20 March 2019
Passage piéton équipé des dalles Flowell
Groupe Colas
On 20 March this year at the “Biennale des Territoires” symposium, Cerema and Colas signed a memorandum of understanding to support experimentation on Flowell, an innovative dynamic luminous signage solution.

Colas has developed an innovative system of slabs made up of encapsulated LEDs, which are glued directly onto road surfaces and connected to the electricity grid.

The purpose of Flowell is to improve safety for road users, especially pedestrians, by illuminating horizontal signage. This system will also be able to modulate the periods of time when traffic lanes are used and reserved on a road, thanks to its dynamic lighting capabilities.

Experiments in real conditions

Article du moniteur sur l'expérimentation à Mandelieu la Napoule

An initial experiment providing luminous reinforcement of a pedestrian crossing. is under way in Mandelieu-la-Napoule. It started on 1st March 2019. Flowell will be tested in real conditions on one of the main crossroads in the town, to analyse the advantages of the Flowell solution for reducing dangerous behaviour, on four pedestrian crossings that are particularly busy.

Other use cases are also being considered for new experiments: reinforcement of user perception of public transport lanes, adaptability of traffic lanes depending on the time of day (commuter traffic) and also adaptable parking systems, etc.


Cerema will carry out two main missions over a 3 year period:

  • Scientific and technical support for the experiments: this mission will take place in 3 phases corresponding to the experiment (before, during, after):

    • Expert appraisal of the definition of the assessment protocols;

    • Analysis of implementation of the assessment protocol;

    • Scientific appraisal of the experimentation report.

    • As part of this mission Cerema will produce a “Definition of the innovation and the relevant domains” comprising assessments of the domains that are relevant for the innovation, the choice and layout of the experimentation sites, the management of degraded modes and the operational scenarios adopted according to the use cases.

  • Assessment of Flowell’s optical visibility. The aim of this mission is to define a methodology for assessing Flowell’s visibility. The measurements of photometric values (intensity, illuminance, brightness) traditionally used to quantify the visibility of infrastructure elements must be adapted to this innovation (dynamic luminous horizontal signage). For this purpose, the Cerema will set up an experimental platform.

In order to perform these missions, Cerema will deploy its expertise in assessment of experiments and metrology of luminous systems.

Signature of the memorandum of understanding between Cerema and the Colas Group at the Biennale
Signature of the memorandum of understanding between Cerema and the Colas Group

Cerema will adapt its appraisal to each use case, and will make sure that the assessment is comprehensive, covering all of the uses and users.

Special attention will also be paid to the technical assessment of the product (sustainability, maintenance, consumption, etc.).

On completion of these experiments, and according to the results of the assessment, this type of luminous horizontal signage could be incorporated into the national regulations.

The memorandum of understanding between Colas and Cerema was signed on 20 March at the Biennale des Territoires symposium, a Cerema event devoted this year to transport networks.