In our case the lanes were in for quite a few years. As I mentioned, we cycled through a couple of city councils before enough of the politicians that had spearheaded the initiative were gone and the new ones could do a study without feeling like their reputations were on the line.

And I should note, for those who are downvoting me, that I'm simply describing what happened. I ride my bike, I like bike lanes, but if bike lanes get put in bad places then popular support for bike lanes in general is harmed. If you like bike lanes too then you should be advocating for them to be placed where it's optimal for bike lanes to exist, not to place them in every possible location regardless of utility.