[australis]

A similar effect can be noticed on sections of roads with dedicated overtaking lanes. Cars that are travelling below the speed limit for long stretches of road (and can't be overtaken due to the road), tend to speed up to the actual speed limit when an overtaking lane comes along - likely due to the more open road, they feel safer driving faster, etc.

This makes it more difficult for all the (often frustrated) drivers behind to pass the slow car when the time comes, often meaning they put on the afterburners and exceed the speed limit to overtake - which could lead to more accidents, especially if they are trying to squeeze past at the end of the overtaking section, if it is quite short, or there are many cars stuck behind as 'prisoners'.