Train Positions

Real-time train positions and support methods.

Track Circuits

Description

Returns a list of all track circuits including those on pocket tracks and crossovers. Each track circuit may include references to its right and left neighbors.

Please refer to this page for additional details.

Response Elements

Element Description
TrackCircuits Array containing track circuit information (TrackCircuit).
TrackCircuit Elements
CircuitId An internal system-wide uniquely identifiable circuit number.
Neighbors Array containing track circuit neighbor information (TrackCircuitNeighbor). Note that some track circuits have no neighbors in one direction. All track circuits have at least one neighbor.
Track Track number. 1 and 2 denote "main" lines, while 0 and 3 are connectors (between different types of tracks) and pocket tracks, respectively.
TrackCircuitNeighbor Elements
CircuitIds Array containing neighboring circuit ids.
NeighborType Left or Right neighbor group. Generally speaking, left neighbors are to the west and south, while right neighbors are to the east/north.

Neighbor Notes

Given the hypothetical example below, note that CircuitId 8 has two right neighbors - 4 and 3. Similarly, CircuitId 6 has two left neighbors - 5 and 7.

background Layer 1 Track 2 8 4 Track 1 CircuitId 1 2 CircuitId 4 9 100 3 Track 0 Track 0 Track 3 7 5 6

The JSON representation of the image above would be as follows:

{
"TrackCircuits": [{
"Track": 2,
"CircuitId": 8,
"Neighbors": [{
"NeighborType": "Right",
"CircuitIds": [4, 3]
}]
}, {
"Track": 2,
"CircuitId": 4,
"Neighbors": [{
"NeighborType": "Left",
"CircuitIds": [8]
}, {
"NeighborType": "Right",
"CircuitIds": [9]
}]
}, {
"Track": 2,
"CircuitId": 9,
"Neighbors": [{
"NeighborType": "Left",
"CircuitIds": [4]
}]
}, {
"Track": 0,
"CircuitId": 3,
"Neighbors": [{
"NeighborType": "Left",
"CircuitIds": [8]
}, {
"NeighborType": "Right",
"CircuitIds": [100]
}]
}, {
"Track": 3,
"CircuitId": 100,
"Neighbors": [{
"NeighborType": "Left",
"CircuitIds": [3]
}, {
"NeighborType": "Right",
"CircuitIds": [7]
}]
}, {
"Track": 0,
"CircuitId": 7,
"Neighbors": [{
"NeighborType": "Left",
"CircuitIds": [100]
}, {
"NeighborType": "Right",
"CircuitIds": [6]
}]
}, {
"Track": 1,
"CircuitId": 1,
"Neighbors": [{
"NeighborType": "Right",
"CircuitIds": [2]
}]
}, {
"Track": 1,
"CircuitId": 2,
"Neighbors": [{
"NeighborType": "Left",
"CircuitIds": [1]
}, {
"NeighborType": "Right",
"CircuitIds": [5]
}]
}, {
"Track": 1,
"CircuitId": 5,
"Neighbors": [{
"NeighborType": "Left",
"CircuitIds": [2]
}, {
"NeighborType": "Right",
"CircuitIds": [6]
}]
}, {
"Track": 1,
"CircuitId": 6,
"Neighbors": [{
"NeighborType": "Left",
"CircuitIds": [5, 7]
}]
}]
}

Try it

Request URL

Request parameters

string

Returns response in the specified format. Currently supported formats include json and xml.

Request headers

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

Request body

Code samples

@ECHO OFF

curl -v -X GET "https://api.wmata.com/TrainPositions/TrackCircuits?contentType={contentType}"
-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/TrainPositions/TrackCircuits?contentType={contentType}&" + 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/TrainPositions/TrackCircuits?contentType={contentType}");


            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/TrainPositions/TrackCircuits?contentType={contentType}&" + $.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/TrainPositions/TrackCircuits?contentType={contentType}";
    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/TrainPositions/TrackCircuits?contentType={contentType}');
$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", "/TrainPositions/TrackCircuits?contentType={contentType}&%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", "/TrainPositions/TrackCircuits?contentType={contentType}&%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/TrainPositions/TrackCircuits?contentType={contentType}')

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