Can you explain what your use case is?
1/second is about 14m for 50mk/h in cities. I guess where streets are realy narrow and closet together (medieval city centers?), you would not even drive that fast. GPS accuracy is mostly not much better anyway with many buldings around, you may likley not even gain anything. And at much higher speeds on highways the exits are much further apart, anyway.
I am not sure, but guess that higher data rates on your GPS readings (you can increase to 3/second or higher) as well as processing them cost you battery power, hence I would like to make sure there is a use case really worth it ...