A New Approach to Increase Road Safety – the Benefits of Adding Historical Accident and Speed Data to Transportation Planning and Simulation Tools



A New Approach to Increase Road Safety – the Benefits of Adding Historical Accident and Speed Data to Transportation Planning and Simulation Tools

Authors

Timo Hoffmann, PTV Group, Michele Giuliani, TPS

Description

A case study examining the benefits of using integrated accident data as well as network-wide speed data in transportation planning and simulation tools to foster a safe planning workflow.

Abstract

This case study examines the situation in a model region, where road infrastructure planning and road safety analysis based on data of a structured accident database as well as additional network-wide speed data are brought together.
During the study period in the first half of 2013, new tools have been introduced that enable the local traffic planners to perform road safety analysis tasks based on historical accident data and use this information in traffic simulations on multiple levels, from a network-wide network safety management use case to a single intersection black spot management use case. In addition to the new tools and the incorporated historical accident data, commercially available speed profile data was used to enhance the analytical process. The aim of using such an integrated approach is to be able to consider road safety factors better during the planning of regulations or design of road infrastructure as opposed to doing a subsequent analysis of the road safety implications separately.
One of the main outputs is a ranking of infrastructural elements (road sections or junctions) based on a risk exposure index that considers the accident rate, the LOS of the network elements, the measured speeds and the traffic flows. In addition to this network safety management (NSM) use case, black spot management (BSM) techniques with semi-automatic black spot detection were used to identify road sections and intersections to be analyzed at a higher detail level. This in-depth analysis was accomplished by assessments of traffic subnetwork parameters on a mesoscopic scale and dynamic microsimulation models of the traffic flows.
The availability of additional data from the speed profiles, the analysis of the meso- and microscopic simulations as well as the possibility to correlate the attributes of the recorded accidents and with microscopic dynamics of the traffic increases the understanding of accident black spots and selection of mitigation efforts.
The approach described in this case study, which is based on the integrated chain of tools and models at different detail level without data boundaries within the PTV Vision Traffic suite, and the use of innovative data sources not commonly part of road safety assessments (e.g. network wide speed profile data), proved to be highly time and result efficient and is able to contribute to the definition of the procedures for planning the measures aiming to cut down road accident rates.

Publisher

Association for European Transport