Compare highway and avoid highway distance

Question

I would like to compare distance when using highway and when avoiding highway but I have no idea how to do it. My code is calculating distance between two points and the price based on distance. If highway checkbox is checked it should calculate different price but when there is no highway the price should remain the same.

This is the code

var directionsDisplay = new google.maps.DirectionsRenderer();
var directionsService = new google.maps.DirectionsService();
var map;

function initialize() {

  var myOptions = {
    center: new google.maps.LatLng(43.521573, 16.441015),
    zoom: 5,
    mapTypeID: google.maps.MapTypeId.ROADMAP
  };

  map = new google.maps.Map(document.getElementById('map-canvas'), myOptions);

  directionsDisplay.setMap(map);

  google.maps.event.trigger(map, 'resize');

}

function calcRoute() {
  var start = document.getElementById('start').value;
  var end = document.getElementById('end').value;
  var vehicle = document.getElementById('vehicle').value;

  //var highway = document.getElementById('highway').checked;
  //var round = document.getElementById('return').checked;

  var distanceInput = document.getElementById('distance');
  var timeInput = document.getElementById('time');
  var priceInput = document.getElementById('price');

  var request, price;

  if (document.getElementById('highway').checked) {
    request = {
      origin: start,
      destination: end,
      travelMode: google.maps.TravelMode.DRIVING,
      avoidHighways: false
    };

  } else {
     request = {
      origin: start,
      destination: end,
      travelMode: google.maps.TravelMode.DRIVING,
      avoidHighways: true
    };

  }

  directionsService.route(request, function(response, status) {
    if (status == google.maps.DirectionsStatus.OK) {

      directionsDisplay.setDirections(response);

      if (document.getElementById('highway').checked)
        dist_highway = response.routes[0].legs[0].distance.value / 1000;
      else
        dist = response.routes[0].legs[0].distance.value / 1000;

      distanceInput.value = response.routes[0].legs[0].distance.value / 1000;

      var hours = parseInt( response.routes[0].legs[0].duration.value / 3600) % 24;
      var minutes = parseInt( response.routes[0].legs[0].duration.value / 60) % 60;
      timeInput.value = hours + "h " + minutes + "m";


      if (vehicle == 'van') {
        if ((response.routes[0].legs[0].distance.value / 1000) < '30' ) {
          price = (response.routes[0].legs[0].distance.value / 1000) * 1.19;
        } else {
          price = (response.routes[0].legs[0].distance.value / 1000) * 0.93;
        }
      } else if (vehicle == 'personal') {
        if ((response.routes[0].legs[0].distance.value / 1000) < '30' ) {
          price = (response.routes[0].legs[0].distance.value / 1000) * 1.32;
        } else {
          price = (response.routes[0].legs[0].distance.value / 1000) * 1.06;
        }
      }

      if (document.getElementById('highway').checked && vehicle == 'personal' ) {
        price *= 1.3;
      } else if (document.getElementById('highway').checked && vehicle == 'van' ) {
        price *= 1.5;
      };

      if (document.getElementById('return').checked) {
        price *= 1.7;

      };

      priceInput.value = price.toFixed(2) + "€";

    }
  });
}


google.maps.event.addDomListener(window, 'load', initialize);

After AlexB's explanation this is my function. Problem solved.

function calcDist(start, end) {
  var requestHighway, request, distHighway, dist;
  var dirService = new google.maps.DirectionsService();

  requestHighway = {
      origin: start,
      destination: end,
      travelMode: google.maps.TravelMode.DRIVING,
      avoidHighways: false
    };

  request = {
      origin: start,
      destination: end,
      travelMode: google.maps.TravelMode.DRIVING,
      avoidHighways: true
    };

  dirService.route(requestHighway, function(response, status) {

    if (status == google.maps.DirectionsStatus.OK) {

      distHighway = response.routes[0].legs[0].distance.value / 1000;
      distHighway = distHighway.toFixed(2);

    }
  });

  dirService.route(request, function(response, status) {

    if (status == google.maps.DirectionsStatus.OK) {

      dist = response.routes[0].legs[0].distance.value / 1000;
      dist = distHighway.toFixed(2);

    }
  });

  if (distHighway - dist == 0) {
    return true;
  } else {
    return false;
  }

}

Answer 1

After AlexB's explanation this is my function. Problem solved.

function calcDist(start, end) {
  var requestHighway, request, distHighway, dist;
  var dirService = new google.maps.DirectionsService();

  requestHighway = {
      origin: start,
      destination: end,
      travelMode: google.maps.TravelMode.DRIVING,
      avoidHighways: false
    };

  request = {
      origin: start,
      destination: end,
      travelMode: google.maps.TravelMode.DRIVING,
      avoidHighways: true
    };

  dirService.route(requestHighway, function(response, status) {

    if (status == google.maps.DirectionsStatus.OK) {

      distHighway = response.routes[0].legs[0].distance.value / 1000;
      distHighway = distHighway.toFixed(2);

    }
  });

  dirService.route(request, function(response, status) {

    if (status == google.maps.DirectionsStatus.OK) {

      dist = response.routes[0].legs[0].distance.value / 1000;
      dist = distHighway.toFixed(2);

    }
  });

  if (distHighway - dist == 0) {
    return true;
  } else {
    return false;
  }

}