Today the Just Crossing Alliance (JCA) released an independent assessment of IBR traffic modeling conducted by Norman Marshall, president of Smart Mobility. Mr. Marshall specializes in analyzing the relationships between the built environment and travel behavior and doing planning that coordinates multi-modal transportation with land use and community needs.
A key finding of the report is that the Draft Supplement Environmental Impact Statement (DSEIS) forecasts more traffic in the corridor in the no-build scenario than is physically possible (a similar error in the CRC EIS has been confirmed by historical data). JCA members reacted to the information noting that if the no-build forecast is invalid, then all the environmental analysis in the DSEIS is without basis!
Other conclusions of the Marshall report:
- The Interstate bridge is not the I-5 bottleneck in either direction
- Congestion to the south “meters” traffic on the bridge during peak periods, and traffic cannot grow without road expansion to the south
- Metro’s regional Kate model relied on in the DSEIS significantly overestimates peak period traffic today and forecasts impossible traffic growth in the future
- This impossible traffic growth forecast is the basis for the DSEIS traffic metrics, i.e., garbage in – garbage out
- Higher speed AND higher throughput are possible without expansion through better ramp metering, and/or system-wide tolling