The removal and replacement of a portion of the SR 16 off-ramp is unfortunate and embarrassing for the WSDOT. This mistake is not indicative of the high quality design work produced by our engineers, as evidenced by the many successful construction projects throughout the state.
The entire Nalley Valley interchange was funded in three phases - westbound, eastbound, and HOV connectors - and the current westbound project was designed over the course of several years by numerous WSDOT and consultant engineers.
This phasing clearly required a great deal of coordination between the design teams to ensure the designs meshed together. The error lies in the compatibility of the SR 16 off-ramp to Sprague Avenue with the build-out of the second phase (eastbound project) that started in 2011.
Specifically, the addition of a third lane to the eastbound project was not communicated or coordinated with the current westbound project and the ramp needs to be lowered to provide additional lateral clearance for the added lane.
When did WSDOT know the ramp wasn't going to work?
This error was realized only after ramp construction was 90 percent complete. It was while the crews were staking the location for the impact attenuator that they noticed there was a grade differential where the “gore” between the off-ramp and the traffic lane of eastbound SR 16 should have been flat. This occurred in late 2009 and work was at that point halted pending an in-depth investigation and resolution. The cause of this error was traced back to the design of the off-ramp, which was based on the previous two-lane roadway and not the newly designed three-lane eastbound SR 16.
Why didn't WSDOT release information about the ramp mistake?
This error and the resulting construction was brought forward to management at WSDOT and also discussed at a Quarterly Project Review (QPR) meeting held in December, 2009. The QPR reporting this error was loaded on the project page for this project following the December Quarterly Program Review: http://www.wsdot.wa.gov/Projects/PierceCountyHOV/SR16_WBNalleyValley/QPR/Dec2009.htm.
After reporting and posting this error on the Quarterly Project Report on the project Web page, we did not conduct our accustomed contacts with the Legislature or public. Although WSDOT's practice is to actively report on projects through Quarterly Program Review, we have in the past used telephone calls to legislative leaders and issued media releases when sharing noteworthy issues.
Unfortunately, no legislative contacts or press releases were issued about this error or the necessary fix resulting from the error. In late June 2010, media began to ask questions about this work, and WSDOT responded immediately with details and references to the Quarterly Project Report on the website.
How did WSDOT fix the ramp?
After determining the cause of the error, engineers looked at several approaches to fix this error. Alternatives included complete removal and replacement of the ramp, partial removal and changes to the profile, and re-channelizing the necessary lanes within the current geometric configuration.
Ultimately the fix selected was the partial ramp removal and profile change along 700 feet of the ramp.
How much did the fix cost?
This additional work was added to the current contract by change order for $889,958.
Is that the entire cost?
The $890,000 is the ramp reconstruction cost - the change order cost - and did not include WSDOT’s labor costs to troubleshoot, redesign, and ultimately issue new construction documents. From an accounting standpoint, our labor budget and expenditures are always tracked separately from construction costs.
WSDOT’s labor costs associated with the reconstruction effort are listed below. It is important to note that most of the staff time spent on the reconstruction effort was by staff already working on the construction of the Nalley Valley project, so their time was already budgeted and planned to be billed to the project. Having the expertise on the project avoided the need to bring in additional resources from our HOV design office, which reduced the overall engineering cost to the project.
Evaluation of the problem:
The WSDOT HOV Design Office provided the initial troubleshooting and analysis to determine if the ramp as constructed could be salvaged. Those costs amounted to approximately $10,400. The Construction Office staff contributed to this effort at a cost of about $500.
Redesign and construction documents:
HOV Design Office and the Construction Office staff spent approximately $3,600 and $20,700, respectively to redesign the ramp.
Negotiating and administering the change order:
This was primarily a management function, with an estimated cost of $1,400
Surveying is performed by WSDOT’s contractor on this project and was included in the change order cost.
Repaving, demolition, and disposal:
These items of work are performed by the contractor and are included in the change order. WSDOT’s estimated inspection cost for reconstruction work is $9,000.
Legal costs: None.
To summarize, WSDOT labor costs associated with the reconstruction of the ramp were approximately $45,600.
Who was responsible for the mistake?
Since this was an error in the plans, WSDOT is responsible for the fix and not the contractor.
When did the work to fix the ramp begin?
The change order for this work was executed June 21, 2010.Work started by removing the new concrete pavement. Crews then excavated the embankment between the walls and removed selected panels of the retaining wall. The maximum grade change in this fix was approximately 12 feet. After the ramp was lowered to the revised elevation, it was repaved.
How long did it take to complete the ramp?
This work took approximately 12 weeks to complete and did not affect traffic.
What did this error do to the project schedule?
This work did not delay completion of the Westbound Project. This work was accomplished within the existing working days without affecting other work. No time extension was granted to the contractor with this change order.
How did this affect the project budget?
The rework necessary to fix this error cost $889,958 and came from the current project budget. While this was an unforeseen expense, it was accounted for in the project contingencies that are set up on construction projects.
Contingencies on this project were estimated at 5 percent and amounted to $6.7 million.
In addition to the contingency funds set up on this project there was a Risk Matrix established, modeled from the CEVP process, which amounted to $8.49 million. That said, we did not take this issue lightly.
How did WSDOT ensure this won't happen again?
As a direct result of this error, WSDOT implemented several new steps in an effort to prevent errors like this before they become part of the contract plans. WSDOT will continue to monitor progress on the development of future HOV projects and adjust the practice as necessary. Steps include:
- Use of a third party (non-HOV design staff) to review all plans for approval and profiles for the entire Nalley Valley Interchange Design
- Revised design procedures within the HOV program to specifically perform quality checks at the beginning and ending of tie-in points
- HOV Construction Support Team performs a robust review of all project, scope and engineering (PS&E) packages prior to advertisement for bids.
- Revised the Quality Review Comments Form to require all design review comments to be resolved prior to completion of PS&E packages
- On a statewide basis, ensure our contacts for issues are reinforced to eliminate occurrences such as this in the future.