Item C: I-5 Franklin Proposed Interchange Project Update

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MEMORANDUM DateOctober 14, 2005 Project : #: 7068 To: Sam Seskin and Tim Burkhardt, CH2M Hill From: Julia Kuhn and Lani Tribbett Project: I-5/Willamette River Crossing Subject: Traffic Forecasts – Task 5 As part of Task 5 activities on the I-5/Willamette River Crossing project, we have prepared the following memorandum to summarize our analysis of projected traffic volumes for four potential interchange configurations at Franklin Boulevard. The interchange alternatives evaluated include: Category #1: Creation of a fully directional I-5 interchange at Franklin Boulevard. This could occur as a full diamond or cloverleaf configuration. Category #2: Modification of the existing Franklin Boulevard to provide ramps to/from the north on I-5. Our analyses assumed that the new southbound off-ramp and northbound on-ramp would provide access to Franklin both eastbound and westbound. The existing ramps to/from the south at this location would remain in their current configuration (i.e., access to the west only). Category #3: Reconstruction of the Franklin and Glenwood interchanges to create two partial interchanges. The Franklin interchange would provide access to/from the north and the Glenwood interchange would provide access to/from the south. The two partial interchanges could be connected through the use of (A) the existing street system (i.e., Glenwood Boulevard and Franklin Boulevard) or (B) via frontage roads along I-5. Each of these scenarios was compared to a 2025 “no build” condition. This “no build” condition assumes that the existing ramp configurations remain in-place but other system improvements on the fiscally constrained Regional Transportation Plan list are constructed. The categories of interchange concepts are graphically depicted in the Task 4 memorandum prepared by CH2M Hill and Kittelson & Associates, Inc. under separate cover. The Task 4 memorandum also discusses a fourth category of improvements that include the upgrade of the Glenwood interchange to a conventional diamond. From a traffic modeling perspective, this would not substantively change the traffic forecasts at this location because all FILENAME: E:\ODOT\332511\05 Traffic Analysis\Traffic Analysis.doc