Healthy, and wearing sensible shoes, I have already twisted a foot on them. An acquaintance has sprained her ankle. It can only be a matter of time before someone has a serious fall and injures herself.
A quick canvass of other professionals in the field of disability has found that people with walking difficulties are at risk of tripping, and people with arthritis find them excruciatingly painful. Old people are walking in the road and crossing in dangerous places to avoid them.
Having trained blind people to travel for over 20 years, I am naturally all in favour of marking crossing points - not, however, at the cost of risking the safety of everybody else.
It is not necessary to go to such unpleasant lengths. Most of the thousand or so blind people I have taught can detect quite minor changes of surface.