MBTA Real-Time Subway Predictions

This script converts the MBTA's real-time subway data into a JSON feed.

This script was written for the Open Civic Data project.

Demonstration Feed

Predictions:

• http://openmbta.org/ocd/subway_predictions.json

To estimate train positions:

• http://openmbta.org/ocd/train_locations.json

Usage

ruby geo_subway_stops.rb
ruby polylines.rb

ruby subway_predictions.rb  
ruby train_locations.rb

Run the latter two on cron every x minutes.

Predictions Response Format

[
  {
    "line": "Red",
    "trips": [
      {
        "trip_id": 95,
        "predictions": [
          {
            "name": "Quincy Adams Station",
            "status": "Arrived",
            "time": "2011-02-26T16:23:59+00:00",
            "type": "Revenue",
            "route": "Braintree Branch"
          },
          {
            "name": "Braintree Station",
            "status": "Predicted",
            "time": "2011-02-26T16:28:00+00:00",
            "type": "Revenue",
            "route": "Braintree Branch"
          }
        ]
      }, ...
    ]
  },
  {
    "line": "Blue",
    "trips": [
      {
        "trip_id": 112,
        "predictions": [
          {
            "name": "Bowdoin Station",
            "status": "Arrived",
            "time": "2011-02-26T16:19:51+00:00",
            "type": "Revenue",
            "route": "0"
          }
        ]
      },
    ...

Locations Response Format

{
  "Red": [
    {
      "left": {
        "name": "Quincy Adams Station",
        "time": "2011-02-26 13:32:39 -0500",
        "geo": [
          -71.006839,
          42.23334
        ]
      },
      "arriving": {
        "name": "Braintree Station",
        "time": "2011-02-26 13:36:53 -0500",
        "geo": [
          -71.001601,
          42.207411
        ]
      }
    },

References

http://www.eot.state.ma.us/developers/

http://developer.mbta.com/RT_Archive/DataExplained.txt

http://developer.mbta.com/RT_Archive/RealTimeHeavyRailKeys.csv