Challenge
The challenge posed by the Infrastructure Section of the Conservation Service of the Department of Infrastructure and Territorial Development of the Bizkaia Provincial Council is entitled: “How can the visibility of road markings be improved in rainy and adverse weather conditions?”
This challenge addresses the needs described below:
- How could the level of retroreflection of road markings be maintained in rainy conditions, in areas without lighting and with low visibility?
- How could the user’s visibility of road markings be guaranteed in adverse weather conditions and at any time?
- How could the solution meet the technical requirements demanded by the nature of the infrastructure in an economically sustainable way?
The Bizkaia Provincial Council, as the owner of the road network of the Historical Territory of Bizkaia, is responsible for its conservation and maintenance. This road network is made up of a total of 1,241.4 km, with a traffic volume of 4,592.8 million vehicle km per year. [1].
One of the elements of the infrastructure of road networks is road markings. These markings are defined as markings made on the pavement to separate traffic lanes, continuous no-overtaking lines, lines separating the hard shoulder from the carriageway and any other type of lines, words or symbols applied on the pavement to regulate vehicle and pedestrian traffic.
It is an essential component for channelling traffic, indicating the presence of possible obstacles and providing visual information throughout the journey in all weather conditions. It is therefore a key element for improving visibility on the road and promoting road safety as, in addition to defining lanes, it signals priorities and warns of possible hazards.
In order to maintain these road markings, the Department of Infrastructure and Territorial Development invests a total of €1,500,000 in its conservation each year.
These maintenance and conservation actions are carried out in accordance with the provisions of Standard 8.2-IC on Road markings [2], PG-3/75 of the Ministry of Public Works [3], subsequent updates and other applicable regulations.
The need for annual investment is related both to the need to address wear and tear and the need to maintain the necessary level of retroreflection. This is usually done by repainting road markings with paint and reflective microspheres in accordance with PG-3/75 for these work units.
However, retroreflective performance in heavy rain is significantly reduced. The accumulation of water on the roads and the formation of a film of water reduces the reflectivity of the glass microspheres. This film can cover the surface of the microspheres, reducing the amount of reflected light and therefore the visibility of the road markings. In turn, the angle of light reflection may be affected in heavy rain.
Despite the maintenance efforts and investment made, in adverse weather conditions, users do not have good visibility while driving.
This challenge aims to find an innovative solution that addresses the needs aforementioned.