accessibility - How do blind people know where to find Braille signs?

On many occasions I have seen signs, with the equivalent in Braille underneath the text. Which is great. But what baffles me is this: how do blind people know where to find the Braille text?

I don't have any photo examples right now, but in one example I was on a train and noticed a sign on the window saying "Emergency exit, break glass". Underneath that was the Braille for "Emergency exit" (note, no actual instructions). And I couldn't help but wonder, in order to be read a blind person needs to run a finger across it, but why would they run their finger across a random part of the window?

Answer

I believe its because there are universally defined standards on where Braille letters have to positioned with regards to a informational item and braille users generally learn to look for them in one location. There are also classes conducted for people with visual disabilities which inform them where to look for the sign (the class is called Orientation and Mobility) .

The ISO (International Standards Organization) makes placement of signs in the public venue universal, no matter what country one is in. The requirement for signs are:

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  If placed on a door, the sign is to be in the center of the door with the centerline of the sign 5 feet from the floor. The Braille characters are to be at the bottom center of the sign. The writing on the sign is to be of contrasting color to the background.

  
  


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  If not placed on the door, the sign is to be placed to the right of the doorway, with the same requirements as to a sign placed on the door.

  
  

Here is an image which shows the positioning of the braille signs as per regulations from this site which sells braille signs.

To quote the article

Option 1

This is the preferred position of all Braille Tactile Signs. Position the Braille Signs leading edge between 50mm & 300mm from the architrave. Heightwise the Braille Sign must be positioned between 1200mm & 1600mm from the floor surface.

Option 2

The sign is to be centred on the door when option 1 is not possible.Heightwise, the Braille Tactile sign must be positioned between 1200mm & 1600mm from the floor surface.

The exact ISO specification is the ISO 17049:2013 which stands for Accessible design -- Application of braille on signage, equipment and appliances (Note : you will need to have a subscription to read it).