Washington DOT Tacoma Narrow Bridge


  • Assure-ITTM Implementation for Tacoma Narrow Bridge Project
  • Client: Washington State Department of Transportation
  • Location: Tacoma, WA
  • Project Value: $849M Design-Build Tacoma Narrows Bridge

Project Description

ATSER was selected by the Washington Department of Transportation (WSDOT) to provide professional quality management services and systems in support of the Tacoma Narrows Bridge Project in Tacoma, Washington. This $849 million project added a second suspended tolled bridge crossing over the Tacoma Narrows waterway located 30 miles southwest of Seattle.

Client's Challenge

The Tacoma Narrows Bridge, originally designed in the 1950s to handle 60,000 cars per day, was handling over 90,000 cars per day by 2002 when the project to build a new bridge adjacent to it was begun. (The older Tacoma Narrows Bridge replaced a bridge that was destroyed in a 1940 windstorm. The collapse of the first bridge was captured on film and ultimately changed the way suspension bridges were designed.) Major construction work on the new bridge included building a pair of 165-meter-tall towers, spinning cables, and assembling the 46 deck sections that comprise the bridge decking. The entire deck stretches 1,646 meters with the main span stretching 854 meters from tower to tower.

The new suspension bridge was built parallel to and south of the existing bridge, providing two general-purpose lanes and a high occupancy vehicle lane for eastbound traffic. The new bridge included a separated path for bicycles and pedestrians. It was also designed to accommodate a second deck in the future. As part of the overall project the existing bridge was reconfigured to provide two general-purpose lanes and a high occupancy vehicle lane for westbound traffic only. The existing bridgework also included seismic improvements. In addition to the bridge works, the project also constructed 3.4 miles of SR 16 from the Jackson Avenue interchange in Tacoma to a new interchange at 24th and 36th Streets.

The construction contractor needed a cost effective way to manage the numerous Quality Assurance tests associated with this initiative throughout the program life cycle. Complicating the challenge is the increased speed expected in this design-build project. This “need for speed” is particularly important in the Quality Assurance process as field samples must be collected, analyzed, and statistically verified and reported as quickly as possible so as not to impede the orderly progress of work at the field construction site.

ATSER's Solution

ATSER was tasked to prepare a Quality Assurance Procedure for Construction (QAPC) that spelled out the roles and responsibilities of all parties for all aspects of construction quality. The QAPC provided the procedural basis for tracking material and workmanship quality by both WSDOT and the design-build team.

Complementing the QAPC, ATSER implemented a customized version of its flagship web-based quality management system: Assure-IT. This system provided a universal, consistent backbone for the capture, reporting and analysis of all relevant quality data from either the testing laboratories or directly from the field. Handheld computers, pre-programmed with test forms and inspection checklists, provided the electronic link between the field and the central database. Success in the implementation of Assure-IT resulted from close cooperation between WSDOT and Tacoma Narrows Constructors, a design-build joint venture.


ATSER successfully deployed Assure-IT and the new Tacoma Narrows Bridge opened in July 2007, on schedule and on budget. This project illustrates ATSER’s ability to customize, configure, deploy and migrate to one centralized database the information needed to assure quality and analyze data to spot trends at a complex construction program.