we have an element of infrastructure in bham, but even that isn't enough.
my feeling is driver instinct and empathy needs addressing. one main reason I cycle is the amount of queues everywhere, and it terrifies me the volume of people I see on their phones, and also people driving and they're so switched off as to what is around them all the time. even though I am on a bike, I am repeatedly cut up, especially on corners. I also never cease to be amazed how impatient many drivers are/can be, and their desperation to overtake me, frequently that's done un-safely.
@Keef has also mentioned the prevalence of broken glass too, and the volume of that seems to be increasing. There is a cycle lane by my place of work, and to be honest it is exceptionally busy (bikes and also e scooters), but even the cycle lane is full of glass - there was so much yesterday I had to come out of it, and I couldn't help but feel it had been done on purpose.