Impact of street layout on traffic collisions and near misses

Background 

Over the past few decades, road design has been developed with a strong focus on safety in order to reduce the number of accidents and fatalities on the roads. Road traffic injuries are the leading cause of death among young people aged 5-29 years, with approximately 1.3 million people dying each year as a result of road traffic crashes (WHO, 2022). A further 20 to 50 million people suffer non-fatal injuries, many of whom sustain disabilities. Vulnerable road users, including pedestrians, cyclists, and motorcyclists, account for more than half of all road traffic deaths. The World Health Organization (WHO) has predicted that road traffic casualties will become the fifth leading cause of death by 2030. To combat this, the United Nations General Assembly has set an ambitious goal to reduce 50% the global number of deaths and injuries resulting from road traffic crashes by 2030 (WHO, 2022).

According to recent statistics, Great Britain experienced approximately 1,760 fatalities, 28,044 cases of serious injury, and 107,209 cases of minor injury as a result of reported road collisions in the year ending June 2022 (GOV.UK, 2022). Furthermore, the economic impact of these incidents is significant, with an estimated annual cost of approximately £16.5 billion, which includes expenses related to medical care, emergency services, lost productivity, and damage to property (Statista, Road accident costs by severity Great Britain 2020).

Traffic collisions can have a significant negative impact on traffic flow, causing traffic congestion, reduce capacity, longer journey times, decrease journey time reliability, and reduce resilience of the road network (TFL, 2017). Studies estimate that collisions accounted for 28% of the congestion on the Transport for London Road Network (TLRN) in 2010/11(TFL, The road safety action plan for London 2020). By reducing the number of collisions, it is possible to mitigate these wider impacts and improve the overall efficiency and safety of the road system.

Improving road safety, with a particular focus on vulnerable road users, continues to be of utmost importance in light of the persistent occurrence of accidents. This issue warrants extensive research and attention to identify effective strategies and interventions that can mitigate risks and ensure the well-being of all individuals on the road. 

Study Aims and Objectives 

The main objective of this research is to investigate the impact of street layout on the occurrences of near misses and collision rates, with a focus on junctions and areas between junctions. The study aims to identify key factors that contribute to high-risk areas and critical street layouts, with the ultimate goal of preventing collisions and reducing the resulting injuries.

The available literature on road safety provides a broad overview of various factors that affect road collisions, including driver and vehicle behaviour, gender, population, speed, age, weather condition and lighting condition. Furthermore, most safety analysis relies on reported accident data; however, the author has access to a new and district data source that involves near misses. To achieve the study objectives, the research will utilize new data source that involves near misses, in addition to reported collision data. The analysis will explore the correlation between reported collisions/near misses and street layouts and design, taking into consideration factors such as traffic volume, road surface roughness, vehicle speed, weather conditions, lighting conditions, junction and street design. The research will identify any significant trends or patterns in the data that can inform the design and planning of safer streets, contributing to improved road safety.

The study's findings will contribute to the Vision Zero Strategy of the Mayor of London, which aims to eliminate all traffic fatalities and severe injuries from London streets by 2041 while increasing safe, healthy, and equitable mobility for all. Through the identification of high-risk areas and critical street layouts, the research will provide valuable insights into road safety, ultimately contributing to the development of effective strategies for the prevention of collisions and injuries on London's streets.

Methodology & Data Preparation

To investigate the potential impact of street layout design on near misses and collisions rate, the researcher intends to examine two sources of information.

1. To extract and analyse London collision data published by the Department for Transport (DfT Stats 19) which is based on records submitted to them by police forces. 
2. To analyse near miss data collected from Mercedes Benz customer cars and van. The vehicles are equipped with a high range of Advance Driver Assistance Systems (ADAS) which support the driver. 

Figure 1: Mercedes-Benz Advance Driver Assistance System being used to collect data.

Mercedes Benz has agreed to provide the data for academic purposes, recognizing its value in advancing research and promoting knowledge in road safety. The customer provided explicit consent to share anonymised data for 3rd party use cases. Only data from vehicles and customers who gave their consent are used in this study to protect their privacy. 

Based on the findings of the analysis, the study will recommend potential interventions to improve road safety in high-risk areas and critical street layouts. These interventions may include the implementation of street layout upgrades, traffic calming measures, improved lighting conditions, and better road surface conditions. The findings of the study will also inform future road safety policies and strategies in London, contributing to the goal of achieving zero traffic fatalities and severe injuries in the city by 2041.

Overall, the study will provide valuable insights into road safety in London and contribute to the development of effective strategies for the prevention of collisions and injuries on the city's streets. The study's findings will have practical applications for road safety practitioners, policymakers, and urban planners in London and beyond, helping to create safer and more equitable mobility for all.
 

MSc Project Report 

Hamid, Mohammad Hamza
Supervisor: Professor Peter Jones and Professor Nicola Christie
MSc Transport Engineering Programme
March 2023

Joint programme between University College London and Imperial College London
UCL Department of Civil, Environmental and Geomatic Engineering

MSc Transport Engineering Programme 

I am deeply passionate about addressing the complex transportation challenges that exist at various levels, from local street issues to global concerns such as climate change. The MSc Transport Engineering programme aligns perfectly with my interests and aspirations in this field.

Through this programme, I have gained a comprehensive understanding of the theoretical foundations and practical considerations necessary for designing and analysing efficient, safe, secure, and sustainable transport systems. The opportunity to evaluate transportation projects and policies while taking into account the multidimensional aspects of political, social, environmental, safety, security, commercial, and financial factors greatly appeal to me.

Moreover, the emphasis on problem-solving and the opportunity to work with transport organizations and communities further excites me. Being able to apply the knowledge and skills acquired during the programme to real-world challenges is a valuable experience that will prepare me for a future career in transport planning, engineering, operations, management, or policy.

This course equips students for further PhD research in this specialist area or a future career in transport planning, engineering, operations, management or policy. This programme prepares next generation of transport and mobility leaders with the knowledge and skills required to create systems that are sustainable, accessible, equitable and works for everyone.