I think the programming for the nav unit is limited in its abilities. They didn't even put conditional code in how the voice "reads" major highway names;
When it wants me to travel on I95 North, it will literally say: "STAY... ON... EYE... NINETY-FIVE... NORTH". We all understand that the word pronounced "EYE" is the letter "I", which is the initial for "Interstate".
But when it wants me to travel on Route 1 North, it says: "STAY... ON... ARE... TEE... ONE... NORTH". The "ARE TEE ONE" is Rt.1 phonetically spoken, but they could have easily programmed it to know that the word "Route" or any variant abbreviation should be pronounced as "Route" - not "ARE TEE".
That leads me to believe that it does not have text-to-speech abilities and that it would NOT be able to pull a road or street name from the data and announce it verbally.
At best (and this is just a guess) it would only be able to say: "TAKE... A... RIGHT... ONTO... EMM... AYY... EYE... ENN... STREET" For Main Street. Imagine if the road was (and IS in my area) Massachusetts Avenue?
"TAKE.. A... RIGHT... ONTO... EMM... AYY... ESS... ESS... AYY... SEA... AYCH... YOU... ESS... EEE... TEE... TEE... ESS... Ave..."
By the time it's done spelling, you're 1/4-Mile past Mass Ave.