Agenda - Council Work Session - 10/12/2021

Home

September 11, 2021 Page 89 Traffic Forecast & Analysis • Congestion is expected to increase on northwest metro highways under year 2040 no -build conditions. • Concepts 1 and 2 draw traffic from local roadways onto Highway 10, 101, and 610. These concepts do not significantly change traffic volumes on the Highway 169 river crossing. • Concept 3 draws 25,000 vpd to a new river crossing and reduces traffic volumes on Highways 101 and 169 by 8,000 and 10,000 vpd, respectively. Concept 4 draws 30,000 vpd and reduces traffic volumes on Highways 101 and 169 by 9,000 and 13,000 vpd, respectively. • Concepts 1 and 2 reduce V/C ratios on improved facilitates but have little impact on the Highway 169 river crossing. Concepts 3 and 4 reduce V/C ratios on Highways 169 and 610 relative to no - build conditions. • A 2040 traffic sensitivity test that increased telecommuting rates found that Highway 610 would be under capacity between Highways 169 and 252 in an increased telecommute scenario. I-94 and Highways 10, 101, and 169 are expected to continue to be congested under both traditional and telecommute forecasts. Benefit -Cost Analysis • The four concepts developed in this study provide regional travel time savings through decreased VHT. Concept 4 provides the most travel time savings among the concepts evaluated. • All four concepts have a B/C ratio of at least 1.0 under scenarios with traditional travel behavior assumptions. Each concept retains a B/C ratio greater than 1.0 under a sensitivity test that considers increased telecommuting. Operational Analysis • The four concepts developed in this study result in significant operational benefits for the I- 94/Highway 101 interchange. Concept 2 (southbound Hwy 101 to eastbound I-94 flyover ramp) achieves the most benefits, but Concept 1 (conversion to a diverging diamond interchange) is more cost effective. • A new river crossing following the Zanzibar/Armstrong alignment reduces delay at the I- 94/Highway 101 interchange by diverting traffic away from Highway 101. This results in a greater than 50 percent reduction in AM peak hour delay. • A new river crossing following the Zanzibar/Armstrong alignment results in a 50 percent reduction in year 2040 congestion duration at the Highway 169 river crossing, from 10 hours per weekday under the year 2040 no build scenario to five hours per weekday under the Concept 3/4 build scenario. • A new river crossing following the Zanzibar/Armstrong alignment increases delay at the I-94/ Dayton Parkway and the Hwy 10/Armstrong Boulevard interchanges. Relatively small-scale geometric improvements are available to mitigate these increases, allowing these interchanges to continue to operate acceptably with a new river crossing connection. • Traffic sensitivity analysis reached the following conclusions: o The operational benefits of Concepts 1-4 at the I-94/Highway 101 interchange are similar under traditional and increased telecommuting forecasts. o The I-94/Dayton Parkway interchange operates acceptably in the telecommute no -build and Concept 3/4 build scenarios. Northwest Metro Mississippi River Crossing Feasibility Analysis