within the tract. This method allowed researchers to calculate an average travel time and distance to work locations for everyone living in the census tract.
Finally, the researchers calculated how many jobs were accessible from each census tract, depending on how much time residents would spend commuting. Specifically, they looked at job access via public transit and excluded other possible modes.
With their starting points identified, the team then turned to Jane to find the total number of jobs people could access from that point via transit within a specific timeframe. For each tract, they used Jane to calculate how many jobs were accessible for commutes of 15, 30, 45, and 60 minutes.
Jane is an isochrone tool, or a tool that allows users to calculate and map distance according to travel time.
Without Jane or a similar isochrone tool, researchers would have to use static methods when measuring access instead. Static measures involve drawing a straight line or using another approximation, while Jane returns precise distances determined by the transit network and travel times. Jane provides more flexibility to the older methods.
The USC researchers noted in their paper that most transit research studies aren’t based on travel time because of "the large workload required to gather network data, route trips over a network, and calculate access measures." With Jane, however, researchers can worry less about the tedium of data-gathering and more about getting the results they need to benefit residents of their cities.
The work that USC is doing is the essence of what we at Remix hope to accomplish with our products and services, and we applaud the USC research team for their creative use of technology. Since this research, Remix has made improvements in Jane, increasing her ability to measure access to jobs, service, and households. Dr. Swayne and researchers like her inspire us to continue making improvements to Remix’s accessibility features. Stay tuned for more to come in a few months.
If you want to learn more about Jane, go to remix.com/demo.
Read Capital Metro's story on leveraging a collaborative approach to transit data to implement transit prioritization.
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