Out of sight, sound and smell
The A4 Delft–Schiedam cuts straight through the natural and polder landscape of Midden-Delfland, with its pollard willows, black-tailed godwits, sheep and ditches. In this open landscape, anything that rises above the road or extends beyond its profile is highly visible.
To reduce the road’s visual impact and noise levels, the A4DS is partly semi-sunken, partly fully sunken and partly enclosed in a tunnel. In some sections, the road lies up to six metres below ground level. ‘Out of sight, sound and smell’ is the motto of the A4DS route decision.