Underground Mapping

Ever wonder what’s beneath the roads in Chicago?

Chicago–founded in 1837–has a maze of water pipes, cables, and tunnels that have accumulated over the city’s 180 year history. There are communication lines, both old and new, that crisscross the streets. Every day in the city, construction crews conduct something akin to open heart surgery each day to upgrade water main lines, repair gas lines, and even lay new fiber optic cable while removing telegraph wires. Of course, this is not unique to Chicago. In the United States, over 400,000 underground excavations take place each day. Since some of this information is outdated or not easily accessible, there is an excavation incident roughly every 60 seconds and causing an estimated $1.7 billion in costs.

The City of Chicago has teamed-up with UI Labs’ City Digital to launch a pilot with a that will begin to deploy a platform to collect and create a 3-D map of underground infrastructure. This platform will provide a clearer insight so engineers and crews can better plan their work, identify issues, and lower the overall time to complete underground excavations and reduce costs. By housing this information in a platform, it will allow the City of Chicago to securely share limited data with utilities and other organizations that need to understand what is below Chicago’s roads, while limiting to only sections that are needed to be known.

Rendering of subsurface infrastructure

Rendering of subsurface infrastructure by HBK Engineering

Digital maps do already exist of Chicago’s subsurface labyrinth. But these often represent construction plans. Sometimes crews go beneath the street only to find there is a need to improvise, often because they come across undocumented structures that impede their initial plans. This new approach will use basic digital cameras and sophisticated software to scan the actual underground assets in the city.

Photo of underground infrastructureA project like this cannot be done alone. City of Chicago teamed up with UI Labs’ City Digital and their partners, HBK Engineering and Accenture, to kick-start this project.

New technology developed by University of Illinois at Urbana-Champaign’s Real-Time and Automated Monitoring and Control Lab (RAAMAC) and Chicago start-up CityZenith will allow the city to scan and 3-D map Chicago’s underground assets.

One difficult part of a project like this is collecting the correct data that is economical and relies on widely available techniques. RAAMAC’s solution allows images captured from off-the-shelf cameras, such a basic DSLR camera.

Those images are inputted into RAAMAC’s software to create a stereoscopic image that renders a computer model of the underground infrastructure. Over a dozen images can be seemlessly captured during typical repair and construction adding no additional time for data collection. On-site engineers are able to collect this information without interfering with crews and with cameras that are affordable.

Underground utility stereoscopic map derived from DSLR pictures

Underground utility stereoscopic map derived from pictures using standard digital cameras

These renderings can be provided to engineers, planners, and crews. These models can also be securely shared between the City of Chicago and other companies with underground infrastructure to improve project planning and limiting accidents. Sharing can be limited to specific areas in the city so information does not get over-shared. For those with access, they will be able to see detailed renderings of the location of the underground infrastructure with rich metadata on each pipe, fiber optic connection, water main, and more:

The visualization will provide more than just a sophisticated interface. Having a full understanding of the city’s underground infrastructure will help avoid accidents that have a history of interrupting commutes or worse.

The first Array of Things sensor went online on September 1st and since then, 3 more sensors have gone online. Array of Things was deployed with a commitment to transparency and today we’ve launched an interactive map of the installed and planned sensors to be installed on Chicago’s Open Data Portal.

You can download the raw data behind the map from the portal as well.

Array of Things will continue to expand throughout the next couple of years for a total of 500 sensors. Later this year, after the data from the sensors are validated, data will be streamed online and in the open so researchers, citizen scientists, and the curious can analyze the data.

Fall is around the corner and so is school. Now there is a lot extra on the data portal for those who are interested in school data. Chicago Public Schools has posted 10 years of maps on the City of Chicago Open Data Portal, ranging from school locations, attendance boundaries, safe passage routes, Charter school “preference” and geographic network boundaries, and Local School Council (LSC) Voting Districts.

Each one of these data sets can be interactively viewed on the data portal or downloaded to make your own custom maps. The following datasets (50 altogether) are currently available on the City’s Open Data Portal:

These data compliment dozens of education data sets already on the Open Data Portal, including the location of Chicago Early Learning programs and annual progress report cards.

Details for the data nerds

There is a special treat for school data enthusiasts who want to combine and merge all of these data. Attribute table field names and data types (including test field lengths) will remain consistent for all attendance boundary and school location shapefiles. This means, for instance, that you can easily match schools listed in the Local School Council (LSC) with data in the School Locations, reducing the time and effort of trying to match school names.

There will be some exceptions. Prior to school year 2007-08, a 4-digit “UNIT_ID” format was used. For 2007-08 and on, the format switches to a 6-digit “SCHOOL_ID”. The “UNIT_ID” field has been retained for years 2007-08 through 2010-11, which can be used as crosswalk to link earlier years to later ones.

School names will vary slightly for a number of schools due to different naming conventions employed in previous years. It is best to use the “SCHOOL_ID” fields when linking/merging historical data. Some school addresses will also change as a result of relocations or co-locations with other schools over the years.

