This utility saves money for those who use a feature phone to access the NextBus service for bus predictions via text message.
With the standard system, each prediction costs at least two text messages: one to NextBus, and one for the reply.
If multiple bus routes serve a stop, even more text messages are required:
- me: Tell me the predictions for stop 8819
- NextBus: Do you want route 70 or 70A?
- me: 70
- NextBus: buses arrive in 7, 30, and 50 minutes.
Cost: Four text messages. Plus I don't get predictions for route 70A, which would also work for me.
NextBus does allow you to save a query for future use (saving us question 2 for the specific route), but the minimum interaction still requires two text messages.
- costs one text message per query
- provides predictions for more than one route
- sends the prediction via email or text message (which is cheaper for you?)
- pre-registration of your routes is required (no ad-hoc queries)
- the service currently runs on a free Heroku dyno; your response may be delayed while the application wakes.
[ Seven of Nine says: "elaborate" ]
- call from any phone (probably a feature phone)
- Google Voice receives call, sends "missed call" email
- CloudMailin translates the email into a POST request
- Sinatra application looks up phone number, finds user's bus stops
- query NextBus for arrival predictions
- based on user's notification preference:
- send predictions via email ( Mandrill/MailChimp )
- send predictions via text message ( Amazon Simple Notification Service )
- [ evaluate: SNS can do both email and text message, plus HTTP & SQS. Perhaps use it for all notifications? ]
- schedule a query for a particular time (instead of calling)