Taming the arterial. How to build safe, low speed, high volume streets.


Many planning and engineering professionals are looking for better tools to create safer environments for people walking and cycling. Separated bicycle ways, comfortable footpaths and safe crossing points and intersections form part of the standard toolbox in most jurisdictions across North America. Many of these tools require a reallocation of street width from the motor vehicle to vulnerable road users. While this is a necessary part of creating mobility options and addressing the challenges of equity, climate change and vision zero, it is often met with resistance from within or outside the organization. Reducing road capacity and lowering the level of service for motor vehicles is still considered controversial in many cities and states. A street design that delivers both a reasonable motor vehicle throughput yet delivers safety and a higher level of comfort for all road users is necessary. In The Netherlands, this challenge is met by a concept called “LARGAS”, an acronym that means as much as “driving slower goes faster”. This is a type of arterial road where a single vehicle lane is catered for, but a high flow of motor vehicles is maintained through the reduction in number of traffic lights, innovative intersection design and traffic calming measures. On these roads, the design speed is set at 20 or 25 miles per hour, bicycles and pedestrians enjoy separated facilities and vehicle flow is slower but continuous. The result is noticeable with flows up to 14.000 vehicles per day on a two-lane street. This design solution has recently been adapted by Mobycon to the North American context in Canmore, Alberta. In this presentation, the concept of LARGAS in The Netherlands will be presented, the necessary, and optional design elements will be explained and the North American design concept will be presented. It will provide inspiration and guidance to traffic engineers, planners and city officials to expand the toolbox and re-imagine the possibilities of road diets. This design concepts helps to humanize arterial roads without needlessly compromising on traffic capacity.

Presented by

Lennart Nout Lennart Nout, Mobycon

Lennart has 10 years of experience at all levels of street design. From developing strategies and policies to planning, design and community engagement. Through working in a great variety of countries like New Zealand, Australia, Canada, the USA, United Kingdom, he has developed a global perspective and unique method for translating international best practice to a local context. After his Dutch experience and education, he specializes in planning and designing for walking and cycling, vision zero and traffic calming.