I created a real time map for Boston: <a href="http:&#x2F;&#x2F;bostontraintrack.com" rel="nofollow">http:&#x2F;&#x2F;bostontraintrack.com</a> .<p>It uses live data but it doesn&#x27;t interpolate position.  It updates about every 15-20s or so.  Source is available (and FOSS) [1].<p>[1] <a href="https:&#x2F;&#x2F;github.com&#x2F;abetusk&#x2F;bostontraintrack" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;abetusk&#x2F;bostontraintrack</a>