Hans Monderman, the pioneering Dutch traffic engineer, died on Monday 7 January, near his home close to Drachten, in Friesland, aged 61. As one of the most innovative and challenging of thinkers and practitioners in his field, he will be widely mourned by the many professionals, politicians, academics and ordinary people from across the world who admired his radical and challenging approach to bringing simplicity and humanity to the design of streets and public spaces. Monderman trained as a civil engineer before studying traffic engineering and accident investigation. During the 1970s, he was appointed head of road safety for the northern three provinces of the Netherlands. Always doubtful about the conventional traffic engineering vocabulary of signs, markings, barriers and traffic calming, he began to explore the potential for improving safety and the quality of public life through encouraging simple human interaction and negotiation among road-users. During his career with municipalities across northern Holland, he initiated more than 100 schemes which established a new direction for reconciling the relationship between people, places and traffic. Convinced that humans possessed skills in negotiating and interaction that were being suppressed by conventional rules and regulations, Monderman’s more recent work began to explore the potential for simplicity and integration between engineering and urban design. More complex schemes in Drachten and Groningen drew his work to the attention of a worldwide audience. He is most associated with the removal of signs, signals and road clutter, but it is the recognition of human intelligence and complexity, and the importance of place, for which he will be best remembered. In 2007, his work was recognised through the World Technology award and an honorary PhD in traffic planning. But it is as an inspirational speaker and practical innovator that Monderman will be best remembered by those keen to promote simple human values and civility in the public realm.