GTIS Travel Time Report #2
Statistics for Agency:IL-IDOTD8 Route:I-55

   Year        Month
Year: 2023 Month: January
Direction Segment Start Segment End
Total Length (mi)
  • Total length of all segments for the route listed (may include overlapping segments)
Total Travel Time, GTIS (min)
  • Average total travel time for all segments as reported by the Gateway Traveler Information System (GTIS)
Total Travel Time, NPMRDS (min)
  • Average total travel time for all segments as reported by the National Performance Management Research Data Set (NPMRDS)
Similarity 1 (%)
  • Based on Normalized Root Mean Square Error (NRMSE)
  • Shows how similar the values are / error in measurements
Similarity 2 (%)
  • Based on Mean Absolute Percentage Error (MAPE)
  • Shows how similar the values are / error in measurements
  • Deviation between data points in terms of percentage, effected largely by overforecasts
Abnormality (%)
  • Based on data lying outside of three standard deviations from the mean versus what would normally be expected
  • Affected by GTIS and NPMRDS evenly
Association (%)
  • Based on correlation coefficient between datasets
  • Can you predict one value based on the other
Inequality (%)
  • Based on Theil statistics for the data
  • Suite of four statistics commonly used to compare travel time data
  • Measuring covariance, variance, and bias
Bias (%)
  • Based on Theil bias statistic only
Omission (%)
  • Based on data availability
  • Large amounts of unavailable data results in lower score
Overall (%)
  • Weighted average of the seven intermediate statistics
Change From Last Month(%)
  • Percent change in overall score from previous month
NBIL-111I-255N/AN/AN/AN/AN/AN/AN/AN/AN/AN/AN/AN/A
NBI-64IL-111N/AN/AN/AN/AN/AN/AN/AN/AN/AN/AN/AN/A
NBMississippi RiverI-64N/AN/AN/AN/AN/AN/AN/AN/AN/AN/AN/AN/A
NBI-255Keebler RdN/AN/AN/AN/AN/AN/AN/AN/AN/AN/AN/AN/A
NBI-255I-2709.458.338.6394.8296.1278.3596.0879.3054.91100.0088.604.35
NBMississippi RiverIL-32.752.752.2677.2377.7769.9269.3765.858.50100.0070.11-0.44
NBSt Clair AveI-2557.216.506.4292.5596.8269.2885.6094.7697.45100.0092.05-1.67
NBI-270IL-413.8311.4611.2195.7697.0696.9380.7987.3471.57100.0091.871.00
NBOverall33.2429.0428.5290.0991.9478.6282.9681.8158.11100.0085.66-0.03
SBIL-111I-64N/AN/AN/AN/AN/AN/AN/AN/AN/AN/AN/AN/A
SBKeebler RdI-255N/AN/AN/AN/AN/AN/AN/AN/AN/AN/AN/AN/A
SBI-46Mississippi RiverN/AN/AN/AN/AN/AN/AN/AN/AN/AN/AN/AN/A
SBI-255IL-111N/AN/AN/AN/AN/AN/AN/AN/AN/AN/AN/AN/A
SBI-270I-2559.458.088.3995.4496.2093.7176.2777.6536.89100.0086.361.01
SBI-255St Clair Ave7.276.416.6495.7896.4878.3587.7377.4235.42100.0085.96-3.36
SBIL-3Mississippi River2.572.762.5283.4890.3044.9194.7164.4266.16100.0080.47-1.25
SBIL-4I-27013.8311.3811.1096.4997.1984.7884.2482.5150.85100.0088.660.13
SBOverall33.1328.6428.6592.8095.0575.4485.7475.5047.33100.0085.36-0.03
Overall66.3657.6857.1791.4493.4977.0384.3578.6652.72100.0085.51-0.03
Cells are highlighted red when they decrease by more than -6.14 percentage points which represents the 5th percentile of monthly changes at this aggregation from 2017-2025.
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