N223: Trial: Innovative Noise Abatement Measure for Heavy Traffic

The Province is starting a research into the effect of a new noise abatement measure on the N223: the so-called WhisStone for heavy traffic. The WhisStone reduces the traffic noise caused by heavy traffic and freight traffic and is applied in combination with the existing WhisStone for passenger car traffic.

The WhisStone has been fitted with grooves and are placed in the shoulder along the road, next to the tarmac. These plates redirect the sound upwards, whereby the buildings along the road experience less noise pollution. The noise nuisance is limited this way, and living conditions are improved. An additional advantage is that these plates also improve road safety, because they also serve to strengthen the shoulder.

An earlier test proved that this measure is useful. During the trial, its effect will be tested in practice. Because this concerns an innovative noise abatement measure that has not been applied before, measurements will be carried out after the construction to determine the effect in practice. A hedge will be removed temporarily during this trial, to be replaced after the trial has been completed.


The residents in the immediate vicinity will be asked to complete a questionnaire about their experience of the new noise abatement measure.

Noise Nuisance

Prior to the trial, the WhisStones will be installed along the N223, which will cause limited hinder for road users. During the trial, outside the rush hour, half a lane will be blocked on the main road for a short period. Temporary traffic lights will direct the traffic in turn around the construction work.

Smart Solutions

The Province of Zuid-Holland aims for a smooth and safe use of the provincial road network. Many people live and work along these roads, and might experience sound nuisance caused by the traffic. Investments in accessibility are closely linked to investments in the living conditions by applying sound abating measures such as quiet tarmac, and sound barriers. All the same, these measures do not always offer the right solution. Smart noise abating solutions that can be applied in such circumstances have been sought in collaboration with the business community.