The Chicago region traffic congestion scans were created by averaging five minute speed data obtained from freeway loop detectors, radar, and mobile technology data. The traffic scans display average speed on a freeway corridor as a function of time of day (the x-axis) and location (the y-axis) along a freeway corridor.
I-55 Stevenson Expressway, Lake Shore Drive to I-294
Jan 28, 2014
I-55 Stevenson Expressway (Lake Shore Drive to I-294) Congestion and Crash Scans
Congestion Scans
I-55, Stevenson Expressway, from US 41/Lake Shore Drive to I-294 Tri-State Tollway. Congestion Scan, 2016. Showing average speed by milepost by time of day.
Note: for best viewing, in Chrome, right-click on the graphic, then open in a new tab. In other browsers, the image may be saved or downloaded as a PDF below.
Download high-resolution PDF (all vehicles, as shown above)
Download high-resolution PDF (trucks only)
I-55, Stevenson Expressway from US 41/Lake Shore Drive to I-294 Congestion Scan, 2011. Showing average speed by milepost by time of day.
I-55, Stevenson Expressway from US 41/Lake Shore Drive to I-294 Congestion Scan, 2009. Showing average speed by milepost by time of day.
I-55, Stevenson Expressway from US 41/Lake Shore Drive to I-294 Congestion Scan, 2007. Showing average speed by milepost by time of day.
Crash Scans
I-55, US 41 to I-90/94 Crash Scan, 2008-12. Showing number of crash rates per 100 million vehicle miles traveled.
I-55, I-90/94 to I-294 Crash Scan 2008-12. Showing number of crash rates per 100 million vehicle miles traveled.
Performance Data
Non-holiday Tuesdays, Wednesdays, and Thursdays:
South-bound I-55/Stevenson Expressway
Measure | 2007 | 2008 | 2009 | 2010 | 2011 |
---|---|---|---|---|---|
Free-Flow Travel Time (Minutes) |
15.94 | 15.98 | 16.20 | 16.24 | 16.30 |
Average AM Peak-Period Travel Time (Minutes) |
20.88 | 21.31 | 21.18 | 21.78 | 21.97 |
AM Travel Time Index | 1.31 | 1.33 | 1.31 | 1.34 | 1.35 |
Average PM Peak-Period Travel Time (Minutes) |
34.02 | 37.91 | 35.44 | 33.67 | 35.00 |
PM Travel Time Index |
2.13 |
2.37 |
2.19 |
2.07 | 2.15 |
AM Peak-Period 95th Percentile Travel Time (Minutes) |
28.20 |
30.68 |
29.79 |
33.34 | 31.43 |
AM Peak-Period |
1.76 |
1.92 |
1.84 |
2.05 | 1.93 |
PM Peak-Period 95th Percentile Travel Time (Minutes) |
59.03 |
65.96 |
60.78 |
55.01 | 53.90 |
PM Peak-Period Planning Time Index |
3.72 |
4.13 |
3.75 |
3.39 | 3.31 |
Congested Hours |
12.29 |
12.66 |
11.96 |
11.82 | 12.37 |
North-bound I-55/Stevenson Expressway
Measure |
2007 |
2008 |
2009 |
2010 | 2011 |
---|---|---|---|---|---|
Free-Flow Travel Time (Minutes) |
15.76 |
15.76 |
16.06 |
16.33 | 16.33 |
Average AM Peak-Period Travel Time (Minutes) |
36.15 |
33.04 |
31.10 |
30.87 | 30.67 |
AM Travel Time Index |
2.29 |
2.10 |
1.94 |
1.89 | 1.88 |
Average PM Peak-Period Travel Time (Minutes) |
22.81 |
24.36 |
22.68 |
24.29 | 23.12 |
PM Travel Time Index |
1.45 |
1.55 |
1.41 |
1.49 | 1.42 |
AM Peak-Period 95th Percentile Travel Time (Minutes) |
53.09 |
50.80 |
48.66 |
50.12 | 49.96 |
AM Peak-Period |
3.37 |
3.22 |
3.03 |
3.07 | 3.06 |
PM Peak-Period 95th Percentile Travel Time (Minutes) |
34.02 |
39.43 |
33.59 |
35.20 | 34.22 |
PM Peak-Period Planning Time Index |
2.16 |
2.50 |
2.09 |
2.16 | 2.10 |
Congested Hours |
12.35 |
12.41 |
11.33 |
11.97 | 12.27 |
About the Data
Data provided by IDOT, Illinois Tollway, and HERE.
