[Ottolay]

It's a known hypothesis. Additionally when there is less traffic, drivers feel safer and are more likely to tune out by checking their phones, etc.

The book,Confessions of a Recovering Engineer(1), talks about this.

(1) https://www.confessions.engineer

[thaway2839]

The Not Just Bikes Youtube channel consistently points out how Dutch street design focuses on making driving seem "scarier" to lower driving speeds as a safety measure. These aren't ridiculous measures. These are sensible measures such as eliminating one way lanes where possible (people tend to drive much faster in one way lanes), not having car lanes that are excessively wide, having level crossings for pedestrians, which means it's the cars that see a bump in the road, etc.