Answers to frequently asked questions about the City of Chicago Data Portal.

This dataset includes information about building permits issued by the City of Chicago from 2006 to the present, excluding permits that have been voided or revoked after issuance. Most types of permits are issued subject to payment of the applicable permit fee. Work under a permit may not begin until the applicable permit fee is paid.

For more information about building permits, see http://www.chicago.gov/permit.

This dataset contains the current estimated congestion for the 29 traffic regions. For a detailed description, please go to https://tas.chicago.gov, click the About button at the bottom of the page, and then the MAP LAYERS tab.

The Chicago Traffic Tracker estimates traffic congestion on Chicago’s arterial streets (non-freeway streets) in real-time by continuously monitoring and analyzing GPS traces received from Chicago Transit Authority (CTA) buses. Two types of congestion estimates are produced every 10 minutes: 1) by Traffic Segments and 2) by Traffic Regions or Zones. Congestion estimates by traffic segments gives observed speed typically for one-half mile of a street in one direction of traffic. Traffic Segment level congestion is available for about 300 miles of principal arterials. Congestion by Traffic Region gives the average traffic condition for all arterial street segments within a region. A traffic region is comprised of two or three community areas with comparable traffic patterns. 29 regions are created to cover the entire city (except O’Hare airport area).

There is much volatility in traffic segment speed. However, the congestion estimates for the traffic regions remain consistent for a relatively longer period. Most volatility in arterial speed comes from the very nature of the arterials themselves. Due to a myriad of factors, including but not limited to frequent intersections, traffic signals, transit movements, availability of alternative routes, crashes, short length of the segments, etc. Speed on individual arterial segments can fluctuate from heavily congested to no congestion and back in a few minutes. The segment speed and traffic region congestion estimates together may give a better understanding of the actual traffic conditions.

This lists datasets published by CTA in the City of Chicago Data Portal.

The Chicago Building Energy Use Benchmarking Ordinance calls on existing municipal, commercial, and residential buildings larger than 50,000 square feet to track whole-building energy use, report to the City annually, and verify data accuracy every three years. The law, which was phased in from 2014-2017, covers less than 1% of Chicago’s buildings, which account for approximately 20% of total energy used by all buildings. For more details, including ordinance text, rules and regulations, and timing, please visit www.CityofChicago.org/EnergyBenchmarking

The ordinance authorizes the City to share property-specific information with the public, beginning with the second year in which a building is required to comply.

The dataset represents self-reported and publicly-available property information by calendar year. Please note that the "Data Year" column refers to the year to which the data apply, not the year in which they were reported. That column and filtered views under "Related Content" can be used to isolate specific years.

This dataset is a listing of all active City of Chicago employees, complete with full names, departments, positions, employment status (part-time or full-time), frequency of hourly employee –where applicable—and annual salaries or hourly rate. Please note that "active" has a specific meaning for Human Resources purposes and will sometimes exclude employees on certain types of temporary leave. For hourly employees, the City is providing the hourly rate and frequency of hourly employees (40, 35, 20 and 10) to allow dataset users to estimate annual wages for hourly employees. Please note that annual wages will vary by employee, depending on number of hours worked and seasonal status. For information on the positions and related salaries detailed in the annual budgets, see https://www.cityofchicago.org/city/en/depts/obm.html

Data Disclosure Exemptions: Information disclosed in this dataset is subject to FOIA Exemption Act, 5 ILCS 140/7 (Link:https://www.ilga.gov/legislation/ilcs/documents/000501400K7.htm)

Records from the Crimes - 2001 to Present dataset for the indicated year.

Please see the description section of the full dataset for further information about the data.

