Programmatically open Maps app in iOS 6

The best way to do it is to call new iOS 6 method on `MKMapItem` `openInMapsWithLaunchOptions:launchOptions`

Example:

CLLocationCoordinate2D endingCoord = CLLocationCoordinate2DMake(40.446947, -102.047607);
MKPlacemark *endLocation = [[MKPlacemark alloc] initWithCoordinate:endingCoord addressDictionary:nil];
MKMapItem *endingItem = [[MKMapItem alloc] initWithPlacemark:endLocation];

NSMutableDictionary *launchOptions = [[NSMutableDictionary alloc] init];
[launchOptions setObject:MKLaunchOptionsDirectionsModeDriving forKey:MKLaunchOptionsDirectionsModeKey];

[endingItem openInMapsWithLaunchOptions:launchOptions];

This will start the navigation for driving from the current location.

Before launching url, remove any special character from the url and replace spaces by +. This will save you some headaches:

NSString *mapURLStr = [NSString stringWithFormat: @"http://maps.apple.com/?q=%@",@"Limmattalstrasse 170, 8049 Zürich"];

mapURLStr = [mapURLStr stringByReplacingOccurrencesOfString:@" " withString:@"+"];
NSURL *url = [NSURL URLWithString:[mapURLStr stringByAddingPercentEscapesUsingEncoding: NSUTF8StringEncoding]];
if ([[UIApplication sharedApplication] canOpenURL:url]){
[[UIApplication sharedApplication] openURL:url];
}

Updated to Swift 4 based on @PJeremyMalouf's answer:

private func navigateUsingAppleMaps(to coords:CLLocation, locationName: String? = nil) {
let placemark = MKPlacemark(coordinate: coords.coordinate, addressDictionary:nil)
let mapItem = MKMapItem(placemark: placemark)
mapItem.name = locationName
let launchOptions = [MKLaunchOptionsDirectionsModeKey: MKLaunchOptionsDirectionsModeDriving]
let currentLocationMapItem = MKMapItem.forCurrentLocation()

MKMapItem.openMaps(with: [currentLocationMapItem, mapItem], launchOptions: launchOptions)
}