Round robin tests in the Netherlands

This article has been written by Marius Nagelhout (Asset.Insight.) and Arco Blanken (Dutch Rijkswaterstaat) (representing CROW Workgroup Road Measurements). They will give a presentation regarding the subject round robin tests at the European Road Profile Users' Group (ERPUG) Forum which will take place in Madrid on 18 to 19 October 2018.    In the Netherlands we have the workgroup road measurements. This workgroup operates under responsibility of the CROW. CROW is a national knowledge institute and in the CROW Workgroup Road Measurements the following parties participate: Rijkswaterstaat Provinces Municipalities Road measurement companies Contractors


Certification and regulations on road measurements

The workgroup is responsible for certification and regulations on road measurements. For certification of road measurement equipment there are six round robin tests:

-      High Speed Road Profilers (HSRP)

-      Wet and dry skid resistance (Dutch method)

-      Falling Weight Deflectometers (FWD)

-      Close-ProXimity method (CPX) and Statistical Pass By method (SPB)


Round robin test HSRP


The HSRP is used for measuring the IRI and for acceptance measurement on new pavements. For the acceptance measurement on new pavements it’s needed to be certified. Every year there’s a round robin test organized with 12 measurement vehicles in 2017.


Round robin test wet and dry skid resistance


Measurement of the wet skid resistance is done for monitoring and acceptance of new pavements. The dry skid resistance is used for acceptance of new porous asphalt, because on this type of asphalt bituplanning can occur direct after completion. For conducting any skid resistance measurement by the Dutch method it’s necessary to be certified. In the round robin tests the measurement vehicle and tires are tested.


Round robin test FWD


Since the nineties of the last century approximately every two year a round robin test is held. Objectives of the round robin test are:

-      determination of repeatability of each FWD;

-      computation of the FWD correlation factor;

-      accuracy and precision of temperature recordings.


At the last round robin test in 2017 there were 14 competitors from Europe.


Round robin test CPX and SPB


In 2017 the CPX round robin test was organized for the second time and the SPB round robin test for the first time. Goal of the round robin test was to test the protocols and in the future this round robin test will be held every two year.


Round robin tests in general


The purpose of round robin tests is to minimize the spread of measurement results and to get more comparable measurement results. We want to give more insight in our experience with round robin tests and to exchange information about round robin tests with other road owners and data providers.