Insight into traffic data

In May 2020, Rijkswaterstaat’s unit for water, transport and the environment tasked Witteveen+Bos with preparing the annual INWEVA. We are working closely with Fileradar to achieve this. INWEVA identifies the traffic intensity of each road section of the Dutch highway network. 

These traffic intensities are important to Rijkswaterstaat, because this data is used throughout the country by various parties to perform calculations relating to air quality and noise levels caused by highway traffic. In addition, we use these intensities to develop a schedule of workable hours for Rijkswaterstaat. The schedule for each road section indicates when road work can be carried out with acceptable traffic inconvenience and serves as input for highway construction contracts.

At a large number of locations we obtain traffic intensities for INWEVA through means of permanent traffic measurements (via NDW, the Netherlands National Road Traffic Data Portal), using the well-known induction loops embedded in roads. Where there are no available high-quality or any permanent traffic measurements at a road section, we use an estimation methodology to produce an estimate by minimising the difference between the allocated intensity and the actual intensity at measured points. The new estimation methodology makes use of various sources of information for this purpose, such as the Origin-Destination matrices of the national traffic model, NRM, and actual speeds obtained from Floating Car Data. We presented the intensities, including the plausibility checks we performed, through means of an online web application that in addition to a presentation function also includes a collaborative function.

We have since provided the annual set of figures for two consecutive years to the satisfaction of Rijkswaterstaat: INWEVA20 in March 2021 and INWEVA21 in March 2022. In these exceptional years, during which there was less traffic on the road and traffic patterns were different due to the corona pandemic, we succeeded in delivering reliable traffic figures. This was the result of two intensive years of effective collaboration between Witteveen+Bos, Fileradar and Rijkswaterstaat, whereby the objective set by all parties was to create a high-quality end-product and this objective has been achieved. The fact that there is mutual trust in this collaboration and the developed product is evident from the contract extension granted by Rijkswaterstaat for the preparation of INWEVA22.

The acquired knowledge and the methods developed for INWEVA and the schedule of workable hours offer opportunities for developing new tools based on traffic data from the main road network, as well as the underlying road network, for example to provide insight into traffic intensities and hindrance on road sections.