Real-Time Rail Predictions

Real-time rail prediction methods.

JSON - Next Trains

Description

Returns next train arrival information for one or more stations. Will return an empty set of results when no predictions are available. Use All for the StationCodes parameter to return predictions for all stations.

For terminal stations (e.g.: Greenbelt, Shady Grove, etc.), predictions may be displayed twice.

Some stations have two platforms (e.g.: Gallery Place, Fort Totten, L'Enfant Plaza, and Metro Center). To retrieve complete predictions for these stations, be sure to pass in both StationCodes.

For trains with no passengers, the DestinationName will be No Passenger.

Next train arrival information is refreshed once every 20 to 30 seconds approximately.

Response Elements

Element Description
Trains Array containing train prediction information (AIMPredictionTrainInfo).
AIMPredictionTrainInfo Elements
Car Number of cars on a train, usually 6 or 8, but might also return - or NULL.
Destination Abbreviated version of the final destination for a train. This is similar to what is displayed on the signs at stations.
DestinationCode Destination station code. Can be NULL. Use this value in other rail-related APIs to retrieve data about a station.
DestinationName When DestinationCode is populated, this is the full name of the destination station, as shown on the WMATA website.
Group Denotes the track this train is on, but does not necessarily equate to Track 1 or Track 2. With the exception of terminal stations, predictions at the same station with different Group values refer to trains on different tracks.
Line Two-letter abbreviation for the line (e.g.: RD, BL, YL, OR, GR, or SV). May also be blank or No for trains with no passengers.
LocationCode Station code for where the train is arriving. Useful when passing in All as the StationCodes parameter. Use this value in other rail-related APIs to retrieve data about a station.
LocationName Full name of the station where the train is arriving. Useful when passing in All as the StationCodes parameter.
Min Minutes until arrival. Can be a numeric value, ARR (arriving), BRD (boarding), ---, or empty.

Try it

Request URL

Request parameters

string

Comma-separated list of station codes. For all predictions, use "All".

Request headers

string
Subscription key which provides access to this API. Found in your Profile.

Request body

Response 200

Default return code.

{"Trains":[{"Car":"6","Destination":"SilvrSpg","DestinationCode":"B08","DestinationName":"Silver Spring","Group":"1","Line":"RD","LocationCode":"A01","LocationName":"Metro Center","Min":"3"},{"Car":"6","Destination":"Grsvnor","DestinationCode":"A11","DestinationName":"Grosvenor-Strathmore","Group":"2","Line":"RD","LocationCode":"A01","LocationName":"Metro Center","Min":"4"},{"Car":"6","Destination":"Shady Gr","DestinationCode":"A15","DestinationName":"Shady Grove","Group":"2","Line":"RD","LocationCode":"A01","LocationName":"Metro Center","Min":"6"},{"Car":"8","Destination":"Glenmont","DestinationCode":"B11","DestinationName":"Glenmont","Group":"1","Line":"RD","LocationCode":"A01","LocationName":"Metro Center","Min":"8"},{"Car":"6","Destination":"SilvrSpg","DestinationCode":"B08","DestinationName":"Silver Spring","Group":"1","Line":"RD","LocationCode":"A01","LocationName":"Metro Center","Min":"9"},{"Car":"6","Destination":"Grsvnor","DestinationCode":"A11","DestinationName":"Grosvenor-Strathmore","Group":"2","Line":"RD","LocationCode":"A01","LocationName":"Metro Center","Min":"9"}]}

Code samples

@ECHO OFF

curl -v -X GET "https://api.wmata.com/StationPrediction.svc/json/GetPrediction/{StationCodes}"
-H "api_key: {subscription key}"

--data-ascii "{body}" 

using System;
using System.Net.Http.Headers;
using System.Text;
using System.Net.Http;
using System.Web;

namespace CSHttpClientSample
{
    static class Program
    {
        static void Main()
        {
            MakeRequest();
            Console.WriteLine("Hit ENTER to exit...");
            Console.ReadLine();
        }
        
        static async void MakeRequest()
        {
            var client = new HttpClient();
            var queryString = HttpUtility.ParseQueryString(string.Empty);

            // Request headers
            client.DefaultRequestHeaders.Add("api_key", "{subscription key}");

            var uri = "https://api.wmata.com/StationPrediction.svc/json/GetPrediction/{StationCodes}?" + queryString;

            var response = await client.GetAsync(uri);
        }
    }
}	
// // This sample uses the Apache HTTP client from HTTP Components (http://hc.apache.org/httpcomponents-client-ga/)
import java.net.URI;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.utils.URIBuilder;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;

public class JavaSample 
{
    public static void main(String[] args) 
    {
        HttpClient httpclient = HttpClients.createDefault();

        try
        {
            URIBuilder builder = new URIBuilder("https://api.wmata.com/StationPrediction.svc/json/GetPrediction/{StationCodes}");


            URI uri = builder.build();
            HttpGet request = new HttpGet(uri);
            request.setHeader("api_key", "{subscription key}");


