For MLK day here in the US, I'm going to be doing some equity #mapping work with #OpenStreetMap#OpenTripPlanner#QGIS and mabe some #Nodejs and posting some updates throughout the day in this thread. If that's your jam, follow along.
Otherwise, you may want to mute me for 24 hours, because this may get noisy. 🧵
🧵 So, I've successfully built a very small #OpenTripPlanner graph after using the #JOSM plugin to export a map. This is my "control" graph for current conditions. Later, I can modify the map in #JOSM, and build a "proposed" graph to generate isochrones for each. Context: https://urbanists.social/@markstos/111750037677375904 Thanks to @lehrenfried for taking a look at my OTP bug report.
🧵 I want to compare the 15 minute walk isochrones of a grocery store before and after a new planned connection is made to the sidewalk network. So first, I need to generate the isochrone "before". First, I need to decide how far to expect people will walk to a grocery. I'll use 15 minutes, in-line with the 15-min city principle, and also research that says that's about how far 90% of people will go for everyday purchases. https://blog.accessdevelopment.com/research-how-far-will-consumers-travel-to-make-routine-purchases
🧵 I immediately triggered a Null Pointer Exception in #OpenTripPlanner so that wasn't great. Maybe I can get some help in their Matrix channel. https://matrix.to/#/ In the meantime, I suspect it's related to a time zone not being set, so I may just find a way to set one.
I loaded a GTFS feed, but still triggered a crash in #OpenTripPlanner. I'll switch to trying #Valhalla for my isochrones. Time to read some docs first!
🧵 My first attempt at running the #Valhalla container. Ha, not off to a great start today.
terminate called after throwing an instance of 'std::system_error'
what(): Operation not permitted
/valhalla/scripts/configure_valhalla.sh: line 210: 36 Aborted (core dumped) valhalla_build_tiles -c ${CONFIG_FILE} -e build ${files}
🧵 I've got a working isochrone service with #Valhalla ! Now I can start making maps. The first map shows what I suspected, there's a neighborhood with a 15 walk of the grocery that has now no good connection to it.
🧵 Crossing the bypass on foot is one of the most dangerous intersections to cross in town. So this visualizes that about half the isochrone for the grocery is across the bypass and doesn't have a safe, comfortable walk there. #openstreetmap#valhalla#qgis
🧵 Turns out I had excluded the bypass when querying for roads to use to generate the isochrones, so I have to do re-do some work. As a reminder, I'm live-blogging as I go. Nothing in this thread is a finished product! I guess the good news is that ore people are within a 15 minute walk of this grocery?
🧵This map shows the effect of correcting my mistake. The extra area in red shows what the corrected isochrone will be. While not pleasant, those folks can also walk to the grocery with 15 minutes, as long they walk along the bypass to get there.
🧵 Ha, my map that excluded the bypass from consideration for walking may have been accidentally accurate. Turns out the state DOT doesn't even expect pedestrians to attempt to across Walnut along the Bypass. There is no cross walk, no pedestrian signal and the crossing is like what, over 100 feet across? #BloomingtonIN
I think is worse, is that 46 doesn't have any crosswalks OR sidewalks.
And also, Kinser Pike north only has 1 block of sidewalk, which starts at 46 and ends at Kroger turnoff. Which means people walking are relegated to walking on people's yards or on the road.
If the isochrone was redone to ignore no-sidewalk paths, Kroger would be an island.
@crankylinuxuser 🧵 This is a map of Bloomington that includes only trails, designated walk and bike facilities, sidewalks and residential streets, which are typically low traffic and low-volume. Now let's see who can walk to the northside Kroger in #BloomingtonIN using this map!
@crankylinuxuser To create that, I queried Overpass Turbo where "highway" was equal to cycleway, footway, trail, or residential, or where "sidewalk", was "both", "left" or "right".
@crankylinuxuser Here's a map comparing the 15-minute walk to the grocery from "legally allowed" locations (reddish) vs locations accessible by walking along a sidewalk, trail, bike facilities or residential road (greenish). Will I be comparing this contrast to at least one other Kroger location in town? You betcha. #Mapping#TranspoEquity#HealthEquity#OpenStreetMap#Valhalla#QGIS
One weird thing about the ped bridge in noth #BloomingtonIN is that it doesn't connect a sidewalk... on either side. On the south side it dumps you on a fast road on the north side it dumps you an in elementary school parking lot without even a crosswalk to it. There could be a straight line path from the bridge to the grocery, but no attempt is made. #TranspoEquity
Why build a ped bridge if it's not going to connect anywhere useful, or safely? "Pedestrian Bridges of North Texas" captures the vibe of how our government often uses pedestrian bridges to solve transportation problems. https://www.youtube.com/watch?v=mu5JqkufLtE
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