Heffron Transportation led analysis for the consideration of a new on-ramp during the design-build phase of the Tacoma Narrows Bridge project. The new on-ramp enters State Route 16 (SR 16) just prior to the new bridge. It is an electronic-toll-collection-only ramp because it enters SR 16 after the electronic toll collection and after the manual toll collection booths. Analysis was prepared to address changes in weaving and merging conditions on the SR 16 mainline with various scenarios of electronic versus manual toll collection rates. The timely technical analysis was developed to support rapid decision-making regarding design issues for the on-ramp and auxiliary lane. The firm also prepared the Transportation Discipline Report to support the required environmental review documentation (SEPA Addendum and NEPA Re-evaluation).