Quantifying the Post-construction Safety Impacts of Road Infrastructure Projects for International Development Institutions

Quantifying the Post-construction Safety Impacts of Road Infrastructure Projects for International Development Institutions

Nominated for The Neil Mansfield Award


Uven Chong, Millennium Challenge Corporation


Traffic safety is an important and under-quantified factor for road construction projects in development institutions. We developed a method to account for road safety impacts that can be used to support design decisions in construction projects.


Investment in road infrastructure is an important mechanism for development institutions targeting poverty alleviation in low and middle income countries (LMIC). At the same time, increased motorization has not been supplemented by sufficient road safety measures. Road traffic accidents are a leading cause of fatalities that occur primarily in LMICs. The World Health Organization (2013) estimates that 92% of road traffic deaths occur in LMICs and only 7% of the world’s population live in areas with adequate road safety regulations.

In planning for road construction, most development institutions consider the costs of building a road and the economic benefits from increased mobility. Increasingly, environmental factors (e.g. land degradation and climate change) are also quantified in the cost-benefit analysis. Safety costs, if considered at all, are typically confined to the immediate impacts during construction (e.g. redirecting existing traffic and worker health). Few have guidelines that anticipate and minimize road accidents after the road is fully functioning. The purpose of this paper is to present a method for quantifying post-construction safety impacts to support design decisions in road construction projects.

We developed a scenario-based cost-benefit model that is based on the US Federal Highway Administration’s Crash Modification Factors (CMF) Clearinghouse database (2013). The CMF database is a collection of 259 studies that quantify the impact (e.g. change in fatality) of specific road safety interventions (e.g. pedestrian bridges, road shoulder width widening). The database consists of 3099 crash modification factors and is continually updated. Using the CMF, it was possible to test the costs and estimated benefits of adding specific safety interventions to planned road projects. This provides quantitative support to justify decisions to implement road safety enhancements, which can ultimately help mitigate some of the growing road traffic fatality burden in LMICs.

World Health Organization (2013) 10 Facts on Global Safety [online] http://www.who.int/features/factfiles/roadsafety/facts/en/index1.html

US Federal Highway Administration (2013) Crash Modification Factors Clearinghouse [online] http://www.cmfclearinghouse.org/


Association for European Transport