Mobility Data Viz Sources

Jan 28, 2015

Sources and Documentation for CMAP Mobility Data Visualizations

Below are details of where the data content for CMAP's Mobility visualizations originated. For additional details, please contact us.

CMAP would like to thank Terry Evans for the use of aerial photography from her book Revealing Chicago.

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Rail
Data source: The rail system visualized is the rail network of the National Transportation Atlas database. The estimated mileage is track-miles obtained from the Chicago Transit Authority (224 miles); and a 2011 track shapefile obtained from the Illinois Commerce Commission (ICC). Metra track-miles total 1,155. The remainder, 2,486 track-miles, is freight-only.
Process: The ICC shapefile was clipped to the CMAP region. The segment lengths were recalculated, then summed for the region.
Additional resources: Additional transit data is available from the Regional Transit Authority Mapping and Statistics website.

Roads
Data source: The road system visualized is comprised of arterials and expressways in the Illinois Roadway Information System. Basic IRIS road data is posted in zipped shapefile format. IRIS metadata is posted in the IRIS manual at . Mileage total is the sum of District 1 mileage plus Kendall County from Table HS-4 in the 2013 annual IDOT Highway and Street Mileage Statistics Report, Table HS-4. These sum to 29,788. CMAP planning area townships in Grundy and DeKalb Counties are not included in this total.
Process: The IRIS shapefile was queried to include only arterials and expressways.
Additional resources: Additional highway data is available from the Illinois Department of Transportation's Highway System Page, which includes tabs on the bottom of the page for interactive data queries, reports, and maps.

Roads

Congestion
Data Sources:

  • Highway speeds from vehicle probes: National Performance Measure Research Dataset (NPMRDS), a HERE dataset made available to states and MPOs through the Freight Management and Operations Program of the Federal Highway Administration. FHWA and HERE.
  • Geography: HERE road database, also made available as part of the NPMRDS.

Process: CMAP calculated average speeds for 5-minute increments using the HERE vehicle probe data collected every five minutes for the period from April 2012 – June 2012 and July 2013 – August 2014. Data is aggregated at the "Traffic Message Code" level on the HERE road database.
Notice: This material is based upon work supported by the Federal Highway Administration under contract number DTFH-13-C-00012. Any opinions, findings, and conclusions or recommendations expressed in this publication are those of the author(s) and do not reflect the views of the Federal Highway Administration.
Additional resources: CMAP uses the NPMRDS dataset for performance-based programming. Sample maps depicting highway performance measures are available. Congestion in the region has been increasing 5 percent annually for 30 years, according to the Texas Transportation Institute (TTI).  TTI data showed the region's average commuter spent 18 hours stuck in traffic during 1982;  by 2012, that average had climbed to 71 hours per year.

 

Ride Quality
Data sources:

  • International Roughness Index and Condition Rating Survey: IDOT's Illinois Roadway Information System (IRIS). CMAP obtained a special version of the IRIS database that includes pavement roughness and condition data. Illinois Tollway data are not included in this file, so are not included in the analysis. Basic IRIS road data is posted in zipped shapefile format. IRIS metadata is posted in the IRIS manual.
  • CMAP Bicycle Level of Service (BLOS) and Pedestrian Level of Service (PLOS). Level of service model inputs, including such items as outside lane widths, presence or absence of sidewalks, pedestrian buffer areas, and speed limits were collected in the field as part of the CMAP Soles and Spokes planning process (2002) and, for the 10-year followup, as part of CMAP's summer field data collection program (2012-2013). Data from Google Streetview and IRIS supplemented field data collection. For a detailed explanation of these level of service models, see Appendix D of the Existing Conditions Report.

Process:

  • International Roughness Index and Condition Rating Survey: CMAP calculated mileage-weighted average values by county and functional class. Illinois Tollway data was not included.
  • BLOS and PLOS: View 2002 field data collection and analysis process and a summary of the 2012-2013 process, including the formulas used.