The school locations data set will also have some exceptions. School Type (SCH_TYPE) will vary slightly over the years. Generally, schools will be categorized as either an elementary, middle, high school (all District-operated), charter, contract, or alternative.
For more information, please email datagovernance@cps.edu.

With almost eleven years of historical data and more than one currently active license for every five City residents, Business Licenses is one of the most popular datasets on the Chicago Open Data Portal and a key resource for understanding economic activity.  However, a known limitation has been that the License Code and License Description sometimes do not make it clear what the business actually does.

We have now been able to go deeper into the system the Department of Business Affairs & Consumer Protection uses to manage the tens of thousands of licenses issued or renewed every year to add Business Activities (and corresponding Business Activity IDs useful for quick filtering) to many license records.  For example, the “Limited Business License” that makes up almost 40 percent of active licenses is, admittedly, not terribly descriptive.  With the new Business Activities field, one can distinguish Hair Services, Tax Preparation, Car Washes, and the many other types of business activity that are recognizable to most people potentially shopping at these businesses.

It is important to note that some business licenses cover more than one type of Business Activity.  In these cases, all available activities (and, again, corresponding codes) are listed in the columns, separated by the “pipe” character (|).

With the addition of this more-specific information on business activities of each license, we have removed addresses from some licenses where that information might unreasonably compromise privacy, currently fewer than 0.05 percent of all license records.

As a reminder of a longstanding feature that might be overlooked, the most useful records for many purposes are the currently active licenses (as opposed to expired ones). A filtered list of just these licenses is available as both a table and a map.

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City of Chicago is continue to build an outstanding technical team and there are openings ranging from senior leadership, GIS, and database administration.

Working for the city provides a number of excellent benefits, such as:

  • Make a direct impact on the 2.8 million residents and over 46 million visitors to Chicago.
  • Modernize government processes for the 21st century, which has included paperless reform, driving the use of modern tools, and
  • Understand how Chicago functions and drive changes to improve efficiency and quality of life.
  • Excellent benefits

Take a look at the openings below and apply today.

Array of Things Node

The Array of Things has reached another milestone.  This week, the final Privacy and Governance Policies were published on the project website.  The final policies, along with detailed responses to 80 comments and the engagement report, can be found at https://arrayofthings.github.io/privacypolicy.html   This step in the AoT project invited the public to provide comments and ask questions about how the data collected by the sensor nodes will be protected and managed.  They were provided with several means to engage with the City, University of Chicago and Argonne National Laboratory.  The project partners have responded to each comment and shared all of the details of the engagement process, along with lessons learned.  This information will serve as a foundation for future public engagement as the Array of Things nodes are installed across the City.

Building Violations DataLense


One of the most defining characteristics of any city is its buildings. They help define the physical character and aesthetic of any city. A USA Today reader poll put Chicago’s skyline as the second-best in the United States. Buildings go beyond the downtown and into our neighborhoods to serve a greater function to also house and shelter us. So it’s also important to make sure these buildings are safe and cared for, which is accomplished by the City of Chicago’s Department of Buildings which inspects and sometimes issues violations for buildings failing to meet a standard for quality and safety.

Several years ago, Chicago published building violations data on the data portal. Last year, the city began publishing a list of problematic landlords and a list of building code scofflaws. Today, we’ve expanded building safety data on the open data portal by releasing administrative hearings data for ordinance violations issued by the Department of Buildings on the open data portal.


"Taste of Chicago Blue Hour" by Justin Kern and licensed under Creative Commons Attribution-NonCommercial-NoDerivs 2.0 Generic (CC BY-NC-ND 2.0)

Chicago finished another phase on its commitment for paperless permits. You can now apply for business permits completely online with no need to follow-up at City Hall.

Chicago’s food inspection team uses a free, open source predictive algorithm to dispatch food inspectors. But it’s when a small start-up used the code for other governments is when it got interesting.

The city’s Chief Data Officer, Tom Schenk, spoke at Amazon Web Service’s DC Summit about OpenGrid and how it helps provide greater transparency and improves city operations.

City of Chicago is big user and producer of open source software, including for the R statistical suite. Watch one of the city’s data scientists gave a talk at the worldwide R user meeting on the city analytics projects.

Another month means another version of OpenGrid is available for the public. This month, the release includes some usability improvements and some technical API improvements. For developers, you can download OpenGrid v1.1.0 from the GitHub page.

AT&T named Chicago one of of the spotlight cities for AT&T’s smart city framework. As part of that, AT&T will be the wireless network used by the Array of Things to carry data from each sensor to the open data portal.

Image credits: “Taste of Chicago Blue Hour” by Justin Kern and licensed under Creative Commons Attribution-NonCommercial-NoDerivs 2.0 Generic (CC BY-NC-ND 2.0)

City of Chicago’s data science team is a big fan of open source software, including the venerable R statistical programming language. Attendees of the annual UseR! (use R) conference were able to see how we used R to predict where to send food inspectors in Chicago. Take a look at Gene Leynes, a data scientist for the City of Chicago, discuss the project at a lightening talk.


Banner image credit: The Hunt by Edsel Little and licensed under Creative Commons Attribution-ShareAlike Generic 2.0 (CC BY-SA 2.0)