I’ve been trying to get this post done for a while, but RailVolution and working on the Transit Appliance have kept me a bit busy.

I’ve also been musing over a couple of very interesting posts from Jarrett Walker at Human Transit that talk about the interaction between transit and density and the difference between average density and clusters of density (“the perils of average density” and “can we make density make sense?“).

This thought process just confirms to me the need to move our analysis down to the Block Group level. So that’s priority # 1.

I’m also very interested in finding a way to visualize the affect on transit score of MAX lines, frequent service lines and local service. I think that’s a great heatmap application, but I think the data need to be more fine-grained than the point spacing I used to score census tracts, so I’ll probably generate a new data set – one that also doesn’t worry about boundaries of census tracts, but stays closer to a true grid. I’m thinking about using the Hollywood district as the example for this, but I’m open to suggestions about other areas that might have all three types of service to serve as examples.

Meanwhile, I did manage to compile one other data set, which is a set of transit scores for all the transit stops in the TriMet system (it’s the GTFS stop file enhanced with the three result fields from Transit Score). If someone has the time or interest to do a visualization, I suspect that would be very interesting.

Finally I’ve been thinking about other “physical” data sets that I’d be interested in correlating with Transit Score:

• Distance to the “center” of the transit system
• Distance to a Regional Center
• Distance to the nearest High Capacity Transit stop (MAX, WES)
• Intersection Density

The first three can be calculated from data I already have, I’m hoping I may be able to get the intersection data as a by-product of work already being done on the Portland Plan by the Bureau of Planning and Sustainability. If so, I’ll encourage them to add it to the Civic Apps open data sets.

So please be patient, I suspect it will be a number of weeks before I can assemble enough time to get the Block Group data set done…