How do I change the car icon to truck icon..

I tried this,but head position are not to rotate that road position ..Can you please guide this
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//window.onload = calcRoute;



var step = 50; // 5; // metres
var tick = 1000; // milliseconds
var eol;
var k = 0;
var stepnum = 0;
var speed = "";
var lastVertex = 1;

//=============== animation functions ======================
function updatePoly(d) {
// Spawn a new polyline every 20 vertices, because updating a 100-vertex poly is too slow
if (poly2.getPath().getLength() > 20) {
poly2 = new google.maps.Polyline([polyline.getPath().getAt(lastVertex - 1)]);
// map.addOverlay(poly2)
}

if (polyline.GetIndexAtDistance(d) < lastVertex + 2) {
if (poly2.getPath().getLength() > 1) {
poly2.getPath().removeAt(poly2.getPath().getLength() - 1);
}
poly2.getPath().insertAt(poly2.getPath().getLength(), polyline.GetPointAtDistance(d));
} else {
poly2.getPath().insertAt(poly2.getPath().getLength(), endLocation.latlng);
}
}

function animate(d) {
if (d > eol) {
map.panTo(endLocation.latlng);
marker.setPosition(endLocation.latlng);
return;
}
var p = polyline.GetPointAtDistance(d);
map.panTo(p);
var lastPosn = marker.getPosition();
marker.setPosition(p);
var heading = google.maps.geometry.spherical.computeHeading(lastPosn, p);
icon.rotation = heading;
marker.setIcon(icon);
updatePoly(d);
timerHandle = setTimeout("animate(" + (d + step) + ")", tick);
}

function startAnimation() {
eol = polyline.Distance();
map.setCenter(polyline.getPath().getAt(0));
marker = new google.maps.Marker({
position: polyline.getPath().getAt(0),
map: map,
icon: icon
});

poly2 = new google.maps.Polyline({
path: [polyline.getPath().getAt(0)],
strokeColor: "#0000FF",
strokeWeight: 10
});
// map.addOverlay(poly2);
setTimeout("animate(10)", 2000); // Allow time for the initial map display
}
google.maps.event.addDomListener(window, 'load');

//=============== ~animation funcitons =====================


var icon = {
url: "http://www.geocodezip.com/mapIcons/SO_20170925_multiplePaths_mod.svg",
anchor: new google.maps.Point(39, 60),
scale: .7,
strokeColor: 'white',
strokeWeight: .10,
fillOpacity: 1,
fillColor: '#0000FF',
offset: '5%',
size: new google.maps.Size(120, 120)
};

//var car = "M17.402,0H5.643C2.526,0,0,3.467,0,6.584v34.804c0,3.116,2.526,5.644,5.643,5.644h11.759c3.116,0,5.644-2.527,5.644-5.644 V6.584C23.044,3.467,20.518,0,17.402,0z M22.057,14.188v11.665l-2.729,0.351v-4.806L22.057,14.188z M20.625,10.773 c-1.016,3.9-2.219,8.51-2.219,8.51H4.638l-2.222-8.51C2.417,10.773,11.3,7.755,20.625,10.773z M3.748,21.713v4.492l-2.73-0.349 V14.502L3.748,21.713z M1.018,37.938V27.579l2.73,0.343v8.196L1.018,37.938z M2.575,40.882l2.218-3.336h13.771l2.219,3.336H2.575z M19.328,35.805v-7.872l2.729-0.355v10.048L19.328,35.805z";
//var icon = {
// path: car,
// scale: .7,
// strokeColor: 'white',
// strokeWeight: .10,
// fillOpacity: 1,
// fillColor: '#0000FF',
// offset: '5%',
// rotation: parseInt(heading[i]),
// anchor: new google.maps.Point(10, 25) // orig 10,50 back of car, 10,0 front of car, 10,25 center of car
//};

// === first support methods that don't (yet) exist in v3
google.maps.LatLng.prototype.distanceFrom = function (newLatLng) {
var EarthRadiusMeters = 6378137.0; // meters
var lat1 = this.lat();
var lon1 = this.lng();
var lat2 = newLatLng.lat();
var lon2 = newLatLng.lng();
var dLat = (lat2 - lat1) * Math.PI / 180;
var dLon = (lon2 - lon1) * Math.PI / 180;
var a = Math.sin(dLat / 2) * Math.sin(dLat / 2) + Math.cos(lat1 * Math.PI / 180) * Math.cos(lat2 * Math.PI /

ya okay fine thank you...