It's pretty clear that most requests for chicanes are coming from community councils and/or neighbourhood partnerships.
If you really want to do something about this, I suggest you join your local CC or offer to attend NP transport meetings on behalf of Spokes or Living Streets.
Lionfishy represented Spokes on the SWNP transport committee, which is probably responsible for the Balgreen chicane. Don't know if someone else is attending now or not.
Too late to get these removed, but you might be able to prevent more.
I suggested this in the autumn, when CC's had elections, but there are probably still spaces if you contact them and indicate your interest.