Identification of Homogeneous Sections from Road Data

Abstract

For highway design or maintenance projects, a long road stretch needs to be delineated into some homogeneous sections, on the basis of various pavement responses, such as, subgrade CBR value, field moisture content, soil type, deflection, pavement distress parameters, roughness, etc. Cumulative difference approach (CDA) for identification of homogeneous sections is suggested in the AASHTO Guide for Design of Pavement Structures [AASHTO (1986) Guide for Design of Pavement Structures, AASHTO, Washington, DC, pp. III-17–III-20 and Appendix J; AASHTO (1993) Guide for Design of Pavement Structures, AASHTO, Washington, DC, pp. III-19–III-24 and Appendix J]. This paper identifies some of the limitations associated with this method and suggests improved yet simplistic methodology for identification of homogeneous sections based on a combined approach of classification and regression tree (CART) and exhaustive search. Examples are drawn from synthetic and realistic data.

Keywords:

• Homogeneous section
• Cumulative difference approach
• Change-point
• AASHTO Guide
• CART method

Notes

^†Current address: Assistant Systems Engineer, Tata Consultancy Services, C-56, Phase-2, Noida 201 305, India E-mail: [email protected]

^‡http://www.cf.ac.uk/maths/stats/changepoint, last accessed on 25th June, 2002)

^¶http://www.umtri.umich.edu/erd/roughness, last accessed on 25th June, 2002