Constructing and maintaining the road network is an expensive endeavour. But with the help of specialised satellite positioning equipment developed under a Galileo FP7 project, the route to optimal road quality and cost saving could now be a matter of course.
The majority of European motorways and roads have an asphalt top covering. However, asphalting is a complex process – an art in fact - in which the parameters of temperature and thickness of the asphalt layer, compaction and evenness each play an important role in determining the final quality of the road surface.
With high traffic volumes, even the smallest flaws in asphalt covering will soon lead to cracks, unevenness and potholes. The consequence is that the road must be reworked or renewed ahead of the original planned time with significant economic penalties.
The objective of the ASPHALT (Advanced Galileo navigation System for asPHALt fleeT machines) project, a European Commission funded FP7 project managed by the European GNSS Agency (GSA), was to improve the quality of road coverings and to optimize the various process sequences with the help of satellite positioning technology. As a result, maintenance costs for the road network can be significantly reduced.
Ionosphere helps asphalt
The results of the project were on display at the concluding project meeting that took place in early May 2012 close to Enspel in Germany. During the two-day meeting accurate satellite control of asphalt laying machines was demonstrated showing that, with the aid of satellite navigation, road construction can be significantly improved in the future.
At the heart of the technology is a special Galileo/GPS/EGNOS receiver that was developed by the Fraunhofer Institute for Integrated Circuits. This multi-frequency receiver has a number of advantages over previous devices. It uses two frequencies which reduces disturbances from the ionosphere and therefore improves the precision of positioning. Also the combination of GPS and Galileo improves the availability of satellite signals and special algorithms calculate the position.
Thanks to the highly precise control of the road-making machines, an even thickness of the asphalt layer can be achieved and a high quality road covering guaranteed.
Process perfection
In addition, process sequences and supply chains in road-laying were analyzed and optimized during the project. There are three basic steps in the process: the provision of the asphalting materials; its deposit on the ground; and the compacting process.
With the help of data logging from start to finish, and networking of all components, the sequence of tasks in road construction can be improved and simultaneously documented. The most important parameters, such as the asphalt temperature, layer thickness, and compaction, are exchanged between the various machines used in the road making process. In this way the partial steps can be ideally coordinated with each other. In the future, the complete monitoring and documentation of the process sequences can yield significant benefits for public authorities and also road-construction companies.
The project was coordinated by MOBA Mobile Automation AG, a German company with 40 years experience supplying automation systems to the road construction business.
Project coordinator Marcus Watermann of MOBA comments: “The potential cost savings from the ASPHALT project outcomes are impressive. If the life-period of the average road surface can be increased from 10 to 11 years this can realize cost saving of € 4.5 billion per year within Europe. Savings of a similar magnitude are also possible through optimisation of the process sub-steps of road-laying as well as secondary savings by less traffic jams and air pollution.”