AJAX call to make an HTTP request
Since the HTTP response implements Writable Stream and Express wraps around HTTP, you can pipe the output to the response, like so:

app.get('/getTime', function(req, res) {
    var url = 'http://www.ctabustracker.com/bustime/api/v1/gettime';

    http.get(url + '?key=' + apikey, function(incoming) {
        incoming.pipe(res);
    }
});


It will not only cut down on latency times but also cut down on lines of code.