How to generate my traveled path using CLLocationManager on google map in iOS?

User has to create his own path on google map wherever he move step by step the route is generated.

please have look on my code snippet:

- (void)locationManager:(CLLocationManager )manager didUpdateLocations:(NSArray )locations
{

    CLLocation* location1 = [locations lastObject];

    if (self.endPointArray == nil)
    {
        self.endPointArray = [[NSMutableArray alloc]init];
    }
    NSString *pointString=[NSString    stringWithFormat:@"%f,%f",location1.coordinate.latitude,location1.coordinate.longitude];
    [self.endPointArray addObject:pointString];
    NSLog(@"end point array :%@",self.endPointArray);
    GMSMutablePath *path = [GMSMutablePath path];
    for (int i=0; i<self.endPointArray.count; i++)
    {
        NSArray *latlongArray = [[self.endPointArray objectAtIndex:i]componentsSeparatedByCharactersInSet:[NSCharacterSet characterSetWithCharactersInString:@","]];

        [path addLatitude:[[latlongArray objectAtIndex:0] doubleValue] longitude:[[latlongArray objectAtIndex:1] doubleValue]];
    }

    if (self.endPointArray.count>2)
    {
        GMSPolyline *polyline = [GMSPolyline polylineWithPath:path];
        polyline.strokeColor = [UIColor redColor];
        polyline.strokeWidth = 3.0f;
        polyline.map = _mapView;
    }
}

I have create route with help of above code.but sometimes we get unexpected coordinates from CLLocation. If we are on road (route) it's gives perfect but if we are not on road like in home it gives wrong coordinates