Metro’s Kate Model: 25,000 phantom cars a day on the I-5 bridge
By Joe Cortright
How can we trust Metro’s model to predict the future, when it can’t even match the present?
Metro’s Kate travel demand model, used to plan the $7.5 billion Interstate Bridge, includes 25,000 phantom cars per day in its base year estimates.
The existing I-5 bridges over the Columbia River carried 138,800 vehicles on an average weekday in 2019, according to ODOT’s official traffic count data.
But not according to Metro’s Kate traffic model: Kate claims the I-5 bridges carried 164,050 vehicles in 2019
The difference shows Metro’s model isn’t accurate: It can’t even replicate current conditions
And yet we’re expected to believe this same model can accurately predict traffic levels decades into the future?
This exaggeration is key to false claims about the severity of current and likely future traffic conditions, and is an illegal basis for the project’s federally required environmental analysis.
Metro’s Kate travel demand model claims 164,050 weekday vehicles in 2019
We obtained the outputs from the Metro travel demand model provided to the Interstate Bridge Project via a public records request. The following portion of the Excel spreadsheet shows the vehicle counts for the I-5 bridge according to the Metro model. This panel is from cells A1_B11 and cells F1:G11 in tab “summary” of a spreadsheet called “I5_xing_auto_truck_vol_comp_042922.xlsx” dated April 29, 2022. (The same data appears in February, 2023 versions of the output of the Metro model).
The abbreviations for vehicle type are single occupancy, multiple occupancy and heavy and medium trucks; the abbreviations for direction are Northbound and Southbound. These columns refer to the estimated 2019 No-Build (NB) forecast. The total volume of vehicles sums to 164,050.
ODOT’s Traffic Counter shows only 138,780 vehicles per day.
The Oregon Department of Transportation maintains a series of automatic traffic data recorders that count the number of vehicles that use state highways. Recorder number 26-004 measures traffic on the Interstate Bridge. The following table, taken from the ODOT website, shows the average weekday traffic for each month in 2019. The annual average (sum of monthly average traffic divided by twelve months) is 138,780 vehicles per day.
The difference: more than 25,000 phantom cars per day.
Metro’s travel demand model claims the I-5 bridges are carrying 25,000 more vehicles per day than ODOT is actually counting. This is a huge error: Metro’s model over-states traffic volumes in the current year by more than 18 percent.
In essence, the EIS, which is supposed to be based on fact, is full of false claims about actual traffic levels on I-5. This is a plain violation of the National Environmental Policy Act, which requires that data be accurate and scientifically sound (40 CFR § 1502.23).
Metro’s Kate Model: 25,000 phantom cars a day on the I-5 bridge
How can we trust Metro’s model to predict the future, when it can’t even match the present?
Metro’s Kate travel demand model, used to plan the $7.5 billion Interstate Bridge, includes 25,000 phantom cars per day in its base year estimates.
The existing I-5 bridges over the Columbia River carried 138,800 vehicles on an average weekday in 2019, according to ODOT’s official traffic count data.
But not according to Metro’s Kate traffic model: Kate claims the I-5 bridges carried 164,050 vehicles in 2019
The difference shows Metro’s model isn’t accurate: It can’t even replicate current conditions
And yet we’re expected to believe this same model can accurately predict traffic levels decades into the future?
This exaggeration is key to false claims about the severity of current and likely future traffic conditions, and is an illegal basis for the project’s federally required environmental analysis.
Metro’s Kate travel demand model claims 164,050 weekday vehicles in 2019
We obtained the outputs from the Metro travel demand model provided to the Interstate Bridge Project via a public records request. The following portion of the Excel spreadsheet shows the vehicle counts for the I-5 bridge according to the Metro model. This panel is from cells A1_B11 and cells F1:G11 in tab “summary” of a spreadsheet called “I5_xing_auto_truck_vol_comp_042922.xlsx” dated April 29, 2022. (The same data appears in February, 2023 versions of the output of the Metro model).
The abbreviations for vehicle type are single occupancy, multiple occupancy and heavy and medium trucks; the abbreviations for direction are Northbound and Southbound. These columns refer to the estimated 2019 No-Build (NB) forecast. The total volume of vehicles sums to 164,050.
ODOT’s Traffic Counter shows only 138,780 vehicles per day.
The Oregon Department of Transportation maintains a series of automatic traffic data recorders that count the number of vehicles that use state highways. Recorder number 26-004 measures traffic on the Interstate Bridge. The following table, taken from the ODOT website, shows the average weekday traffic for each month in 2019. The annual average (sum of monthly average traffic divided by twelve months) is 138,780 vehicles per day.
The difference: more than 25,000 phantom cars per day.
Metro’s travel demand model claims the I-5 bridges are carrying 25,000 more vehicles per day than ODOT is actually counting. This is a huge error: Metro’s model over-states traffic volumes in the current year by more than 18 percent.
In essence, the EIS, which is supposed to be based on fact, is full of false claims about actual traffic levels on I-5. This is a plain violation of the National Environmental Policy Act, which requires that data be accurate and scientifically sound (40 CFR § 1502.23).
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