His work compelled transportation planners and highway engineers to look afresh at the way people and technology relate to each other.

Monderman found that the traffic efficiency and safety improved when the street and surrounding public space was redesigned to encourage each person to negotiate their movement directly with others.

[5] Monderman took it as a given that for several generations, motorised traffic will remain an essential feature of European economies and their spatial fabric; in effect, he has taken this as his technical and policy target—a problem that simply will not go away.

Against this background, he reviewed technologies and practices of street design, and stripped away those he felt insufficient or counterproductive.

One of the better known of Monderman's accomplishments is the Dutch Woonerf, or "Living Street" project, which originated from a basically unplanned citizen initiative in Delft in 1968.