Can roads truly be made safer? Yes, they can, and this handbook shows road designers and traffic engineers how, through a better understanding of road users – the “human factor”. Over a million people are killed every year on the world’s roads. Road user error is often concluded to be one of the main factors contributing to road crashes, and many in the road safety world believe that road user error is inevitable. But it need not be inevitable in a transport system that is designed around the needs and capabilities of its users. This is where road designers and traffic engineers have a vital role to play. Over many years, they have developed their skills to optimise traffic movement and maximise safety. But they don’t always get it right. One likely reason is that they may lack a basic understanding of the abilities, limitations and needs of the very people they are designing for – road users. The scientific discipline of “Human Factors” exists to support road designers and traffic engineers, so that they can put road users at the centre of their design thinking. It provides them with data, principles and knowledge that can be applied to designs to optimise human performance, minimise error and make the road transport system safer and more user-friendly. Human factors is not just of interest to professionals involved in behavioural programmes for road safety, it is also vital for the development of the professional skills that road designers and traffic engineers need, to do their job effectively. This handbook – the first of its kind – seeks to show how an understanding of human factors can be applied in practical ways to the day-to-day tasks of designing and managing the road system to make it a safer and more user-friendly place to travel. The handbook is structured in a way that takes the reader through the fundamentals of road safety and human-centred design and then looks at road user capabilities, limitations and design needs before the majority of the chapters look at the practical application of this knowledge to the various aspects of road design and traffic management that professionals are involved in. This handbook is also designed as a textbook, putting the human factor at the heart of basic education and training in road and traffic design for undergraduate and postgraduate students. Here is the how and why of human factors for road designers and traffic engineers in one convenient volume based on the authors’ extensive knowledge, experience and expertise. Packed with case studies, human factors checklist questions, photos, do’s and don’ts, examples and practical exercises, it is a must-have for students and professionals alike.