New Methods For Network Level Automated Assessment Of Surface Condition In The UK

Automated traffic-speed surveys have been applied on the English Strategic Road Network since 2000, under the Traffic-speed Condition Surveys (TRACS) specification, which employ image and laser-based equipment to measure surface condition at traffic speed. The original requirements for TRACS surveys were based on research carried out by TRL for the Highways Agency. However, there have been significant advances in the technologies for the measurement of surface condition since 2000. The introduction of a new contract in 2012 has provided the opportunity enhance the requirements. This paper focuses on the developments undertaken in two areas – rutting and surface disintegration. Rutting is a key indicator of condition, but the laser-based transverse profile systems used to quantify rutting can be adversely affected by features such as road markings. An approach has been developed to use high resolution transverse profile in combination with surface intensity measurements to remove the influence of such features. Surface disintegration is becoming a major source of deterioration on the SRN. This has required the development of an improved assessment method, which utilizes multiple laser texture measurements to identify disintegration over the full survey width. The research has lead to the publication of a revised survey specification for TRACS.