Pedestrian crossings which take so long between pressing the button and the lights actually changing that runners (and other pedestrians) take their chances dodging the cars instead of waiting for the lights to change.
Badly maintained pavements - great for tripping up on, particularly when having to swerve to avoid oblivious pedestrian (see below).
[Possible solution for crossing roads: provide more islands in the centres of roads so runners and other pedestrians can cross one side at a time.]
The other main problems are to do with human behaviour:
- Car drivers not bothering to look before turning into side roads.
- Car drivers who obviously don't think runners count as pedestrians, when on zebra crossings (as in, if you're a runner, they don't need to stop for you to cross).
- People walking two/three/four/ abreast (depending on width of pavement) with absolutely no consideration for/wareness of other people (walking or running) wanting to get past in either direction, then getting surprised/annoyed when you brush past them.
- People walking with dog on flexi lead with dog on one side of the pavement and person on the other side, producing a tripwire.
- People walking (or cycling!) with their earphones in, while texting, and wandering all over the pavement. Ditto talking on mobile phone - proving that most people really can't walk and talk at the same time...
I could go on, but it gets depressing.