Speeds on Netherlands’ 30 km/h roads still too high, SWOV states

Source: CROW Fietsberaad Image source: Pourya Gohari, Unsplash

Research by SWOV, the Netherlands’ Institute for Road Safety Research, has found that there is speeding on a large scale by motorists on roads where the speed limit has been reduced from 50 to 30 km/h. In cases where the road layout has been modified, speeds are lower.

The SWOV study analyses speed behaviour on regional access roads with a speed limit of 30 km/h (GOW30), which were introduced in 2020. These roads were designed to address the mismatch between the traffic function of certain roads and the existing 50 km/h speed limit, which was considered neither safe nor appropriate. Data was gathered at 54 GOW30 locations using Floating Car Data from TomTom Move.

Average speed findings

Results showed an average speed of 35.3 km/h, while an upper speed of 43.5 km/h was not exceeded by 85% of motorists. Roads which included features such as median strips (central reservations), parking facilities, and/or an open or semi-open surface seemed to result in lower speeds.

The effects of redesign

Taken on average, the speed reduction on the 54 roads in the sample was an average of 4 km/h following the introduction of a lower speed limit. However the speed-reduction effect is noticeably greater where there had been a redesign of the road layout as well as a reduction in the speed limit. 22 of the locations in the sample had not been redesigned, and saw a speed reduction of 2 km/h. The 32 redesigned locations saw a reduction of approximately 5.5 km/h.

Redesign methods included the replacement of a closed surface (asphalt) with an open surface such as paving stones, and the construction of raised intersection platforms. An open surface sees a speed decrease of approximately 4 km/h, and raised intersection platforms approximately 3.5 km/h. If combined, the measures result in a reduction of 9.5 km/h.

Assessing the results

SWOV has compared the findings with its guidance on the provisional design characteristics for GOW30 roads, finding that the positive effects of the open paving and raised intersection platforms aligned with recommendations. SWOV says that additional research is required to ascertain other guidance elements, such as centre markings and the physical separation of driving directions and parking facilities.

SWOV plans in 2026 to conduct a road image study, focusing on the influence of design characteristics on speed behaviour.