Calculate Total Traveled Distance iOS Swift

update: Xcode 8.3.2 • Swift 3.1

The problem there is because you are always getting the same location over and over again. Try like this:

import UIKit
import MapKit

class ViewController: UIViewController,  CLLocationManagerDelegate {
    @IBOutlet weak var mapView: MKMapView!
    let locationManager = CLLocationManager()
    var startLocation: CLLocation!
    var lastLocation: CLLocation!
    var startDate: Date!
    var traveledDistance: Double = 0
    override func viewDidLoad() {
        super.viewDidLoad()
        if CLLocationManager.locationServicesEnabled() {
            locationManager.delegate = self
            locationManager.desiredAccuracy = kCLLocationAccuracyBest
            locationManager.requestWhenInUseAuthorization()
            locationManager.startUpdatingLocation()
            locationManager.startMonitoringSignificantLocationChanges()
            locationManager.distanceFilter = 10
            mapView.showsUserLocation = true
            mapView.userTrackingMode = .follow
        }
    }
    func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
        if startDate == nil {
            startDate = Date()
        } else {
            print("elapsedTime:", String(format: "%.0fs", Date().timeIntervalSince(startDate)))
        }
        if startLocation == nil {
            startLocation = locations.first
        } else if let location = locations.last {
            traveledDistance += lastLocation.distance(from: location)
            print("Traveled Distance:",  traveledDistance)
            print("Straight Distance:", startLocation.distance(from: locations.last!))
        }
        lastLocation = locations.last
    }
    func locationManager(_ manager: CLLocationManager, didFailWithError error: Error) {
        if (error as? CLError)?.code == .denied {
            manager.stopUpdatingLocation()
            manager.stopMonitoringSignificantLocationChanges()
        }
    }
}

Sample Project

If you want to calculate the route distance between two points you need to use MKDirectionsRequest, this will return you one, or many, routes from point A to point B with the step by step instruction:

class func caculateDistance(){
    var directionRequest = MKDirectionsRequest()
    var sourceCoord = CLLocationCoordinate2D(latitude: -36.7346287, longitude: 174.6991812)
    var destinationCoord = CLLocationCoordinate2D(latitude: -36.850587, longitude: 174.7391745)
    var mkPlacemarkOrigen = MKPlacemark(coordinate: sourceCoord, addressDictionary: nil)
    var mkPlacemarkDestination = MKPlacemark(coordinate: destinationCoord, addressDictionary: nil)
    var source:MKMapItem = MKMapItem(placemark: mkPlacemarkOrigen)
    var destination:MKMapItem = MKMapItem(placemark: mkPlacemarkDestination)
    directionRequest.setSource(source)
    directionRequest.setDestination(destination)
    var directions = MKDirections(request: directionRequest)
    directions.calculateDirectionsWithCompletionHandler {
        (response, error) -> Void in
        if error != nil { println("Error calculating direction - \(error.localizedDescription)") }
        else {
            for route in response.routes{
                println("Distance = \(route.distance)")
                for step in route.steps!{
                    println(step.instructions)
                }  
            }
        }
    }
}

This example code will return you this:

Distance
Distance = 16800.0

Step by Step instructions
Start on the route
At the end of the road, turn left onto Bush Road
Turn right onto Albany Expressway
At the roundabout, take the first exit onto Greville Road toward 1, Auckland
At the roundabout, take the third exit to merge onto 1 toward Auckland
Keep left
Take exit 423 onto Shelly Beach Road
Continue onto Shelly Beach Road
At the end of the road, turn right onto Jervois Road
Turn left onto Islington Street
Keep right on Islington Street
Arrive at the destination

The function can be easily modified to receive two locations and return the distance and any other needed information.

I hope that helps you!

Leo Dabus method could be used to calculate the geographical distance between your actual location and start one.

In order to obtain the precise traveled distance, you have to update "traveledDistance" using the difference between the last position and the old one.

This is my implementation:

var startLocation:CLLocation!
var lastLocation: CLLocation!
var traveledDistance:Double = 0

func locationManager(manager: CLLocationManager!, didUpdateLocations locations: [AnyObject]!) {
    if startLocation == nil {
        startLocation = locations.first as! CLLocation
    } else {
        let lastLocation = locations.last as! CLLocation
        let distance = startLocation.distanceFromLocation(lastLocation)
        startLocation = lastLocation
        traveledDistance += distance 
    }
}