Central Avenue Improvements

Client—City of Tenino, Washington

Gibbs & Olson provided land surveying, planning, design and construction phase engineering services. Gibbs & Olson evaluated the combination of existing pavement and subgrade to determine what portions of the project required complete replacement and what areas were in acceptable condition for an overlay, minimizing project costs. The design improved traffic flow and pedestrian crossing safety by increasing the on-street bus loading parking and travel lane width in front of Parkside Elementary School. Additional safety measures included providing a paved shoulder with defined parking patterns. Design elements included the widening and overlay of 1,800 feet of roadway (including curbs, gutters and sidewalks) and 1,900 feet of new 8 inch water main. Stormwater runoff was addressed using a series of infiltration galleries along the road corridor. Each gallery included individual pretreatment devices prior to infiltration. These pretreatment devices allowed for infiltration of stormwater within the limited space available. To maximize funding, the project was divided into a base bid plus five alternative schedules. These alternatives allowed the City to choose any combination of bid schedules without compromising the overall aesthetics and functionality of the design.