[tsigel]

...
resultTripMethod: function(){
   viewRoude(directionService, directionRenderer, this.from, this.to, function (result) {
      console.log(result)
   }.bind(this));
}
...

function viewRoude(directionService, directionRenderer, start, end, callback){
	var request = {
		origin: new google.maps.LatLng(start.pos.lat, start.pos.lng),
		destination: new google.maps.LatLng(end.pos.lat, end.pos.lng),
		travelMode: google.maps.TravelMode.DRIVING
	};
	directionService.route(request, function(result, status){
		if(status == google.maps.DirectionsStatus.OK){
			callback(result);
		}
	});
}

Может быть так?