Additional resources:

  • Ride quality and pavement condition performance measurement is expected to be required soon for the National Highway System, with a process to establish mandatory targets. Recently proposed regulations on how we will measure pavement conditions are available.
  • Visit CMAP's Bicycle and Pedestrian web page for information on bicycle and pedestrian transportation planning.
     

Bridge Condition
Data source: National Bridge Inventory (NBI), 2014. NBI data can be downloaded by state.
Process: No substantial data processing was required for the NBI data.
Additional resources:

  • View more information on the National Bridge Inventory.
  • Bridge condition performance measurement is expected to be required soon for the National Highway System, with a process to establish mandatory targets. Recent proposed regulations on how we will measure bridge conditions are available.

Transit

Transit Access
Data source: The CMAP Access to Transit Index data is available.
Processing: No additional processing was required for the data.
Additional resources: View documentation for the 2014 update to the access to transit index.
 

Ridership
Data source:

  • Chicago Transit Authority ridership: 2013 weekday ridership by line was obtained from the CTA's 2013 annual ridership report (p. 24). 2013 station-level data was downloaded and mote that the station-level data represents "entries," not boardings; cross-platform transfers are not included in "entry" data mapped here. The line-level data and CTA total ridership includes cross-platform transfers.
  • Metra ridership: 2014 ridership was obtained directly from Metra. The data was from the 2014 Boarding and Alighting Count, which is still being processed and evaluated. This data is expected to be publicly available in 2015 at http://www.rtams.org/rtams/metraHistoricalRidership.jsp.
  • Geography: The geography is schematic, not representing a map with a set scale and direction. The intent of the schematic diagram is to include all of the stations in a single page while still making closely-spaced central stations separate and distinct for viewing.

Processing: No substantial data processing was required for the ridership data.
Additional resources: Additional ridership data, including bus ridership and historical rail ridership, is on the Regional Transit Authority's RTAMS website.
 

Maintenance
Data source: The estimates for capital needs and the percent of assets in a state of good repair are from the Regional Transit Aurthority's 2013 Capital Asset Condition Assessment.
Processing: No additional processing was required.
Additional resources: As the CMAP transportation data visualization site was being developed, a 2014 Capital Asset Condition Assessment was released. The revised assessment estimates the capital backlog slightly lower, at $19.5 billion, and but a higher ongoing 10-year capital need at $16.6 billion. 

Freight

Crossing Delay
NOTE:  This map omits data on crossing delays at four crossings that have been affected significantly since the Canadian National Railway (CN) acquisition of the Elgin, Joliet, and Eastern Railway (EJ&E). Because the National Highway-Rail Crossing Inventory entries for those crossings may not reflect current conditions, CMAP has elected to omit the following: Lake Zurich Road, Northwest Highway (US 14), Hough Street (IL 59) in Lake County, and Main Street (Lake Cook Road) in Cook County.

Data source: Estimates of motorist delay at highway-rail grade crossings was prepared by the Illinois Commerce Commission (ICC) for the Chicago Metropolitan Agency for Planning. The data was provided to CMAP and is posted in shapefile format on the CMAP data sharing hub, https://datahub.cmap.illinois.gov/dataset/motorist-delay-at-highway-rail-grade-crossings-northeastern-illinois-2002-and-2011. The data represents the historical 6-county region (Kendall, Grundy, or DeKalb Counties are not included in the dataset).
Processing: Delay estimates are calculated for each at-grade crossing based on such factors as the highway volume; the volume of trains crossing the highway (commuter and freight trains); the estimated length of trains; the average speed of the trains by type of train; and the proximity of commuter stations and freight terminals or switching yards.
Additional resources:

CREATE
Data Source: Data was provided by CREATE Program partners.
Processing: No additional processing of the data was required.
Additional resources: The Chicago Region Environmental and Transportation Efficiency (CREATE) Program maintains a project website with up-to-date project information. The site includes links to on-going environmental and engineering studies and construction updates: http://www.createprogram.org/projects.htm.

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