Great Lakes Regional Transportation Operations Coalition

Mid-America Scanner

Interstate Mobility Performance Scanning Tool

Motivated by multistate mobility performance management, especially for freight movement, GLRTOC has developed a monthly scanning tool utilizing data from the NPMRDS. Each month as new data are available, all 22+ thousand miles of interstate within the ten-state Mid-America region are scanned for anomalies. Through different methods and algorithms, major disruptions to mobility from incidents, new work zones, or winter weather are picked up, reported, and displayed on maps.

Data are established as a time series for each TMC (panel data), and various normalized Z scores are assessed, scanning for only the largest disruptions and anomalies. Borrowing from other disciplines, a control chart approach is applied to cull signals from noise, listening for anomalies of different durations and geographic extents. Short term dramatic reductions in speed – and especially observations – are symptomatic of major incidents and closures; longer term (e.g., multiple day) reductions in median or higher speeds often indicate high impact work zones; and widespread effects often signal winter weather impacts.

GLRTOC uses these results in their work to improve multistate mobility performance management. These presentation slides from June 2015 (PDF 4.7 MB) also show additional charts and illustrations.

The development of this continues, but some early examples follow. Scroll down for animated visualizations by different speed percentiles. Click on any image to see it larger and by itself. Individual images for each month and measure are listed at the bottom.

Observations or Count Score
This first image illustrates where significant drops in throughput occurred, by month.
by_month_count

The following animation as an example of visualizing impacts by day. This one shows where significant drops in throughput occurred in February 2015 – note the winter weather on February 1st, the 5th snowiest day on record for the Chicago area.
count_day

20th Percentile Speed
by_month_speed20

50th Percentile (Median) Speed
by_month_speed50

80th Percentile Speed
by_month_speed80


Results by Month and Measure

Each month lists an image showing the 20th percentile speed score, 50th, and 80th, followed by the data count score.

October 2016
20th201610spd2050th201610spd5080th201610spd80count201610count

September 2016
20th201609spd2050th201609spd5080th201609spd80count201609count

August 2016
20th201608spd2050th201608spd5080th201608spd80count201608count

July 2016
20th201607spd2050th201607spd5080th201607spd80count201607count

June 2016
20th201606spd2050th201606spd5080th201606spd80count201606count

May 2016
20th201605spd2050th201605spd5080th201605spd80count201605count

April 2016
20th201604spd2050th201604spd5080th201604spd80count201604count

March 2016
20th201603spd2050th201603spd5080th201603spd80count201603count

February 2016
20th201602spd2050th201602spd5080th201602spd80count201602count

January 2016
20th201601spd2050th201601spd5080th201601spd80count201601count

December 2015
20th201512spd2050th201512spd5080th201512spd80count201512count

November 2015
20th201511spd2050th201511spd5080th201511spd80count201511count

October 2015
20th201510spd2050th201510spd5080th201510spd80count201510count

September 2015
20th201509spd2050th201509spd5080th201509spd80count201509count

August 2015
20th201508spd2050th201508spd5080th201508spd80count201508count

July 2015
20th201507spd2050th201507spd5080th201507spd80count201507count

June 2015
20th201506spd2050th201506spd5080th201506spd80count201506count

May 2015
20th201505spd2050th201505spd5080th201505spd80count201505count

April 2015
20th201504spd2050th201504spd5080th201504spd80count201504count

March 2015
20th201503spd2050th201503spd5080th201503spd80count201503count

February 2015
20th201502spd2050th201502spd5080th201502spd80count201502count

January 2015
20th201501spd2050th201501spd5080th201501spd80count201501count

December 2014
20th201412spd2050th201412spd5080th201412spd80count201412.count

November 2014
20th201411spd2050th201411spd5080th201411spd80count201411.count


An older prototype map