Flowell, a luminous active roadmarking designed to enhance safety and improve how we share public space

01 March 2022 - Published by CIE Communications

Flowell, an innovation by the Colas Group, is a sensor-triggered luminous active road marking designed to enhance visibility for vulnerable road users, improve how we share public space and foster smoother, safer traffic. The Flowell solution makes it easier to respect traffic laws, promoting calm behavior in potentially dangerous zones.    


To enhance safety, the system only activates in the presence of users. Thanks to trigger sensors, the luminous active road marking lights up at the right signal, at the right time and for the right user.


The main objective is to change user behavior, encourage people to bettercomply with traffic laws and improve how we share public space.


The challenges Flowell addresses may differ from one community to another:

• Securing soft mobility: by enhancing visibility for pedestrians at crosswalks and for cyclists at intersections, or other potentially hazardous spots;

• Improving how public space is organized by highlighting the areas dedicated to each type of user, in potentially hazardous intersections;

• Adapting infrastructure by modulating public space according to traffic levels and specific needs, for example by giving priority to certain vehicles at specific times, or by allocating space for a specific use (modular parking spots, delivery zones, etc.).


How does it work?

Flowell is comprised of panels containing LEDs encapsulated in a multilayer substrate, connected to the electrical network. The thin panels - only 7 mm - are also connected to control terminals. Flowell is glued to or embedded in the pavement, and its surface roughness provides grip equivalent to a conventional wearing course.

Flowell can take on different shapes and forms to meet specific needs. Today, the solution is sold in strips for crosswalks, red light lines, and chevrons, and more complex shapes are also possible.


In the Parisian business district of La Défense, pictograms in the shape of a bicycle have been installed to secure new bike paths. The urban environment in the neighborhood has been designed for car traffic only, which means that securing the new paths is crucial. The Flowell bicycle only lights up when the rider has priority and a bicycle has been detected on the cycle path.


In Lyon, Flowell panels in the shape of a tram were glued to the roadway to warn pedestrians and bicycles that the tram is about to pass through, to make sure the users yielded to oncoming trams.


Keeping soft mobility safe is a priority, but there are other uses dedicated to improving how we share public space. For example, Flowell makes it possible to share parking places, e.g., reserving them for delivery trucks in the morning, then for residents and retail customers for the rest of the day during the week and weekends, as is the case on the Saclay plateau, near Paris.


Beyond this specific function, Flowell's versatility can adapt to other needs on roads, railways and airports, in particular guiding vehicles. 


Flowell is currently being trialed on a number of sites, to test the technology and its applications: crosswalks, bicycle crossings, sharing of public space, etc. The preliminary feedback on behavior shows that the solution makes a real difference. Trial sites are now being rolled out beyond France.