Add a traffic layer to maps in Flexible Map; specify an ID so that the code can match the map requiring traffic layer. e.g. `[flexiblemap address="Wickham train station, Wickham NSW Australia" width="100%" region="au" id="with_traffic"]`

flxmap-traffic-layer.php

<?php
/*
Plugin Name: Flxmap Traffic Layer example
Plugin URI: https://gist.github.com/webaware/3393b3ec78af8b302135bfb1d4956dd8
Description: add a traffic layer to map that has id="with_traffic"
Version: 1
Author: WebAware
Author URI: http://webaware.com.au/
*/

if (!defined('ABSPATH')) {
    exit;
}

add_action('wp_enqueue_scripts', function() {
    wp_enqueue_script('jquery');
});

add_action('wp_footer', function() {
?>

<script>
jQuery(window).load(function($) {
    if ("flxmap_with_traffic" in window) {
        var map = flxmap_with_traffic.getMap();
        var trafficLayer = new google.maps.TrafficLayer();
        trafficLayer.setMap(map);
    }
});
</script>

<?php
});