The Guardian has been playing with data that TomTom navigation software collects on congestion, the traffic index. The article has a range of graphs for cities worldwide, showing how city traffic is reduced due to various measures trying to stem the pandemic.
At the bottom of the article is a small search box where you can get the graphs for cities not mentioned in the article.
TomTom’s index contains it seems quite a few Dutch cities, perhaps because it’s a Dutch company. So I went ahead and grabbed a few screenshots for Dutch cities, amongst which my hometown.
TomTom sells services on the data they collect, so there doesn’t seem to be anything available to download for yourself. They do have a similar search tool on their site which gives slightly different perspectives on the data they have. Below for Amersfoort the traffic density for the past week. It basically shows us what we feel outside: every day is like Sunday traffic.