Evaluating the benefits of accelerated pavement testing

Abstract

South Africa, like many other countries, is facing challenges regarding the optimal utilisation of taxpayers’ money to the benefit of the country. Research, transportation infrastructure research in particular, has its unique challenges as it competes with very sensitive public spending needs such as health, education and safety. Very often research does not receive its rightful share in government’s investment in public services. The downstream effects of neglecting the upkeep and maintenance of our road infrastructure is rising logistics costs and social disbenefits due to a lack of acceptable access to facilities such as hospitals, schools and shops. Due to the pressure on the available funding for research, it is increasingly more important to justify research spending and the success of continued governmental support depends on the impact of the research. The development of the first South African electric passenger vehicle, the Joule, is an example of a product that was never commercially available and investment in its development was ceased in 2012. Research utilising Accelerated Pavement Testing (APT) machines are expensive in comparison with mere laboratory testing. However, they are reliable tools to assess the durability of full-scale road structures in a short period of time and to avoid costly early failures. The ability to measure the impact of implementable research stemming from APT-related research is becoming more important given the backdrop above. This thesis is centred around the development of a robust methodology to measure the success and impact of research from a particular type of APT device, the South African designed Heavy Vehicle Simulator (HVS). Research with the HVS started in the 1960s and is still continuing in South Africa and in many other countries. With the use of well-established tools and models the author developed a methodology to measure the impact and benefits of APT. This methodology was tested on a case study of a sizable pavement rehabilitation project in California. Realistic and defendable results were derived and were within industry acceptable norms. It is also realised that the quantification of benefits through the deterministic analyses done in this thesis is narrative and does not capture the true value of implemented research. Non-quantifiable, qualitative, indirect or downstream benefits should also be recognised for their positive societal contribution. It must be stressed that, although the methodology developed as described in this thesis mainly focused on benefit determination of APT-related research in California, it is generic by nature and can easily be adopted in South Africa across various spheres of research impact measurement.