Deadly designs : the impact of road design on road crash patterns along Jamaica’s North Coast Highway

Abstract: Jamaica has struggled to curb the number of road crash fatalities, having had on average 25 fatalities per month between 2010 and 2014, while many more persons have been injured. The causes of crashes are multidimensional, however this study focused on understanding one aspect of reducing crashes - safe road design. The aim of this study was to determine the relationships between road design characteristics and fatal road crash distribution along the North Coast Highway (NCH) in Jamaica. The Anselin Local Moran’s I and the Getis-Ord Gi' models were employed to look at the distribution of crash hotspots. This paper also utilised Esri’s Weighted Sum Analysis tool to devise a scoring method for determining how safe or dangerous road segments were based on the presence, absence and type of road design features. The design variables selected for this study included bus stops, pedestrian crossings, traffic lights, intersections, places of interest, sidewalks, speed limit, soft shoulders, medians, lanes and roadside barriers. This study also used the zero-inflated negative binomial (ZINB) regression model to identify the empirical relationships between crash counts, crash types, road design features and safety scores. Results The ZINB model identified road segments with many places of interest (POIs), single lane, medians and many intersections as being significantly related to the segments with the most crash counts (irrespective of crash type). This study demonstrates how the spatial analysis of road design features and crash distribution can be used to determine how effective road design features are in advancing road safety and where to implement road safety plans.