Hidden Assumptions

“It isn’t what we don’t know that gives us trouble, it’s what we know that ain’t so.” – attributed to many including Samuel Clemens, Will Rogers, Satchel Paige, and Artemus Ward

It is possible to make some nasty mistakes because of hidden assumptions.

Google Maps definitely simplifies the problem of getting from point A to point B, but I have to wonder what details it leaves out.

Occasionally, I make a trip from Kamloops to Nelson (both in British Columbia). Google Maps gives me three routes. They are:

Distance Travel Time Notes
456 km 5:42 northern, has a ferry
455 km 5:52 middle
500 km 5:44 southern

It appears that the second route is best, because it is the shortest, and one avoids the possibility of missing a ferry.

However, there is data missing.

1) The second route also has a ferry on it.

2) The first two routes have long stretches of twisty highway where one frequently has to brake. The third has long straight stretches.

Are the travel times based on actual travel time or supposed from speed limits? Google Maps also gives travel times without traffic, but what exactly does “without traffic” mean?

If you know the routes, then the third route is definitely best time-wise.

Watch for hidden assumptions!