Page 132 of 170

Obtaining Chicago Transit Authority geodata

October 12, 2010 / / 0 Comments

A reader asked where they could get Chicago Transit Authority (CTA) data I didn’t already have on the “Find GIS data” page. I only had shapefiles for train lines and stations. Now I’ve got bus routes and stops.

You can download General Transit Feed Specification (GTFS) data from the CTA’s Developer Center. It’s updated regularly when service changes.

Screenshot from ESRI ArcMap showing the unedited shapes.txt file loaded via Tools>Add XY Data. Shapes.txt is an 18 MB comma-delimited text file with thousands of points that can be grouped together with their shape_id.

The GTFS has major benefits over providing shapefiles to the public.

  1. It can be easily converted to the common shapefile format, or KML format.
  2. Google, the inventor of GTFS, has defined and documented it well; it is unencoded and plaintext. These attributes make it easy for programmers and hackers to manipulate it in many ways. (see also item 4)
  3. Google provides a service to the public on its website, an easy to use and robust transit planning service.
  4. The data is stored as plaintext CSV files.
  5. While an agency like CTA may have a geodata server on its intranet, it is less likely it has the addons that provide mapping and geodata services for the internet. A server like Web Mapping Service, or ArcIMS. These systems can be expensive to purchase and license. And we all know how the CTA seems to always be in a money crunch. While the CTA updates its GTFS data for publishing to Google Maps, the public can download it simultaneously to always have up-to-date information, providing the same geodata that ArcIMS or WMS would offer but for no additional cost.

I couldn’t have pulled off this conversion in 24 hours without the help of Steven Romalewski’s blog, Spatiality. He pointed me to the right ArcMap plugin in this post about converting the Metropolitan Transportation Authority’s GTFS data into shapefiles. I hope Steven doesn’t move to Chicago less my authority on GIS and transit be placed in check!

Make your own map of the CTA train routes and perform some kind of analysis – then share it with the rest of us!

Read more about my exercise in geodata conversion in the full post.
Continue reading

How to convert GTFS to GIS shapefiles and KML

October 12, 2010 / / 41 Comments

This tutorial will teach how you to convert any transit agency’s General Transit Feed Specification (GTFS) data into ESRI ArcGIS-compatible shapefiles (.shp), KML, or XML. This is simple to do because GTFS data is essentially a collection of CSV (comma separated values) text files (really, really large text files).

Note: I don’t know how to do the reverse, converting shapefiles or other geodata into GTFS data. I’m not sure if this is possible and I’m still investigating it. If you have tips, let me know.

Converting GTFS to GIS shapefiles

Instructions require the use of ArcGIS (Windows only) and a free plugin called ET GeoWizards GIS for any version of ArcGIS. I do not have instructions for Mac users at this time.

I wrote these instructions while converting the Chicago Transit Authority’s GTFS files into shapefiles based on a reader’s request. “Field names” are quoted and layer names are italicized.

  1. Download the GTFS data you want. Find data from agencies around the world (although not many from Europe) on GTFS Data Exchange.
  2. Import into ArcGIS the shapes.txt file using Tools>Add XY Data. Specify Y=lat and X=lon
  3. Using ET GeoWizards GIS tools, in the Convert tab, convert the points shapefile to polyline.
  4. Select the shapes layer in the wizard, then create a destination file. Click Next.
  5. Select the “shape_id” field
  6. Click the checkbox next to Order and select the field “shape_pt_sequence” and click Finish.
  7. Depending on the number of records (the CTA has 466,000 shapes), it may take a while.
  8. The new shapefile will be added to your Table of Contents and appear in your map.
  9. Import the trips.txt and routes.txt files. Inspect them for any NULL values in the “route_id” field. You will be using this field to join the routes and trips table. It may be a case that ArcGIS imported them incorrectly; the text files will show the correct data. If NULL values appear, follow steps 10 and 11 and continue. If not, follow steps 10 and 12 and continue. This happens because ArcGIS inspected some of the data and determined they were integers and ignored text. However, this is not the case.
  10. Export the text files as DBF files so that ArcGIS operates on them better. Then remove the text files from the Table of Contents.
  11. (Only if NULL values appear) Go into editing mode and fix the NULL values you noticed in step 9. You may have to make a new column with a more forgiving data type (string) and then copy the “route_id” column into the new column. Then continue to step 12.
  12. Join routes and trips based on the field “route_id” – export as trips_routes.dbf
  13. Add a new column to shapes.shp called “shape_id2”, with data type double 18, 11. This is so we can perform step 14. Use the field calculator to copy the values from “shape_id” (also known as ET_ID) to “shape_id2”
  14. Join routes_trips with shapes into routes_poly based on the field “shape_id” (and “shape_id2”)
  15. Dissolve routes_poly on “route_id.” Make sure all selections are cleared. Use statistics/summary fields: “route_long,” “route_url.” Save as routes_diss.shp
  16. Inspect the new shapefile to ensure it was created correctly. You may notice that some bus routes don’t have names. Since these routes are well documented on the CTA website, I’m not going to fill in their names.

Click on the screenshot to see various steps in the tutorials.

