It's not much use because it gives straight line distances and, not being a crow, that does not help much. One example I tried (Fethiye to Denizli) gives straight line over a mountain range where there are no roads; the actual driving distance is probably three times longer.
As far as I can see Ian it gives the distance by road as well as the straight line distance?
For instance I've just inquired as to the distance between Turgutreis and Izmir and it says 'The Distance between Turgutreis (Mugla Province) and Izmir (Izmir) is :
155.91 kilometers (km).
The approximate travel/road distance can be around 179.3 km to 194.89 km'