output

Processing feeds from NY
JSON error: No error

Processing feeds from MD
JSON error: Syntax error

test.php

<?php
function eol ($str = '')
{
    return $str . PHP_EOL;
}

$feeds = [
    "NY" => "https://gist.githubusercontent.com/kuanb/dbe19ce4e8ef317ee3fc/raw/8dd002cc26f7076eed84f0104bbc70eb1117b9f9/traffic-cameras.json",
    'MD' => "https://gist.githubusercontent.com/alexwpotter/e222e644018e696ba8b60d35d285776a/raw/fa8866386c9e36f23a2153ea6e87e9b001d36c35/MDtraffic.json"
];

foreach ($feeds as $key => $feed) {
    echo eol('Processing feeds from '. $key);
    $str = file_get_contents($feed);

    json_decode($str, true);
    echo eol('JSON error: ' . json_last_error_msg());
    echo eol();
}