Sorry for barging in like this and not participating earlier. Was extremely tied up.
I have been keenly following the thread, and lots of wild ideas have popped up. Here is my 2 cents, 1. Don't try to bring in high tech gadgets, the cost would kill project before it see day light. 2. Don't expect people to spend thousands on devices, India is poor country and need low cost solutions.
Lastly, here is my idea, Install small FM transmitter, covering a distance of 10-15 meter, at all the junction. These will radio a pre recorded message, giving name of square, direction to nearest land marks etc. The message will be continuously played. The transmitter will operate in FM band, so a simple FM radio will work.
This will not only helpful to handicapped, but people who are new to Mumbai, people driving at night and others.
And the cost, the transmitter will with pre recorded voice IC will cost 100-150, and user will need only FM radio.
Best Regards,
Mukund Deshmukh. Beta Computronics Pvt Ltd 10/1, IT Park, Parsodi, Nagpur-440022 Cell - 9422113746