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From page 4... ... 4Context One of key objectives of the SHRP 2 Reliability program research is to develop methods for researchers and practitioners to evaluate the causal factors of travel time unreliability. The Federal Highway Administration (FHWA) Read the entire page →
From page 5... ... 5 Following initial investigation of the relationships between the assembled variables and the calculated reliability metrics, the L03 team proposed two model forms: 1. "A detailed deterministic model that uses all of the data being collected to a maximum degree (data-rich model) Read the entire page →
From page 6... ... 6• Peak period: period of at least 75 min during which is the space mean speed is less than 45 mph • Midday: 11:00 a.m.–2:00 p.m., Monday–Friday • Weekday: All day, Monday–Friday The team selected a natural logarithmic form for the regression model, because it is able to predict a TTI of 1 when the independent variables are 0. Root mean square error (RMSE) Read the entire page →
From page 7... ... 7 collected on 26 freeway segments in the Seattle metropolitan area. Table 1.5 shows the validation error (the percentage difference between the measured and the predicted values) Read the entire page →
From page 8... ... 8Table 1.5. L03 Validation Errors Roadway Section Peak Period Weekday Data-Poor Mean 80th 95th Mean 80th 95th 80th 95th I-405 Bellevue northbound +30 to 40% Over +40% Over +40% Under +10% +10 to 20% +10 to 20% Under +10% +20 to 30% I-405 Eastgate northbound +10 to 20% +10 to 20% +30 to 40% NA Under +10% Under +10% Under +10% +30 to 40% I-405 Eastgate southbound -10 to 20% -10 to 20% Under -10% -10 to 20% -10 to 20% -10 to 20% Under +10% -20 to 30% I-405 Kennydale southbound -10 to 20% -10 to 20% -10 to 20% -10 to 20% -30 to 40% -30 to 40% Under -10% -20 to 30% I-405 Kirkland northbound Under +10% Under +10% +20 to 30% Under +10% Under +10% +20 to 30% +10 to 20% +30 to 40% I-405 Kirkland southbound Under -10% Under +10% +10 to 20% Under -10% Under +10% +20 to 30% Under +10% +30 to 40% I-405 North northbound Under +10% Under +10% +20 to 30% Under +10% Under +10% +10 to 20% Under +10% +20 to 30% I-405 North southbound -30 to 40% Over -40% Over -40% Under +10% -10 to 20% -20 to 30% -10 to 20% Over -40% I-405 South northbound -30 to 40% -30 to 40% -20 to 30% -20 to 30% Over -40% Over -40% -10 to 20% -20 to 30% I-405 South southbound Under +10% Under +10% +10 to 20% +10 to 20% +20 to 30% +10 to 20% Under +10% +10 to 20% I-5 Everett northbound Under +10% Under -10% -10 to 20% Under +10% Under +10% -30 to 40% +20 to 30% Over -40% I-5 Everett southbound +20 to 30% +20 to 30% +30 to 40% Under +10% +10 to 20% +20 to 30% Under +10% Under +10% I-5 Lynnwood northbound +10 to 20% +20 to 30% Under -10% Under +10% Under +10% -10 to 20% Under +10% +20 to 30% I-5 Lynnwood southbound Under -10% Under -10% -10 to 20% Under -10% Under +10% -20 to 30% +10 to 20% -30 to 40% I-5 South northbound +10 to 20% +20 to 30% +30 to 40% Under +10% +10 to 20% Under +10% +10 to 20% +30 to 40% I-5 South southbound +10 to 20% Under +10% +20 to 30% Under +10% Under +10% +20 to 30% +10 to 20% +30 to 40% I-5 Tukwila northbound +20 to 30% +10 to 20% +10 to 20% Under +10% Under +10% Under +10% Under +10% +20 to 30% I-5 Tukwila southbound Over +40% Over +40% Over +40% Under +10% Under +10% +20 to 30% Under +10% Under +10% I-90 Bellevue westbound +20 to 30% +30 to 40% +30 to 40% Under +10% Under +10% +10 to 20% +10 to 20% +20 to 30% I-90 Bridge eastbound +10 to 20% Under +10% Under +10% Under +10% Under +10% +20 to 30% Under +10% +30 to 40% I-90 Bridge westbound Under -10% -10 to 20% -10 to 20% Under -10% Under +10% -10 to 20% +10 to 20% -10 to 20% I-90 Issaquah westbound +10 to 20% +10 to 20% +10 to 20% Under +10% Under +10% +10 to 20% Under +10% +20 to 30% SR 167 Auburn northbound Under -10% Under -10% Under +10% Under -10% -10 to 20% +20 to 30% Under -10% -20 to 30% SR 167 Auburn southbound -10 to 20% -20 to 30% -20 to 30% Under -10% -10 to 20% -30 to 40% Under +10% -20 to 30% SR 167 Renton northbound Under +10% +20 to 30% -10 to 20% Under +10% +10 to 20% -20 to 30% Under +10% +20 to 30% SR 167 Renton southbound Under +10% Under +10% -10 to 20% Under +10% Under +10% -10 to 20% Under +10% +20 to 30% Note: NA = not available. Read the entire page →
From page 9... ... 9 • Appendix B: Validation Plan is a technical report outlining the data collection and analysis strategy for validating the L03 data-rich and data-poor models. • Appendix C: Data-Rich Validation is a technical memorandum containing detailed validation results for the data-rich models. Read the entire page →

From page 4...

