> Anyone can read a number? Hardly. A huge number of people would have trouble getting all the digits, precisely and in order without mistakes.
You only need 3 decimal places for ~100m accuracy. So really you're talking a 5 digit number and a 4 digit number (in the UK). A sensible presentation of that data would not be hard to read for almost anyone who doesn't have sight problems.
Moreover, a service like the theoretical "999.gov.uk" could log a person's GPS location and give them (say) a three word codephrase to pass to the dispatcher to lookup the record on the backend. No more or less effort, but not proprietary and harder to mess up.
> Also, words have audio redundancy. If I say "apple" you get the same data as if I say "a_ple" or "_pple" or "app_e" or if you don't, you know there was a glitch and can ask for retransmission.
This is true. I don't think there's a good way to fix that with numbers.