The positives for me here are that it seems that some operational traffic officers have decided that something needs to be done and they are doing it. They are occasionally managing to get some wider publicity, and concern that close overtaking may lead to police action including prosecution may spill over into other areas. Not everybody by any means is aware of different police areas so they may still be influenced if they never go near Brum. Also, this hasn't been a one-off "clampdown" AKA media stunt but has continued long-term, even if they can't be doing it every day.
One year's results cannot be conclusive, partly because there's no data on other things like the level of cycling during the year, but a casualty reduction is still welcome in itself. A more accurate comparison might be to analyse close passing crashes. Crashes at junctions will not be directly influenced, although the knowledge that the police are active in respect of cyclists' safety might have an useful indirect effect. If it continues another year, we'll have a better set of stats and it will reflect even more police commitment.
On the main thread I posted that it would be useful to hear from any local riders about whether they feel any difference. Is the typical driver in Brum giving riders more room? Subjective, anecdotal, but a few happy riders would impress me more than a lot of stats.
The negative for me is that a lot of mats were bought through the generosity of crowd-funders and we get few reports of their being rolled out.
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edit to remeve an embarrassing typo