Jan 28, 2014
I-55 Stevenson Expressway (Lake Shore Drive to I-294) Congestion and Crash Scans
The Chicago region traffic congestion scans were created by averaging five minute speed data obtained from freeway loop detectors, radar, and mobile technology data. The traffic scans display average speed on a freeway corridor as a function of time of day (the x-axis) and location (the y-axis) along a freeway corridor.
Congestion Scans
I-55, Stevenson Expressway, from US 41/Lake Shore Drive to I-294 Tri-State Tollway. Congestion Scan, 2016. Showing average speed by milepost by time of day.
Note: for best viewing, in Chrome, right-click on the graphic, then open in a new tab. In other browsers, the image may be saved or downloaded as a PDF below.
Download high-resolution PDF (all vehicles, as shown above)
Download high-resolution PDF (trucks only)
I-55, Stevenson Expressway from US 41/Lake Shore Drive to I-294 Congestion Scan, 2011. Showing average speed by milepost by time of day.
I-55, Stevenson Expressway from US 41/Lake Shore Drive to I-294 Congestion Scan, 2009. Showing average speed by milepost by time of day.
I-55, Stevenson Expressway from US 41/Lake Shore Drive to I-294 Congestion Scan, 2007. Showing average speed by milepost by time of day.
Crash Scans
I-55, US 41 to I-90/94 Crash Scan, 2008-12. Showing number of crash rates per 100 million vehicle miles traveled.
I-55, I-90/94 to I-294 Crash Scan 2008-12. Showing number of crash rates per 100 million vehicle miles traveled.
Performance Data
Non-holiday Tuesdays, Wednesdays, and Thursdays:
South-bound I-55/Stevenson Expressway
Measure | 2007 | 2008 | 2009 | 2010 | 2011 |
---|---|---|---|---|---|
Free-Flow Travel Time (Minutes) |
15.94 | 15.98 | 16.20 | 16.24 | 16.30 |
Average AM Peak-Period Travel Time (Minutes) |
20.88 | 21.31 | 21.18 | 21.78 | 21.97 |
AM Travel Time Index | 1.31 | 1.33 | 1.31 | 1.34 | 1.35 |
Average PM Peak-Period Travel Time (Minutes) |
34.02 | 37.91 | 35.44 | 33.67 | 35.00 |
PM Travel Time Index |
2.13 |
2.37 |
2.19 |
2.07 | 2.15 |
AM Peak-Period 95th Percentile Travel Time (Minutes) |
28.20 |
30.68 |
29.79 |
33.34 | 31.43 |
AM Peak-Period |
1.76 |
1.92 |
1.84 |
2.05 | 1.93 |
PM Peak-Period 95th Percentile Travel Time (Minutes) |
59.03 |
65.96 |
60.78 |
55.01 | 53.90 |
PM Peak-Period Planning Time Index |
3.72 |
4.13 |
3.75 |
3.39 | 3.31 |
Congested Hours |
12.29 |
12.66 |
11.96 |
11.82 | 12.37 |
North-bound I-55/Stevenson Expressway
Measure |
2007 |
2008 |
2009 |
2010 | 2011 |
---|---|---|---|---|---|
Free-Flow Travel Time (Minutes) |
15.76 |
15.76 |
16.06 |
16.33 | 16.33 |
Average AM Peak-Period Travel Time (Minutes) |
36.15 |
33.04 |
31.10 |
30.87 | 30.67 |
AM Travel Time Index |
2.29 |
2.10 |
1.94 |
1.89 | 1.88 |
Average PM Peak-Period Travel Time (Minutes) |
22.81 |
24.36 |
22.68 |
24.29 | 23.12 |
PM Travel Time Index |
1.45 |
1.55 |
1.41 |
1.49 | 1.42 |
AM Peak-Period 95th Percentile Travel Time (Minutes) |
53.09 |
50.80 |
48.66 |
50.12 | 49.96 |
AM Peak-Period |
3.37 |
3.22 |
3.03 |
3.07 | 3.06 |
PM Peak-Period 95th Percentile Travel Time (Minutes) |
34.02 |
39.43 |
33.59 |
35.20 | 34.22 |
PM Peak-Period Planning Time Index |
2.16 |
2.50 |
2.09 |
2.16 | 2.10 |
Congested Hours |
12.35 |
12.41 |
11.33 |
11.97 | 12.27 |
About the Data
Data provided by IDOT, Illinois Tollway, and HERE.