GTIS Travel Time Report #2
Statistics for Agency:IL-IDOTD8 Route:IL-157

   Year        Month
Year: 2021 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-64I-705.208.6812.2049.3975.2378.1961.7040.3067.5174.7463.40N/A
NBI-70I-2705.447.2111.9637.1868.3391.2864.0237.9160.0570.7558.78N/A
NBOverall10.6415.8924.1643.2971.7884.7362.8639.1063.7872.7461.09N/A
SBI-270I-705.447.3012.5632.2366.1677.9262.0736.0261.8861.6354.55N/A
SBI-70I-645.218.7110.6143.3980.3792.7958.1034.3889.9974.5765.92N/A
SBOverall10.6516.0123.1737.8173.2785.3560.0835.2075.9468.1060.24N/A
Overall21.2931.9047.3340.5572.5285.0461.4737.1569.8670.4260.66N/A
Cells are highlighted red when they decrease by more than -5.63 percentage points which represents the 5th percentile of monthly changes at this aggregation from 2017-2024.
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