It is clear that in a life threatening situation one would be allowed to use his GPS system to navigate quicker to get a sick person to a hospital. In a life threatening situation every moment counts and therefore the GPS can be used because it helps you get to the hospital that much quicker.

The question arose when it is not a life threatening situation, such as a woman in labor (early stages let's say) or other examples where you have to get the person to the hospital but another couple of minutes will not make a difference.

Rav Yitzchak Zilberstein, Rav of Ramat Elchonon in Bnei Brak, was unsure of how to pasken. The question is can you use the GPS in order to minimize the driving and the "chilul shabbos" or can you not use it because that is an extra form of chilul b'yadayim - you are, in other words, performing one chilul shabbos that might not be necessary in order to minimize a second chilul shabbos that is necessary.

Rav Zilberstein sent the question to his father in law, Rav Elyashiv.

Rav Elyashiv, after weighing the options, paskened that one could use the GPS even in the situations where it is "pikuach nefesh" without the urgency (and a matter of minutes will not make a difference). His rationale was that because it is still a life threatening situation, even though it is not critical, it is still important to get to the hospital as fast as possible.