It was simply an investigation. You too found yourself curious enough of the device to be there.

[ if it'd just been him, he calculates that he could've easily covered enough distance to be in proximity of a road. however, the presence of the doctor means that spock's own calculations will have to be adjusted to include the abilities and limitations of mccoy, with respect paid to the harsh environmental factors. it made things more difficult, but perhaps it was a direct result of being on the enterprise too long, or in the proximity of kirk, but the vulcan wasn't about to ditch (no matter how much the other complained). there would be no man left behind. ]

The faster we move, the quicker we may be able to find shelter. It would be our wisest option at the moment.