I-5 Expansion and Remodeling Analysis: City of Seattle CEE498 GIS Final Project Matt Elliott Tina Jang Justin Hughes Karina Pineda Amber Yamamoto

Project Overview Objectives Objectives Area of Study Area of Study Data Collection Data Collection Considerations Considerations Data Analysis Data Analysis Conclusion Conclusion

Objectives Improving system performance Improving system performance  Decrease traffic congestion  Increase safety in accident prone areas

Area of Study I-5 corridor from milepost 162 to milepost 178

Data Collection Digital orthophoto of area Digital orthophoto of area Roads Roads Wetlands Wetlands Bridges Bridges Milepost Markers Milepost Markers Infrastructure Infrastructure Accident Rates Accident Rates Traffic Flow Rates Traffic Flow Rates Right of Way Right of Way Attenuators Attenuators Guardrails Guardrails Cross Culverts Cross Culverts

Considerations Need based: Areas prone to traffic congestion and accidents Areas prone to traffic congestion and accidents Cost based: Environmental impact on wetlands Environmental impact on wetlands City right of way City right of way Cost of construction Cost of construction Existing Infrastructure Existing Infrastructure

Need-Based Analysis Need analysis was based on the need for lane widening and reconstruction of ramps. A ranking of 1 thru 4 (based on severity) was done for congestion for AM peak and PM peak, accidents, and injuries resulting from accidents. These rankings were then summed in order to find the total need as seen in the map.

Cost-Based Analysis Cost analysis was based on the cost of construction, considering existing infrastructure. A ranking of 1 thru 4 (based on number of units in a given segment) was done for parcels within 150 ft of I-5, buildings within 170 ft, as well as wetlands and bridges intersecting the freeway segments. These rankings were then summed in order to find the total ranked cost as seen in the map.

Calculated Values

Rating System

Conclusion I-5 near Northgate is one area identified as needing improvements. The relatively low-cost ranking for this section of freeway makes it a cost-effective area for improvement. Reconstruction or widening of the ramps in this area can improve system performance by decreasing traffic congestion while increasing safety.

Resources atacatalog/default.htm atacatalog/default.htm Puget Sound Traffic – Congestion Map Archive, Puget Sound Traffic – Congestion Map Archive, Heather Rein, of WSDOT Heather Rein, of WSDOT