I said when I was working on the bike map that I would get around to publishing the ‘source code’, and now that I’m preparing to leave the city, I feel I ought to finally do that. So! The basic idea of this post will be a step by step instruction for how to make yourself (or your city) an updated Cincinnati Bike Map. Strictly speaking, this will work for other cities too, but please note that the map was designed for Cincinnati in 2014 and other cities in other times, with different (data) structures may simply not work well at all.
Let’s get started!
Step 1: Get the software you’ll need: QGIS, PostGIS(a PostgreSQL extension), osm2pgsql, osm2po, GRASS, PHP(for one of the scripts), and Inkscape and GIMP for the final layout. All are free and open source and run on Linux (but probably other things too).
Step 2: Update the data! A big and important step. The vector data is all from OpenStreetMap and the process of editing OSM is well documented elsewhere, so I needn’t go into it at all here.
Step 3: Go to OpenStreetMap and navigate to the area you want to download. Be generous and include at least ten extra miles on all sides of the map you’ll be making. Click the ‘export’ tab and use the ‘Overpass API’. It will prompt you to download a large .osm XML file to your computer.
Step 4: Import that data into a PostGIS database twice: once with osm2pgsql and once with osm2po. The first will bring in the OSM data as-is, with as many tags as you care to import. To do it the way I did it, you should use this osm2pgsql.style file. The second one, osm2po will slice the linear path data (the streets and stuff) into a table of routable nodes and edges. For that one, you may want to try this configuration file. If that doesn’t work, the real point of it is to include paths that bikes can use (paths, pedestrian streets, stairs, etc), which are not included by default, while leaving out the rest.
Step 5: Process the data from osm2pgsql using this SQL script. It does quite a few things, including setting (short) street labels, calculating speed in mph, setting default speeds and lane-counts for no-data streets, identifying landmark buildings, and pulling a number of features into a consistent format for better/easier rendering.
Step 6: Run this SQL script to merge the two tables you’ve imported into one table that is both routable and has all of the important attributes/tags from OSM.
Step 7: Run tarjan.php on the new/duplicate segments table. This script uses Tarjan’s Algorithm to identify edges that connected at both ends to the main street network, and those that are not, leaving the results in a boolean field on that table.
Step 8: Once the dangling edges are identified, run this SQL script to drop the minor paths that go nowhere. Major dead-ending streets will be kept. Things like driveways will be dropped.
Step 9: Get the elevation data. I used data from the USGS (use their national map tool to download). I found that of the two decent resolutions available, one was too course (I could see pixels) and the other was too fine (I could see buildings). I chose to smooth out the finer data, using a neighborhood average in GRASS. I suppose you could also go at that the other way though too, increasing the resolution and then smoothing. The point is to get an amount of detail that just looks right and doesn’t have any visible pixelation: use your gut!
Step 10: Now you have all the data ready to go in your PostGIS database, and you just need to drop it into QGIS and style it. I wish things were easy enough that I could share a simple stylesheet with you; the way QGIS does it, the style information is all bound up with information about the table. That means that if your table/database/column/everything names are different from the ones I used, you’re going to have trouble making this run smoothly. In the interest of giving something here though instead of nothing, I’ll link to the QGIS map files used to render the main and inset maps (hills, transit, and trails). These may not be directly useful, but you could look at them as XML files, and see precisely how things were styled including line widths, hex colors, etc. It may also be useful to sample colors directly from the digital version of the map using something like GIMP. Once ready, export these maps as 300+DPI rasters using the following templates: main map, 1/3 scale inset maps.
Step 11: Now we have the base maps, we’re finally ready for the layout! I did the layout in Inkscape SVG, linking to the exported raster maps which I placed in an adjacent directory. You’ll have to re-link those, but the frames should still be in the right position.
Step 12: Profit.
Well, that’s about the gist of it. … I don’t actually think that hardly covers it, but there’s not enough time in the world to document everything for an uncertain future that may or may well not contain good bike maps. And anyway, I don’t expect anyone to slavishly duplicate my approach. We’ll call it a limited edition ;-)
If someone does actually want a real update though, I’m always available to answer questions, or if you’re the type to cut right to the chase, for hire. Email me!
UPDATE #2: Fundraising is done!
UPDATE: Sponsors so far include the Haile Foundation, Steve Magas, the UC Geography Department, UrbanCincy, Frank Henson, REI Cincinnati, Urban Sites, James Braye, Jack & Lyn Martin, and Gaslight.
