I would like to know how to get the speed of a vehicle using your phone while seated in the vehicle using gps. I have read that the accelerometer is not very accurate. Anoth
GPS works fine in a vehicle. The NETWORK_PROVIDER setting might not be accurate enough to get a reliable speed, and the locations from the NETWORK_PROVIDER may not even contain a speed. You can check that with location.hasSpeed() (location.getSpeed() will always return 0).
If you find that location.getSpeed() isn't accurate enough, or it is unstable (i.e. fluctuates drastically) then you can calculate speed yourself by taking the average distance between a few GPS locations and divide by the time elapsed.