Most of the drivers exceed the limit on 30 km/h roads. Often this is done at speeds more than 10 km/h too fast. However, there are big differences between locations. This is shown by occasional speed measurements at specific locations. On a national scale there is no representative data of the driving speeds on 30 km/h roads.
The occasional measurements are generally carried out in the framework of an investigation into the effects of speed measures. The pre-measurements of these studies give an indication of the speed driven on road sections without physical speed inhibitors such as road humps or road narrowings. For example, measurements in ten 30 km/h locations in the Province of Zuid Holland in 2010 [20] found that the average driving speed was 36 km/h. On average, about 70% of drivers violated the limit. About half of them violated with more than 10 km/h. On some of these roads was the share of offences was below 30%, on others the share was as large as nearly 95%.
In 2012, similar results were found by measurements on more than twenty 30 km/h locations in Limburg [21]. Per hour the average speeds ranged from 33 to 40 km/h, and per hour the percentage of drivers who exceeded the limit by more than 10 km/h ranged from 34 to 40%.
In 2017, more recent measurements were made at ten 30km/h locations in the Province of Zuid-Holland [22]. These measurements found average speeds driven ranging from 25 to 37 km/h. The share of vehicles that exceeded the limit ranged from 26 to 85%.