The Cincinnati Bike Map, now so nearly complete, seeks sponsors to help finish the work and get the project to print.
Here’s the basic idea: Most bicyclists, most of the time, are using the streets. They’re using the streets for increasingly diverse ends in fact, from training for a race to picking up groceries. Such diverse users, each with their own ends and abilities, must have objective information on the conditions of the roadway, most notably of their potential relation to it’s automotive traffic, if they are to make informed decisions when planning their trips or finding their way.
Beyond this navigational goal, the map is also an advocacy tool, showing objectively what someone might expect were they to try riding a bike. This role emphasizes the importance of a tangible, printed map, as opposed to a shifting, digital one, in conveying a reliable, secure reality that people can learn to understand and depend on; a security they must feel if they are to try something they are unused to.
Concretely, the map will measure 24″x31″, fold down to a pocket-size 4″x5.16″, and take in 210 square miles of Cincinnati and Northern Kentucky at a 1:28,000 scale. 10,000 copies will be printed locally and distributed for free through a variety of outlets targeting cyclists and potential cyclists. All data and work will be available, freely under an open license.
Your sponsorship supports this work and gets your name on the map.
- Individual: $50 — get a thank-you shout-out on the map, and as many copies as you can use/distribute mailed to your home address.
- Silver Level: $200 — The above and your organization’s logo on the map.
- Gold Level: $500 — The above and two lines of text next to your logo such as a url, address or coordinate location on the map
If you’re interested in sponsoring, please send me an email with your information. You can and use the button below to donate through paypal or I can give you an address to send a check.
I’m shooting for publication in Late July or Early August.
Thanks to a very generous grant from the Haile Foundation, we’re most of the way to our goal of $7,000 for production and printing.
Raised already: $6,800
Left to go: $200 )
What the money will be used for:
About 80% of the money will go directly to printing and distribution costs. The rest will help me keep a roof over my head while I finish the project since I have no real income over the summer. That’s right, about $1,400 to pay a highly educated cartographer for a couple month’s hard work. I live pretty cheap ;-)
What still needs done:
- There are a few places I know I need to ground-truth the OpenStreetMap data and make updates and corrections, notably the West Side and parts of NKY. I’m sure this involves at least three days on a bike, riding around checking speed limits, verifying the existence of water fountains and traffic lights, one-way streets and various other things.
- I need to finish thinking through the necessary contents of a couple inset maps, pull those together and fit them into the layout.
- Several over-all stylistic choices need to be made still, including the final colour-contours for the elevation layer which still aren’t totally satisfying.
- Once the data and layout are completely finalized, the map needs detailed annotation and careful labelling of the more detailed features.
- Then finally, distribution, which I expect will take a couple weeks on and off.
I thank you heartily and preemptively for your support.
It is the implied authority of geospatially precise ‘bike route recommendations’ that puts me off; my travelling ontology doesn’t recognize such routes.
Bike routes to me, where not literally demarcated by bollards or boundary paint, are a loose, conceptual topology of best-paths contingent on weather, health and my day’s ambition. There are rare edges that are fairly static and these can be mapped: Spring Grove can be for racers and relaxation, snowing or scorched. But why transpose it literally? “Spring Grove”, as I mean it, is a heuristic referencing the whole street, perhaps even to the whole Mill Creek valley east of the tracks, not a geocoded centerline. Ol’ Colerain sliced by the highway is a good ride too, and I take it sometimes if I feel like looking at something different.
How to communicate such useful, abstract edges?
A hand-rendered, schematic map is so clearly subjective it openly invites criticism from the viewer’s own ideosyncratic subjectivity. This is ideal. The point of bike-route maps cannot be to convey authority but to connote personal suggestion.
Here is my morning’s attempt at a bicycle edges map, from memory and a half-hour.
Now to digitize and make it look decent…
What’s all this about a West//East divide? I’d like to propose a distinct Car-Free-Cincinnatian spatial identity that apparently fails to recognize any but the central neighborhoods and places well-connected by transit. I couldn’t for the life of me recall how to bike to Xavier, NKU, or College Hill because I so often take transit to those places. My concept of the city seems to have a very tightly connected core with more distant neighborhoods dangling from abstract transit lines but no street names. This may more accurately be my winter version of the city. Come summer I’m much more likely to bike laterally.