Pioneers in Asphaltic & Unbound Materials Testing

About us

James (Jim) Cox initially worked as a design engineer developing products to test asphalt for highway construction. Jim started out working for the Californian highway materials and research division. Jim left to set up his own business, originally working from his garage in Sacramento. Later Jim set up “James Cox & Sons” based in Colfax, California, a professional business that is globally renowned for innovation and quality. The business has been successfully trading for over 30 years. Cox & Sons was selected by The University of California at Berkeley (UCB) to design and manufacture the prototype shear testing system for the federal Strategic Highway Research Program (SHRP). SHRP was initiated to develop standards for road construction in this country. The original testing system is still in use at the Richmond Field Station (UCB). Over the years, James Cox & Sons has developed a line of products for asphalt, concrete and soil testing which conform to various ASTM, AASHTO and Californian specifications. Cox & Sons has built a reputation for manufacturing the highest quality equipment utilizing the finest materials and latest technology. We integrate all of these factors to provide top-of-the-line systems for a complete customer orientated solution. All of our products are designed and fabricated with care and precision in the heart of Gold Country, Northern California. We are proud to say our products are Made in America.

Cox & Sons – Cooper Research Technology

One Company – with a focus on Quality, Innovation, Value

James Cox & Sons, based in California, is a manufacturer of Superpave Equipment that is renowned for its quality & technology. Sharing a vision with its parent company, Cooper Research Technology, they combine over 50 years experience in Asphalt Testing Technology and Innovation. 

Cooper Research Technology is a British company globally recognised as the leading innovator in the design and manufacture of high performance testing equipment for asphalt and unbound materials used in highway construction. 

Both Cox and Cooper have been at the forefront of academic research – Cox’s close links with UCB and Cooper in collaboration with Nottingham University (NTEC), and our commitment to be at the forefront of academic research continues. 

The combined business, together with a strong focus on customer orientated solutions, respected industry knowledge and technical expertise, and the highest levels of quality manufacturing, support our objective to continue to deliver unsurpassed innovation, quality and value. 


The NEW cDAC industry-leading control technology, based on over 50 years combined development experience. Precision control technology is essential to achieving accurate results. With over 50 years combined experience working closely within the civil engineering research community, Cox & Sons provides digital control technology that is unparalleled for its flexibility, scalability and simplicity of operation. No matter what your testing requirements, Cox & Sons offers the perfect control system to meet your every need. Our newly developed control system cDAC and universal software “DIMENSION” is the most advanced system available on the market today. The cDAC controller is a state-of-the-art, fully digital servo hydraulic controller that utilizes National InstrumentsTM RIO hardware and LabviewTM software. It is capable of running the most demanding static and dynamic tests. Fully digitalised with user defined arbitrary wave settings
as standard. No system offers as many input or output channels, using a fully automated input recognition system that pre-loads appropriate drivers and relevant calibration factors (TEDS –Transducer Electronic Data Sheet). True Universal Software with pre-loaded standard test database and a report writer function. The TDMS data output format provides far more information for the user and is fully compatible with Excel® and other Microsoft® software. NI Reconfigurable I/O (RIO) hardware and NI LabVIEWTM software provide the best platform to solve any demanding control and monitoring task. If you have a specific software requirement, the answer is YES our system can do it.


Our consultative approach ensures that your application is fully understood before an order is accepted, thus ensuring that the equipment ordered is fit for purpose and will deliver the expected results reliably, day after day and year after year. Our comprehensive design team covers various engineering disciplines; mechanical, electrical, electronic, pneumatic and hydraulic, coupled with a specialist software department, ensuring that everything gels together and functions as you would wish. Our products are tailored to suit your needs. Supplying the research, DOT’s and commercial sectors means innovation and invention. Innovation and invention is our provenance, work with us, you will enjoy the experience.