This week was perhaps the most work-intensive of the quarter for the Friends of Caltrain group. Both Ma’ayan and Sam logged significant hours at the Stanford Geospatial Center working on the map renderings for our mode share and mode shift analyses. Following our check-in with Adina, the group reached out via email to Transportation Management Associations across the country that have successfully implemented TDM strategies. Ma’ayan and Sam hope to set up telephone interviews with the leaders of these associations to learn from their experience and develop a firsthand understanding of how TMAs go about achieving their goals.
During Patricia’s office hours on Wednesday, Ma’ayan and Sam finalized a step-by-step methodology for analyzing census data in tandem with the project specifications. Remarkably, the entire process can be summarized in four steps. These steps will be applied to 1990, 2000, and 2008 data:
1. Before using any of ArcGIS’s GeoAnalysis tools, we must finalize our list of Caltrain stations and project that data and our Census Block Group data into a flat projection. Because we are working with a relatively small geographic region, a flat projection will make it easy to construct our “buffer zones” of ¼, ½, 1, and 2 miles around each train station.
2. Using the Buffer tool, we will create circles of the above radii around each Caltrain station. Ultimately, these will the be the regions for which our analyses will be conducted.
*When constructing these buffers, we must decide whether or not to “double-count” the population that lay within the buffer zones of multiple Caltrain stations. Our decision on this matter will require Adina’s input and justification in our final paper.
3. Using the Intersect tool, we will use our buffer zones to pull data from the underlying block groups. Then, we will have to look at our data table for these intersections and perform calculations to approximate the commute-to-work mode share. Put simply, they will calculate a weighted percentage of each type of commuter, for each block group contained in the intersection.
4. With the Dissolve tool, we will finally combine the data fields that were calculated above into a single line of data for each intersection. This set of information will subsequently be analyzed to assess mode share shift between the three target years.
For the U.S. Census and ACS data that we compiled last week, we have already completed all of steps 1 and 2 and part of step 3. We have intersected the buffers with the block groups, but still need to perform our calculations before moving onto step 4.
During our meeting with Adina, we were asked to submit a comment on an EIR that is being finalized for a development project at the San Jose Diridon Caltrain station. On Thursday, Sam, using a half-mile buffer, completed the above steps for this station alone. She, Ma’ayan, and Adina hoped that the data would show a significant increase in Caltrain ridership for this region between 1990 and 2008. Unfortunately, minutes before the 5PM comment submission deadline, Sam came to the conclusion that the percentage of residents who commuted to work via public transportation for the half-mile region surrounding the Diridon station had actually shrunk by percentage points, from roughly 8.1% in 1990 to 7.8% in 2008. Because this result was not deemed valuable, no comment was submitted to the EIR.
Finally, we made headway this week in our TDM compilation by finalizing a list of 12 TMAs nationwide and contacting them all via email in hopes of setting up telephone interviews. In these interviews, we hope to learn from the successes and shortcomings of professionals working in the field. In advance of these meetings, we are finalizing a list of interview questions.
The TMAs that we have reached out to are: Arlington, Lloyd District, Boulder, Austin, Cambridge, Hacienda Business Park, Alliance (San Mateo), Contra Costa, TMASF, Mission Bay TMA, Emeryville, Moffet Park
So far, we have heard back from Austin, Hacienda, and Moffet Park.
What We Observed and Learned
There is a lot to take away from the progress that was made this week. Firstly, Ma’ayan and Sam are finally learning the ropes of ArcGIS. Though the software is agonizingly finicky and has a steep learning curve, repeated trial-and-error and meetings with Patricia have finally paid off. We are now comfortable enough with the interface and mechanics of the program to work individually on the maps.
Though Ma’ayan and Sam have not yet spoken in person after the results of Thursday’s Diridon study, both group partners are disappointed by the absence of a trend in mode shift for the station since 1990. Though one half-mile region does not speak for the entire Corridor, we might want to develop a plan-of-action in the event that our data does not exhibit significant trends over time. By this time next week, this issue will be resolved, one way or another.
Finally, our email correspondence with municipal TMAs has been hot-and-cold. While a representative from the Hacienda returned Sam’s email with a phone call and expressed excitement over our research, an employee from Austin’s TMA replied saying that, while we can set up an interview time “if we wish,” we might have better luck researching TMAs in California. These differing responses could foreshadow differing degrees of engagement we will encounter from these TMAs when we conduct our interviews.
Our work for next week is cut out for us:
1. Schedule and conduct telephone interviews with TMAs. For those who have not yet responded via email, we will conduct follow-up phone calls at some point during the week.
2. Complete the commuter analysis for residents along the Caltrain corridor. Ma’ayan and Sam have slated time on Tuesday afternoon to finish these three maps.
3. Collect data for employers along the corridor. Adina is putting us in contact with representatives from the MTC and SPUR who have conducted similar studies in the past. Hopefully, we will be able to tap into their data pool for our project.
4. Reach out to Jessica Zenk, the Senior Director for Transportation Policy in the Silicon Valley Leadership Group (SVLG). The SVLG is a community of the Bay Area’s largest employers, and we hope to speak to Jessica about some policies that companies are pursuing to encourage mode shift.