The third article in our series on the roading big picture focuses on a NZ Transport Agency commissioned report on big project pavement quality. By ALAN TITCHALL.
LAST YEAR the New Zealand Transport Agency commissioned Chris Olsen Consulting to prepare a report on pavement quality on its state highway network projects.
The findings were delivered in a 26-page document called ‘Collecting Information on the Pavement Quality Of Construction Projects’, and presented to the Transport Agency in November 2015.
It was thought that the report might have been discussed at the Transport Agency/NZIHT roading conference at Waitangi late last year. However, the agency needed to consider the recommendations under its ‘Quality Right, No Defects’ project, so we are now able to provide our readers with some of the report’s highlights and we thank both the Transport Agency and Chris Olsen for this opportunity.
“The Transport Agency should be commended for commissioning this report to look at how it can further improve the construction quality of its large projects,” says Chris.
Driving the commission was a concern that pavement quality was “not adequate in all cases”. The Transport Agency wanted to know why pavement quality was variable around some projects and “identify possible improvements in the pavement quality of construction projects”.
People within the Transport Agency, consultants (the agency’s principal advisors) and 19 contracting ‘practitioners’ across four case studies, were interviewed. All consultants and contractors involved had won large state roading contracts through a tender selection process (including non-price attributes), and had substantial work experience on a large construction project. Using an interview process and 58 questions, a ‘panel of experts’ solicited around 1100 responses and views on pavement quality from these participants. Both the questionnaire and a resulting draft report were reviewed and verified by the NZTA, ACENZ and CCNZ.
The Transport Agency gave an assurance that all the information collected during the research would only be used for ‘continuous improvement’ and not for the resolution of any contractual issues.
“This was important for ensuring that the real issues were highlighted and it’s great to see that this has resulted in positive changes in the way the Transport Agency deals with contracts,” says Chris.
This was evident when the ‘Huntly’ Design and Construct (build) contract was announced last year with its prescriptive approach to pavement quality.
The average rating over all contracts concerned (with the smallest being a $30 million project and the oldest 10 years) for achieving the required pavement quality rated at 4.9 out of 10.
The general performance of the Design and Construct (D&C) contract sample projects proved a “serious concern”.
The one Alliance contract case study produced better pavements, even though it had only one KPI. This was because of its inherent “best for project” Key Result Areas (KRA), which meant all parties ensured any problems with the Principal’s Requirements and KPIs were resolved.
While parties involved with the D&C contracts rated their performance of achieving the project’s Principal Requirements as an average of 8 out of 10 and rated the achievement of their definition of quality at an average of 5.9 out of 10 – the quality of the finished product was significantly lower. In comparison, the Alliance contract scored between 8 and 9.5 out of 10 on all three ratings.
“The D&C contracts struggled to produce quality pavements because the combination of less than optimum KPIs and a competitive market consistently produced thin, high risk, low cost pavements that sometimes appeared to compromise future lowest whole-of-life maintenance costs, coupled with a reluctance of project teams to make changes,” notes the report.
Contract management and relationships scored highly across the contract parties with the exception of one project.
“In hindsight, to avoid such situations arising again, the Transport Agency’s pavement experts should be brought into the project team to help it address the issues and clear protocols developed for improved communication between the Pavement Team and the contract parties,” the report recommended.
While parties were generally aligned at the start of a contract in terms of quality management systems they “nearly always became misaligned during the project because of the contractor and the Transport Agency’s Pavement Team having different interpretations of KPIs”.
The report recognised the differences and benefits between the two contract styles, such as continual improvement through an Alliance project and the opportunity of pushing innovation in a D&C contract, although it found in its sample case studies little innovation and mostly cost cutting. Overall, innovation was rated at only 5.9 out of 10. Contractors were rated at 7.6 out of 10 for making submissions to support innovative proposals, but all parties rated the agency’s processes for approving changes to enhance innovation at only 3.6 out of 10.
The report also found issues with the contracting sector. There was a direct correlation between poor pavement construction quality and no third party management, surveillance and quality assurance (MSQA) review of the contractor’s quality management systems.
The report advised the Transport Agency to adopt a number of processes for improving pavement quality in construction projects.
They included: Setting adequate Principal Requirements commensurate with an appropriate contract model. For D&C contracts this could mean further developing the KPIs, specifying minimum requirements or requiring long-term performance warrantees.
- To consider Net Present Value for whole-of-life pavement maintenance costs when awarding tenders.
- Make an effort to improve alignment between the agency and contractor around ongoing design expectations and the design Quality Management System.
- Provide clear contractual requirements, incentives and penalties around expected pavement life.
- Make sure design criteria and assumptions are verified during construction by the client and changed if necessary.
- Develop clear contractual communications protocols and expected communication behaviour for Project Teams and the Transport Agency’s Pavements Team when interacting with contractual parties.
- Make sure specified pavement life expectations and funding objectives are clearly and transparently aligned before awarding tenders.
- Verify the onsite application of the contractor’s Quality Management System through a clarification of the MSQA consultant’s role.
- Develop a Quality Management System like RAMM that collects “as laid” data (because utilities have had difficulty in accessing this information).
- Develop a quality system that covers Pre-tender, Tender, Pre-award, Design Development, Construction, Post-Construction, and “as laid” records, to ensure consistency across the agency’s staff and regions.
- Develop a process for improving the understanding of modified pavements, and sharing the lessons from this, especially with the agency’s project managers and MSQA consultants, because modified pavement performance is critical in meeting the KPIs, but is generally uncharted water with many professionals having different views.
- Develop a process for making “best for project” pavement type decisions because of the many different individual professional views.
- Have detailed quality plans available for the client prior to the start of construction and develop an audit process in collaboration with the contractor and consultant. “This will include third party sampling and testing and review of all quality records and ongoing work to ensure it is completed in line with the quality plans and design assumptions.”
Comments from the participants
An interesting part of the report is a summary of responses made in the ‘any other comments’ section of the questionnaire. They included:
- “Design theory and construction don’t always match.”
- “Nowhere in Austroads standards are there deflection subgrade strain requirements, so it is unconventional to use them because they are largely unproven. (Yet the basis of our design is subgrade strain.)”
- “Sometimes instead of solving design problems, designers take the easy way and simply raise the bar.”
- “Systemic failure in using granular pavements with chip seals on major roads, as the pavements can’t handle the ESA (rutting) and the high traffic volumes reduce the amount of bitumen making the chip seal un-waterproof.”
- “Traffic volumes are now in excess of those that a granular pavement can handle – why use granular pavements for D&C?”
- And this wee gem: “At the end of the day you get what you pay for.”