HDM-4

Comprehensive book on the modelling of road user and environmental effects. It covers all aspects from vehcile operating costs to emissins. The models presented here formed the basis for the modelling in HDM-4, although the software does not fully implement the models.

Authored by Chris Bennett and Bill Paterson, the HDM-4 Series Volume 5 describes how to calibrate HDM-4. The report addresses a range of issues from Information Quality through calibrating pavement deterioration and road user effects.

This strategic planning document details the Information Technology (IT) strategy, system architecture, and software engineering framework for the development of HDM-4 under the ISOHDM project. Transitioning from the legacy DOS-based HDM-III model, this strategy outlines the adoption of modern object-oriented programming paradigms, relational database management systems (RDBMS), modular software design, and graphical user interface (GUI) standards suited for Windows operating environments. The document specifies the modular breakdown of the HDM-4 software suite, comprising core analytical engines for project analysis, program analysis, and strategy analysis, supported by comprehensive data managers for road networks, vehicle fleets, climate zones, and maintenance standards. System integration, data exchange standards (such as XML and SQL), software extensibility, and backwards compatibility with existing HDM-III database structures are emphasized. Furthermore, the report establishes quality assurance protocols, software verification testing procedures, user support structures, documentation guidelines, and international dissemination plans to ensure that the HDM-4 tool provides a robust, user-friendly, and maintainable software platform for highway agencies, consultants, and academic institutions worldwide. Overall, the report emphasizes rigorous empirical validation, standardized data acquisition protocols, and modular integration into the broader Highway Development and Management analytical engine. By combining physical principles with statistical calibration across international trial sites, this working paper provides a robust theoretical and practical baseline for highway authorities to evaluate long-term infrastructure policy options, allocate maintenance budgets efficiently, and maximize economic returns across regional and national road networks. In summary, this study provides highway engineers, transport planners, and economic analysts with an essential mechanistic-empirical tool for evaluating life-cycle