Question: In my application, I am starting the Google Navigation with the help of following set of code.

```
String uri = "http://maps.google.com/maps?saddr="+ gpsLatitude
            + "," + gpsLongitude
            + "&daddr="
            + updateAcceptedOfferDetailsData.getDestinationLat()+","+updateAcceptedOfferDetailsData.getDestinationLon();
            Intent intent = new Intent(android.content.Intent.ACTION_VIEW,
                    Uri.parse(uri));
            intent.setClassName("com.google.android.apps.maps",
            "com.google.android.maps.MapsActivity");
            startActivity(intent);

```

I am passing the Source Lat/Lng and Destination Lat/Lng of the respective addresses.

**Problem:-** Here my problem is when the Navigation Screen opens there is no option to **"Start"** rather there is another option **"Preview"**, This problem do not happens at all the places it works fine for some places but not for all. May I know what the whole mess is??

Thanks

Answer: 
This worked for me:

"To anyone who runs across this thread, I discovered the cause and solution to this issue in some cases.

When you search for a location using google.com or the google app, then tap the directions button, the start and end points are passed to the google maps app. When you select the route and only see the preview option, it's because google.com/app passed a starting set of coordinates to the maps app, so your asking google maps to provide directions between two points, not your current location to a point. Thus no turn-by-turn. Simply tap into the start field and select current location, bam."
I have done some research on this and it appears that there is no way around it. The preview button will appear wherever navigation is not available for the requested route, the only reliable source I could find (Google was not massively helpful on this) to prove this is [here](https://support.google.com/gmm/answer/2839865?hl=en&ref_topic=3137719) which states (under navigation):

> 
> To launch turn-by-turn navigation, touch the Start navigation button represented by a chevron in the bottom right of the screen. When Navigation is not available, the icon will appear as a preview arrow , and you can view the directions step by step.
> 
> 
> 

The only suggestion that I have would be to somehow check whether or not navigation is in fact available for the given route prior to passing to the maps application, and if not then display a prompt to the user, but I do not know the android API's well enough to be of any help here. 

[A list of supported countries and territories is available here.](https://support.google.com/gmm/answer/172221?hl=en-GB) 

Hope this helps.