            // Request body
            StringEntity reqEntity = new StringEntity("{body}");
            request.setEntity(reqEntity);

            HttpResponse response = httpclient.execute(request);
            HttpEntity entity = response.getEntity();

            if (entity != null) 
            {
                System.out.println(EntityUtils.toString(entity));
            }
        }
        catch (Exception e)
        {
            System.out.println(e.getMessage());
        }
    }
}


<!DOCTYPE html>
<html>
<head>
    <title>JSSample</title>
    <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.9.0/jquery.min.js"></script>
</head>
<body>

<script type="text/javascript">
    $(function() {
        var params = {
            "api_key": "{subscription key}",
            // Request parameters
        };
      
        $.ajax({
            url: "https://api.wmata.com/StationPrediction.svc/json/GetPrediction/{StationCodes}?" + $.param(params),
            type: "GET",
        })
        .done(function(data) {
            alert("success");
        })
        .fail(function() {
            alert("error");
        });
    });
</script>
</body>
</html>

#import <Foundation/Foundation.h>

int main(int argc, const char * argv[])
{
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
    
    NSString* path = @"https://api.wmata.com/StationPrediction.svc/json/GetPrediction/{StationCodes}";
    NSArray* array = @[
                         // Request parameters
                         @"entities=true",
                      ];
    
    NSString* string = [array componentsJoinedByString:@"&"];
    path = [path stringByAppendingFormat:@"?%@", string];

    NSLog(@"%@", path);

    NSMutableURLRequest* _request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:path]];
    [_request setHTTPMethod:@"GET"];
    // Request headers
    [_request setValue:@"{subscription key}" forHTTPHeaderField:@"api_key"];
    // Request body
    [_request setHTTPBody:[@"{body}" dataUsingEncoding:NSUTF8StringEncoding]];
    
    NSURLResponse *response = nil;
    NSError *error = nil;
    NSData* _connectionData = [NSURLConnection sendSynchronousRequest:_request returningResponse:&response error:&error];

    if (nil != error)
    {
        NSLog(@"Error: %@", error);
    }
    else
    {
        NSError* error = nil;
        NSMutableDictionary* json = nil;
        NSString* dataString = [[NSString alloc] initWithData:_connectionData encoding:NSUTF8StringEncoding];
        NSLog(@"%@", dataString);
        
        if (nil != _connectionData)
        {
            json = [NSJSONSerialization JSONObjectWithData:_connectionData options:NSJSONReadingMutableContainers error:&error];
        }
        
        if (error || !json)
        {
            NSLog(@"Could not parse loaded json with error:%@", error);
        }
        
        NSLog(@"%@", json);
        _connectionData = nil;
    }
    
    [pool drain];

    return 0;
}

<?php
// This sample uses the Apache HTTP client from HTTP Components (http://hc.apache.org/httpcomponents-client-ga/)
require_once 'HTTP/Request2.php';

$request = new Http_Request2('https://api.wmata.com/StationPrediction.svc/json/GetPrediction/{StationCodes}');
$url = $request->getUrl();

$headers = array(
    // Request headers
    'api_key' => '{subscription key}',
);

$request->setHeader($headers);

$parameters = array(
    // Request parameters
);

$url->setQueryVariables($parameters);

$request->setMethod(HTTP_Request2::METHOD_GET);

// Request body
$request->setBody("{body}");

try
{
    $response = $request->send();
    echo $response->getBody();
}
catch (HttpException $ex)
{
    echo $ex;
}

?>
########### Python 2.7 #############
import httplib, urllib, base64

headers = {
    # Request headers
    'api_key': '{subscription key}',
}

params = urllib.urlencode({
})

try:
    conn = httplib.HTTPSConnection('api.wmata.com')
    conn.request("GET", "/StationPrediction.svc/json/GetPrediction/{StationCodes}?%s" % params, "{body}", headers)
    response = conn.getresponse()
    data = response.read()
    print(data)
    conn.close()
except Exception as e:
    print("[Errno {0}] {1}".format(e.errno, e.strerror))

####################################

########### Python 3.2 #############
import http.client, urllib.request, urllib.parse, urllib.error, base64

headers = {
    # Request headers
    'api_key': '{subscription key}',
}

params = urllib.parse.urlencode({
})

try:
    conn = http.client.HTTPSConnection('api.wmata.com')
    conn.request("GET", "/StationPrediction.svc/json/GetPrediction/{StationCodes}?%s" % params, "{body}", headers)
    response = conn.getresponse()
    data = response.read()
    print(data)
    conn.close()
except Exception as e:
    print("[Errno {0}] {1}".format(e.errno, e.strerror))

####################################
require 'net/http'

uri = URI('https://api.wmata.com/StationPrediction.svc/json/GetPrediction/{StationCodes}')

request = Net::HTTP::Get.new(uri.request_uri)
# Request headers
request['api_key'] = '{subscription key}'
# Request body
request.body = "{body}"

response = Net::HTTP.start(uri.host, uri.port, :use_ssl => uri.scheme == 'https') do |http|
    http.request(request)
end

puts response.body