Equipping pedestrian street crossings with acoustic and tactile signals to help disabled persons was a step forward. The problem is that they vary from one country to another. Now, a new ISO standard provides the basis for harmonizing such signals on a worldwide basis.
The aim of ISO 23600:2007, Assistive products for persons with vision impairments and persons with vision and hearing impairments – Acoustic and tactile signals for pedestrian traffic lights is to ensure equivalent information worldwide at intersections equipped with pedestrian crossing signals.
Read more at "New ISO Standard will make crossing the street safer for disabled persons" (.pdf)