Up & Coming Changes to Hot Mix Asphalt (HMA)

Major changes are on the horizon for hot mix asphalt (HMA) specifications, as Caltrans plans to reinstate statistical pay factors (SPF) – a quality control method used back in the 90s to the mid-2010s. This re-implementation means that contractors and producers must, again, take full responsibility for quality control inspection, sampling, and testing of hot mix asphalt (HMA) on state highway projects over 2,250 tons.

There are certain implications to this return to Caltrans’ SPF program, including incentives and disincentives attached to the consistency of HMA production and placement.

For contractors/producers who consistently produce HMA that’s close to mix design targets at the plant and compaction requirements in the field, the future is bright – but inconsistent HMA production and field compaction will lead to lessened credibility, project delays, and a negative impact on your bottom line.

G3 Quality is a trusted source of information for contractors and producers across the state, and we’re here to guide you through this return to statistical pay factor (SPF) projects. Some contractors/producers may not be familiar with SPF specifications, but here at G3 Quality, it’s a return to normal. With our intimate knowledge of Caltrans’ requirements, a team of mix design specialists, and full service HMA testing laboratories throughout the state, we can act as both a guide and service provider – ensuring quality mix designs and reliable testing paving the way for successful projects.

Learn more about these up and coming changes to hot mix asphalt, and fill out a contact form if you have any questions related to QC/QA requirements and specifications.

The Return of Statistical Pay Factor Projects

For contractors and producers in the HMA business, a big change lies ahead that may feel like déjà vu. Caltrans will soon bring back the incentive and disincentive specification, formally known as QC/QA, rebranded as the statistical pay factor (SPF) specification – a familiar specification that many of us remember.

The QC/QA program provides incentives and disincentives to contractors based on a statistical analysis of your quality control data. Consistency in your HMA production means getting paid for the asphalt, plus a nice bonus. But inconsistent HMA production could end up hurting you financially, causing you to lose money on projects, project delays, or even face rejections.

Like the old QC/QA specifications, the new SPF specifications have three main goals. First, the SPF specifications will improve the quality of materials and processes used in highway construction projects and reduce the life-cycle costs. Second, the SPF specification will place responsibility for quality control on the contractor. Third, the SPF specification will reduce testing disputes between contractors and Caltrans.


“With the HMA statistical pay factors (SPF) specification, it’s crucial that contractors and producers tighten up quality control practices, produce consistent mixes, and properly place HMA. Those who can do all three, will surely benefit and have successful projects.”

 Matthew Ramos, Internal Quality Director, G3 Quality


Preparing for the Change

Knowing that SPF specifications, contractors and producers should start preparing now to smoothly adapt to the change:

  • Review prior QC/QA specs to understand requirements for statistical pay incentives, disincentives, quality control, and mix consistency
  • Examine your current hot mix asphalt quality control processes, make any necessary changes to ensure consistency, and tighten up your mix production
  • Train staff, especially new hires, on SPF principles and the importance of meeting specifications
  • Identify potential problem areas where mixes could lack consistency, and take corrective action
  • Build open communication between your estimators, project team, and quality control team to quickly address issues

With some advanced preparation, contractors can shorten the learning curve of the SPF specification – and we’re here to help with that process. For those less familiar with SPF specifications, G3 Quality is available to answer any questions you may have so that your team delivers consistent, quality HMA and maximizes profits on Caltrans SPF projects.

G3 Quality: How We Can Help

With over a decade of experience developing HMA designs and providing quality control testing and inspection, G3 Quality is a trusted guide for contractors and producers during this time of change. When you partner with us, you gain the guarantee that we will provide you with quality mix designs and provide experienced and qualified staff to ensure success on SPF projects. Our material testing laboratory has the equipment and qualified staff to carry out these tests, while our HMA technical staff will educate you on how to best comply with Caltrans’ SPF specifications.

Fill out a form on our Contact page to connect with our team, ask any questions related to upcoming HMA changes, and ultimately prepare your business for success on statistical pay factor projects.