But there's no accounting for half-wits who think they are invulnerable

Sadly that also applies to pedestrians. I am amazed by the number of pedestrians that walk along the road with dark clothing. This time of year the contrast between bright sunlight and trees shading the road means that pedestrians in dark clothing tend to merge into the shadows.
Many of the roads where I am are really 1.5 lanes wide with no pavements. Tractors, cyclists, pedestrians, trucks all share the same restricted space and with oncoming traffic all make for whatever verge may exist. Sharp eyes,patience and slow/moderate speed is a necessity.