... 4Context One of key objectives of the SHRP 2 Reliability program research is to develop methods for researchers and practitioners to evaluate the causal factors of travel time unreliability. The Federal Highway Administration (FHWA)

Read the entire page →

From page 5...

... 5 Following initial investigation of the relationships between the assembled variables and the calculated reliability metrics, the L03 team proposed two model forms: 1. "A detailed deterministic model that uses all of the data being collected to a maximum degree (data-rich model)

Read the entire page →

From page 6...

... 6• Peak period: period of at least 75 min during which is the space mean speed is less than 45 mph • Midday: 11:00 a.m.–2:00 p.m., Monday–Friday • Weekday: All day, Monday–Friday The team selected a natural logarithmic form for the regression model, because it is able to predict a TTI of 1 when the independent variables are 0. Root mean square error (RMSE)

Read the entire page →

From page 7...

... 7 collected on 26 freeway segments in the Seattle metropolitan area. Table 1.5 shows the validation error (the percentage difference between the measured and the predicted values)

Read the entire page →

From page 8...

... 8Table 1.5. L03 Validation Errors Roadway Section Peak Period Weekday Data-Poor Mean 80th 95th Mean 80th 95th 80th 95th I-405 Bellevue northbound +30 to 40% Over +40% Over +40% Under +10% +10 to 20% +10 to 20% Under +10% +20 to 30% I-405 Eastgate northbound +10 to 20% +10 to 20% +30 to 40% NA Under +10% Under +10% Under +10% +30 to 40% I-405 Eastgate southbound -10 to 20% -10 to 20% Under -10% -10 to 20% -10 to 20% -10 to 20% Under +10% -20 to 30% I-405 Kennydale southbound -10 to 20% -10 to 20% -10 to 20% -10 to 20% -30 to 40% -30 to 40% Under -10% -20 to 30% I-405 Kirkland northbound Under +10% Under +10% +20 to 30% Under +10% Under +10% +20 to 30% +10 to 20% +30 to 40% I-405 Kirkland southbound Under -10% Under +10% +10 to 20% Under -10% Under +10% +20 to 30% Under +10% +30 to 40% I-405 North northbound Under +10% Under +10% +20 to 30% Under +10% Under +10% +10 to 20% Under +10% +20 to 30% I-405 North southbound -30 to 40% Over -40% Over -40% Under +10% -10 to 20% -20 to 30% -10 to 20% Over -40% I-405 South northbound -30 to 40% -30 to 40% -20 to 30% -20 to 30% Over -40% Over -40% -10 to 20% -20 to 30% I-405 South southbound Under +10% Under +10% +10 to 20% +10 to 20% +20 to 30% +10 to 20% Under +10% +10 to 20% I-5 Everett northbound Under +10% Under -10% -10 to 20% Under +10% Under +10% -30 to 40% +20 to 30% Over -40% I-5 Everett southbound +20 to 30% +20 to 30% +30 to 40% Under +10% +10 to 20% +20 to 30% Under +10% Under +10% I-5 Lynnwood northbound +10 to 20% +20 to 30% Under -10% Under +10% Under +10% -10 to 20% Under +10% +20 to 30% I-5 Lynnwood southbound Under -10% Under -10% -10 to 20% Under -10% Under +10% -20 to 30% +10 to 20% -30 to 40% I-5 South northbound +10 to 20% +20 to 30% +30 to 40% Under +10% +10 to 20% Under +10% +10 to 20% +30 to 40% I-5 South southbound +10 to 20% Under +10% +20 to 30% Under +10% Under +10% +20 to 30% +10 to 20% +30 to 40% I-5 Tukwila northbound +20 to 30% +10 to 20% +10 to 20% Under +10% Under +10% Under +10% Under +10% +20 to 30% I-5 Tukwila southbound Over +40% Over +40% Over +40% Under +10% Under +10% +20 to 30% Under +10% Under +10% I-90 Bellevue westbound +20 to 30% +30 to 40% +30 to 40% Under +10% Under +10% +10 to 20% +10 to 20% +20 to 30% I-90 Bridge eastbound +10 to 20% Under +10% Under +10% Under +10% Under +10% +20 to 30% Under +10% +30 to 40% I-90 Bridge westbound Under -10% -10 to 20% -10 to 20% Under -10% Under +10% -10 to 20% +10 to 20% -10 to 20% I-90 Issaquah westbound +10 to 20% +10 to 20% +10 to 20% Under +10% Under +10% +10 to 20% Under +10% +20 to 30% SR 167 Auburn northbound Under -10% Under -10% Under +10% Under -10% -10 to 20% +20 to 30% Under -10% -20 to 30% SR 167 Auburn southbound -10 to 20% -20 to 30% -20 to 30% Under -10% -10 to 20% -30 to 40% Under +10% -20 to 30% SR 167 Renton northbound Under +10% +20 to 30% -10 to 20% Under +10% +10 to 20% -20 to 30% Under +10% +20 to 30% SR 167 Renton southbound Under +10% Under +10% -10 to 20% Under +10% Under +10% -10 to 20% Under +10% +20 to 30% Note: NA = not available.

Read the entire page →

From page 9...

... 9 • Appendix B: Validation Plan is a technical report outlining the data collection and analysis strategy for validating the L03 data-rich and data-poor models. • Appendix C: Data-Rich Validation is a technical memorandum containing detailed validation results for the data-rich models.

Read the entire page →

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