Geolocation directs to building entrance and not defined LatLng - google-maps

Question

I am currently adapting and cleaning up a very simple Google Maps application for users to get walking directions from their current location (determined by GeoLocation) to preset markers designating artworks that are defined with specific LatLng values to the sixth decimal.
There is still a lot of extraneous code in the example that needs to be removed, but the core function is working as expected - almost.
When the user selects a destination from the values supplied in a dropdown menu and hits enter, a lined path appears from where they are to the selected destination - using the calcRoute function.
However, the path is consistently directing the user to the nearest building entrance - which in some cases is several hundred feet away from the LatLng defined in the code. This does not appear to be random inaccuracy, as the path always ends at a building entrance.
I am sure this is a very simple mistake I am making, but I haven't found any posts that seem to address this odd behavior.
I am using Windows 8 and Chrome at the moment for the base development in an attempt to get a working version and then test on other browsers. I appreciate any advice, and will supply all the example code if needed. Here is a sample of some of the typical lines in this app:
<script src="https://maps.googleapis.com/maps/api/js?v=3.exp&signed_in=true">
</script>
<script>
var locTreeWrapIII = new google.maps.LatLng(48.006640, -122.203680);
</script>
// Tree Wrap III
var markerTreeWrapIII = new google.maps.Marker({
map: map,
position: locTreeWrapIII,
title: 'Tree Wrap III'
});
var infoTreeWrapIII = new google.maps.InfoWindow({ // info window
maxWidth: 400,
content:
'<img alt="" src="https:\/thumbnail-clothespins.jpg" />' +
'<strong>' + markerTreeWrapIII.title + '<\/strong><br \/><br \/><br \/>
Read more about Tree Wrap III'
});
google.maps.event.addListener(markerTreeWrapIII, "click", function () {
document.getElementById('end').value = "(48.006500,-122.203500)";
infoTreeWrapIII.open(map, markerTreeWrapIII);
infoTreeWrapIII.setZIndex(999);
});
google.maps.event.addListener(markerTreeWrapIII, "dblclick", function () {
map.panTo(locTreeWrapIII);
});
google.maps.event.addListener(infoTreeWrapIII, "closeclick", function () {
infoTreeWrapIII.setZIndex(1);
infoTreeWrapIII.close();
});
function calcRoute() {
// Retrieve the start and end locations and create
// a DirectionsRequest using WALKING directions.
var start = document.getElementById('start').value;
var end = document.getElementById('end').value;
var request = {
origin: start,
destination: end,
travelMode: google.maps.TravelMode.WALKING
};
// Route the directions and pass the response to a
// function to create markers for each step.
directionsService.route(request, function (response, status) {
if (status == google.maps.DirectionsStatus.OK) {
directionsDisplay.setDirections(response);
}
});
}
function attachInstructionText(marker, text) {
google.maps.event.addListener(marker, 'click', function () {
// Open an info window when the marker is clicked on,
// containing the text of the step.
stepDisplay.setContent(text);
stepDisplay.open(map, marker);
});
}

Answer 1

My guess is that the WALKING travelling mode restricts paths to sidewalks, and thus to the entrances of buildings. Your code looks fine.
According to the API documentation:
walking requests walking directions via pedestrian paths & sidewalks (where available).
so it is very likely that Google has geocoded the the specific LatLng as an address, and is attempting to deliver the walker directly to that address.
A possible, though crude, solution would be to append a final LatLng to the path returned by the Directions Service that is the desired position.