Permits issued by the Department of Buildings in the City of Chicago from 2006 to the present. The dataset for each year contains more than 65,000 records/rows of data and cannot be viewed in full in Microsoft Excel. Therefore, when downloading the file, select CSV from the Export menu. Open the file in an ASCII text editor, such as Wordpad, to view and search. Data fields requiring description are detailed below. PERMIT TYPE: "New Construction and Renovation" includes new projects or rehabilitations of existing buildings; "Other Construction" includes items that require plans such as cell towers and cranes; "Easy Permit" includes minor repairs that require no plans; "Wrecking/Demolition" includes private demolition of buildings and other structures; "Electrical Wiring" includes major and minor electrical work both permanent and temporary; "Sign Permit" includes signs, canopies and awnings both on private property and over the public way; "Porch Permit" includes new porch construction and renovation (defunct permit type porches are now issued under "New Construction and Renovation" directly); "Reinstate Permit" includes original permit reinstatements; "Extension Permits" includes extension of original permit when construction has not started within six months of original permit issuance. WORK DESCRIPTION: The description of work being done on the issued permit, which is printed on the permit. PIN1 – PIN10: A maximum of ten assessor parcel index numbers belonging to the permitted property. PINs are provided by the customer seeking the permit since mid-2008 where required by the Cook County Assessor’s Office. CONTRACTOR INFORMATION: The contractor type, name, and contact information. Data includes up to 15 different contractors per permit if applicable.

Data Owner: Buildings.

Time Period: January 1, 2006 to present.

Frequency: Data is updated daily.

Related Applications: Building Data Warehouse (https://webapps.cityofchicago.org/buildingviolations/violations/searchaddresspage.html).

All vendor payments made by the City of Chicago from 1996 to present. Payments from 1996 through 2002 have been rolled-up and appear as "2002." Total payment information is summarized for each vendor and contract number for data older than two years. These data are extracted from the City’s Vendor, Contract, and Payment Search.

Time Period: 1996 to present.

Frequency: Data is updated daily.

Related Applications: City of Chicago Vendor, Contract, and Payments Search (http://webapps.cityofchicago.org/VCSearchWeb/org/cityofchicago/vcsearch/controller/payments/begin.do?agencyId=city).

City boundary of Chicago. The data can be viewed on the Chicago Data Portal with a web browser. However, to view or use the files outside of a web browser, you will need to use compression software and special GIS software, such as ESRI ArcGIS (shapefile) or Google Earth (KML or KMZ).

FOIA requests received by the Office of the Chicago City Clerk as of May 1, 2010

This dataset is historical. For recent data, we recommend using https://chicagotraffictracker.com. -- Average Daily Traffic (ADT) counts are analogous to a census count of vehicles on city streets. These counts provide a close approximation to the actual number of vehicles passing through a given location on an average weekday. Since it is not possible to count every vehicle on every city street, sample counts are taken along larger streets to get an estimate of traffic on half-mile or one-mile street segments. ADT counts are used by city planners, transportation engineers, real-estate developers, marketers and many others for myriad planning and operational purposes. Data Owner: Transportation. Time Period: 2006. Frequency: A citywide count is taken approximately every 10 years. A limited number of traffic counts will be taken and added to the list periodically. Related Applications: Traffic Information Interactive Map (http://webapps.cityofchicago.org/traffic/).

Contracts and modifications awarded by the City of Chicago since 1993. This data is currently maintained in the City’s Financial Management and Purchasing System (FMPS), which is used throughout the City for contract management and payment. Legacy System Records: Purchase Order/Contract Numbers that begin with alpha characters identify records imported from legacy systems. Records with a null value in the Contract Type field were imported from legacy systems. "Comptroller-Other" Contract Type: Some records where the Contract Type is "COMPTROLLER-OTHER" are ordinance-based agreements and may have start dates earlier than 1993. Depends Upon Requirements Contracts: If the contract Award Amount is $0, the contract is not cancelled, and the contract is a blanket contract, then the contract award total Depends Upon Requirements. A Depends Upon Requirements contract is an indefinite quantities contract in which the City places orders as needed and the vendor is not guaranteed any particular contract award amount.

Blanket vs. Standard Contracts: Only blanket contracts (contracts for repeated purchases) have FMPS end dates. Standard contracts (for example, construction contracts) terminate upon completion and acceptance of all deliverables. These dates are tracked outside of FMPS.