Converting GTFS to KML

After you have it in shapefile form, converting to KML is easy – follow these instructions for using QGIS. Or if you want to skip the shapefile-creation process (quite involved!), you can use KMLWriter, a Python script. Also, I think the latest version of ArcGIS has built-in KML exporting.

Converting GTFS to XML

If you want to convert the GTFS data (which are essentially comma-separated value – CSV – files) to XML, that’s easier and you can avoid using GIS programs.

  • First try Mr. Data Converter (very user friendly).
  • If that doesn’t work, try this website form on Creativyst. I tested it by converting the CTA’s smallest GTFS table, frequencies.txt, and it worked properly. However, it has a data size limit. (User friendly.)
  • Next try csv2xml, a command line tool. (Not user friendly.)
  • You can also use Microsoft Excel, but read these tips and caveats first. (I haven’t found a Microsoft application I like or think is user friendly.)

Verifying LEED certification and eco-friendly features

October 11, 2010 / / 0 Comments

Read more commentary on LEED certification.

If a building claims it has environmentally friendly features (is that the same as eco-friendly?) but hasn’t applied for and received LEED certification, should we still call it “green”?

I’m talking specifically about Emerald, a two-tower (mid-height) condominium development on Green Street in Chicago’s Greektown/West Loop neighborhood. I watched its construction from beginning to end because I passed it daily on my commute to work.

The development’s sales website claims that because it sits on Green Street, it’s “naturally eco-friendly.” The website says the building has “bamboo flooring, low-VOC paint and beautiful fabrics made from recycled fiber. Even our marketing materials utilize recycled paper manufactured with windpower and printed with soy inks.”

These scaffold panels are advertising office space in a new tower that has since been built on this site. The one on the right reads “Reflect the social conscience of your organization.” Photo by Payton Chung.

Additionally, it has a 4-pipe HVAC system versus an “inferior” 2-pipe system, and high efficiency windows.

But I looked in the U.S. Green Building Council’s (USGBC) Certified Project Directory and didn’t find a project named “Emerald.” Let’s assume my search and the results are correct and Emerald does NOT have LEED certification. Are the claims on the website accurate? How can we trust that the paint truly has less volatile organic compounds?

If it was LEED certified would we trust it more then?

The building advertised in the photo above, 300 N LaSalle, received two certifications: Silver in Commercial Interior, and Gold in Core & Shell. The advertisement’s claims have some verification, but how trustworthy? My photo.

I’m not a LEED AP (Accredited Professional), but I understand that LEED certification requires thorough documentation. After a review of your application and submittals (essentially an audit), the USGBC makes its determination. I don’t believe anyone representing the USGBC inspects the building.

We then have to question why the Emerald developers didn’t seek LEED certification. Or did they?

What do you want to know

October 9, 2010 / / 0 Comments

Open thread.

What information about urban planning would you like to know?

Or do you want to know something more about me?

I’ve made it really easy to leave comments in this blog and I hope you’ll leave one on this post asking me a question or requesting that I write about a specific topic.

Maybe you want to know how curb cuts are made.

Or if it really takes flashy fixtures and construction to become or be known as sustainable.

Are you curious about bike lane design?

Park wins while parking fails neighborhood

October 8, 2010 / / 0 Comments

This post on the removal of car parking at a park inspired me to write this post about the addition of car parking at a park.

Palmisano (Stearns Quarry) Park was created out of a dolomite limestone quarry and landfill in Bridgeport. The park is well designed and has a variety of landscape features. It’s quite popular, especially with elderly Asian residents.

Now, after a year of it being open, many diagonal parking spaces were installed on 27th Street. Space was removed from the parkway to create additional parking spaces where only parallel spaces existed.

Access to the park is not an issue. There are hundreds of households and thousands of residents within half a mile. There’re bike lanes and bus stops. There is a signalized intersection that makes it safer for people to cross the street to the park. Lastly, there are many unused parallel parking spaces lining two sides of the park.

So why was parking added? Did the neighbors ask for it? Did the Chicago Park District feel new parking was needed?

In a nutshell, my complaints against this are:

  1. It removed parkway – this should be sacred space. Perhaps we can institute a “tit-for-tat” policy (modeled after a parking meter agreement*) where if parkway is removed in one place, parkway has to be expanded or improved in another place.
  2. Potentially increases traffic in area by encouraging more driving by offering free parking. All parking surrounding the park is free.
  3. Parking space for drivers with handicap badges does not have a ramp. This is the most perplexing part – you may have to open the photo to its full size to notice this.
  4. Bumpout is not a bioswale. I highly doubt anyone will maintain the grass and soil. This landscaping will die.
  5. Bumpout’s large radius will not calm traffic (I watch it every day).

I would like to see the bumpout “island” transformed into a proper curb extension at a stop sign where drivers typically pause in the crosswalk and quickly turn right into southbound Halsted without stopping. I would like to see a bioswale collect the water from the street at this curb and divert it to the park’s wetlands.

*As I understand it, if parking meter spaces are removed and converted to another use (like a curb extension or on-street bicycle parking), a non-metered space must be converted to the equivalent metered spaces removed.