This is a form of sampling bias. The quick projects are only there briefly, so you're less likely to see them. Everyone sees a slow project that has some scheduling disaster occur, like a strike or a supply shortage or a government failure of some kind.
You don't know just from driving by whether 99.9% of projects are quick and efficient.
Or they might live in a place with an enriched and proliferate construction mafia, such as Quebec, and so having multiple roadway construction projects ongoing with no actual work done for months would actually be a frequent, intentional occurrence.
You don't know just from driving by whether 99.9% of projects are quick and efficient.