Negative Modifications: Some contracts are modified to delete scope and money from a contract. These reductions are indicated by negative numbers in the Award Amount field of this dataset.

Data Owner: Procurement Services. Time Period: 1993 to present. Frequency: Data is updated daily.

List of City of Chicago licensed Public Chauffeurs, who may operate a licensed Taxicab, Livery, or Pedicab. Horse-Drawn Carriage license historical records appear; but are no longer issued. For questions or issues regarding this dataset, please e-mail BACPPV@cityofchicago.org with chauffeur name, number, and question or issue. For more information on the Public Chauffeur program, please see http://www.cityofchicago.org/city/en/depts/bacp/supp_info/public_chauffeurinformation.html.

FOIA requests received as of January 3, 2011 by the Department of Planning and Development (Department of Housing and Economic Development prior to January 2014).

Small Business Improvement Fund data includes all projects that have received a final grant payment since January, 2001. SBIF uses TIF revenues to provide reimbursement grants to small commercial and industrial businesses and property owners to help fund permanent improvements to their buildings and improve the appearance of their neighborhoods.

Note: This dataset is historical only and there are not corresponding datasets for more recent time periods. For that more-recent information, please visit the Chicago Health Atlas at https://chicagohealthatlas.org.

This dataset contains a selection of 27 indicators of public health significance by Chicago community area, with the most updated information available. The indicators are rates, percents, or other measures related to natality, mortality, infectious disease, lead poisoning, and economic status. See the full description at https://data.cityofchicago.org/api/assets/2107948F-357D-4ED7-ACC2-2E9266BBFFA2.

Chicago Public Library locations, contact information, and usual hours of operation.

Please note that branches may experience short-term closures due to utility interruptions, HVAC problems, and other unforeseen issues. For more up-to-date hours, please see https://chipublib.bibliocommons.com/locations or the Hours & Locations link at the top of any page on https://www.chipublib.org. For current closures, please see https://www.chipublib.org/news/cpl-location-closures.

All vehicles reported by Transportation Network Providers (sometimes called rideshare companies) to the City of Chicago as part of routine reporting required by ordinance. Inclusion of a vehicle in a monthly report indicates that the vehicle was eligible for trips in Chicago in that month for at least one day, regardless of whether it actually provided any rides. If a vehicle is eligible in multiple months, which is common, it will have records in each of these reporting months.

As of the creation of this dataset, there have been four TNPs licensed to operate in Chicago, although never more than three at any given time and currently three. Vehicles reported by more than one company in the same month are combined and the MULTIPLE_TNPS column is marked as TRUE. However, the matching process is imperfect so not all such vehicles are necessarily identified.

Information on last inspection date was not required before September 2017 so will not be found in older records.

The reporting is done on a monthly basis, as indicated in the MONTH_REPORTED column. However, starting in 2018, the reports are batched and files for all three months in a quarter are delivered to the City of Chicago at the end of each quarter. Due to an issue in this transition, some vehicle records for Q2 2018 (April-June) were reported for the quarter as a whole, rather than for individual months. For purposes of this dataset, those records have been assigned to 2018-06 (June). Therefore, some caution in interpreting this month and the quarter as a whole is advised.

The dataset details 2023 Budget Recommendations, which is the line-item budget document proposed by the Mayor to the City Council for approval. Budgeted expenditures are identified by department, appropriation account, and funding type: Local, Community Development Block Grant Program (CDBG), and other Grants. “Local” funds refer to those line items that are balanced with locally-generated revenue sources, including but not limited to the Corporate Fund, Water Fund, Midway and O’Hare Airport funds, Vehicle Tax Fund, Library Fund and General Obligation Bond funds.

This dataset follows the format of the equivalent datasets from past years except that Appropriation Authority and Appropriation Account have changed from Number to Text in order to accommodate non-numeric values.

For more information about the budget process, visit the Budget Documents page: https://www.chicago.gov/city/en/depts/obm/provdrs/budget.html.