Hong Kong cabbies who don't speak English have a simple solution to the problem of passengers who don't speak Cantonese - they use their cell phone to call someone who does speak English, hands the phone over to the passenger who can then tell the dual-language colleague their desired destination. The translator signals success with an 'OK, please hand phone back to driver', who, upon getting the phone gets the destination recited back to them, but now in Cantonese. I had this happen to me a couple of times this last week.
The other model I availed myself of is "pre-emptive translation", get an English/Cantonese speaking doorman or concierge to write out the destination, and then present this 'token' to the driver when getting into the cab.
In a city where any given cabbie might speak any of a number of languages (like Ottawa), the second model would suffer as it implies the translation service (the doorman) is able to anticipate the necessary "token format". Maybe cabbies could advertise their language capabilities metadata on a flag above their ride so that the translation service wouldn't have to guess.
Of course, it's easiest if everybody just speaks Canadian English eh.
Speaking of translation assistance, somebody obviously had to have helped with this. The polite beginning was a giveaway.