Hearing Impaired Roadside Assistance Number?

While waiting for my parents, I decided to look at a roadmap to pass the time. When I looked at the backside of the map, I noticed two phone numbers, and one of the numbers was for the hearing impared to call. Now I’m wondering how do the deaf interact with the phone call, and what the roadside assistance does for them on the phone.

Deaf people use TTYs, which are machines that are kind of like typewriters. You type in it, and the message is relayed to another TTY. If you want to talk to a hearing person on a regular phone, you go through a relay service:

you type; the relay person reads what you type and speaks to the person; the person speaks to the relay; the relay types it back on a TTY.

I’m not sure about roadside assistance, but I would guess most Deaf people now carry around a cell-phone with text messaging capabilities.

A TTY number just means that a TTY answers it. Instead of voice.