Grand Teton National Park, and to Salt Lake City

Earth Date: 2014 July 26th
Location: Grand Teton National Park, Wyoming --> Salt Lake City, Utah

Grand Tetons (through the bushes)

Saturday was a somewhat stressful day. We had five people (Amanda, me, Zach, Morgan, and Martha) to pile into the Prius along with all of our luggage. Morgan had a flight leaving Salt Lake City at 6:50pm, so our trip through the tetons was not as leisurely as we had hoped.

Morgan and Martha in front of the tetons

These were probably some of the best landscapes we saw during our trip. We stopped in the park at a Marina for lunch, before carrying on through. Around lunch time we checked our ETA at the airport. Siri claimed we would get there around 7:10! Naturally this was quite distressing. Adding to the confusion, Google Maps would give our ETA as around 6 pm (more than enough time). 

It took quite a while for us to find the source of the discrepancy. The routes that Google Maps and Apple Maps suggested were identical, yet differed greatly in the travel time estimate. The issue seemed to be I-15 through Idaho. If you have a long North-South journey on the Western side of the US, you may consider a detour to this highway as the speed limit is 80 mph almost all the way along it (at least in Northern Utah and Idaho).  It seems Siri had the speed limit plugged in as 65 mph, accounting for the time difference.

[Math 79 Question: Given the hour in time difference, how far did we travel on I-15 S?]