GTIS Travel Time Report #2
Statistics for Agency:IL-IDOTD8 Route:IL-159

   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
NBI-70I-2703.305.245.7973.1588.3878.2063.1356.7887.3687.2477.650.21
NBI-64I-708.1112.2714.7669.8884.9191.4154.8352.5868.6997.0575.151.07
NBOverall11.4017.5120.5571.5186.6484.8158.9854.6878.0292.1476.402.30
SBI-270I-703.335.135.7774.3888.7590.2265.3855.5981.3788.6378.903.65
SBI-70I-648.0912.5614.7373.8986.0887.4262.4954.9368.2796.9677.004.25
SBOverall11.4217.7020.5074.1387.4188.8263.9355.2674.8292.8077.952.30
Overall22.8335.2141.0572.8287.0386.8161.4654.9776.4292.4777.182.30
Cells are highlighted red when they decrease by more than -5.65 percentage points which represents the 5th percentile of monthly changes at this aggregation from 2017-2025.
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