more on Episode Four's "economical driving" challange

[Questor]

Using the technology of veed eee owe taap, I record a few episodes
of The Amazing Race in a loop, and each week before I record the
current episode I re-watch one from a couple of weeks previous.
I just watched episode four, and I noted all the dashboard readings
in the "economical driving" challange. Here's the raw data, in
order of team arrival:

team name
elapsed time, miles driven, mpg, gallons used

1. bike messengers
00:42:46, 19.3, 973.2, 0.01

2. dentists
01:12:52, 21.3, 133.6, 0.15

3. wrestlers
00:48:31, 19.3, 103.1, 0.18

4. tennessee
00:47:56, 19.4, 306.0, 0.06

5. surfers
00:50:26, 19.3, 88.5, 0.21

6. scientists
00:48:34, 19.3, 103.1, 0.18

7. Tim & Te Jay
00:36:41, 19.6, 121.6, 0.16

8. mother/daughter
01:01:26, 22.4, 267.8, 0.08


Based on the edit, the bike messengers were first with a healthy lead.
Next were the dentists, and after a short gap the wrestlers, tennessee,
the surfers, and the scientists are depicted as arriving close together.
After another gap Tim & Te Jay cross the bridge, and finally the
mother/daughter team.

If wind was a major determining factor in using as little gas as possible,
why was team tennessee the only team to succeed out of four teams that
crossed the bridge at essentially the same time?

While I think that an environmental condition played a part in who was
successful and who wasn't, I suspect it was traffic, not wind, that
helped determine who made the cut. Slowing down and speeding up to
adjust to other vehicles happens more frequently in heavier traffic,
and that uses slightly more fuel. My guess is that the three teams
who succeeded crossed the bridge when traffic, at least in the vicinity
of their car, was light.

Also note the miles driven and elapsed times. Apparently the direct
route is 19.3 miles, but a couple of teams either made a wrong turn
or took a slightly longer path, which apparently cost them time as
well.

[Ken McElhaney]

On Tuesday, November 18, 2014 7:58:02 PM UTC-6, Questor wrote:

*stuff snipped*

Post by Questor
Based on the edit, the bike messengers were first with a healthy lead.
Next were the dentists, and after a short gap the wrestlers, tennessee,
the surfers, and the scientists are depicted as arriving close together.
After another gap Tim & Te Jay cross the bridge, and finally the
mother/daughter team.

Yup

Post by Questor
If wind was a major determining factor in using as little gas as possible,
why was team tennessee the only team to succeed out of four teams that
crossed the bridge at essentially the same time?

That's pretty simple. Your question is based on the assumption that ALL the teams were trying to drive efficiently. The three teams that did actually make it under the limit were shown to be emphasizing just how efficiently they were driving while some of the other teams either didn't fully understand or pay attention very well.

Post by Questor
While I think that an environmental condition played a part in who was
successful and who wasn't, I suspect it was traffic, not wind, that
helped determine who made the cut. Slowing down and speeding up to
adjust to other vehicles happens more frequently in heavier traffic,
and that uses slightly more fuel. My guess is that the three teams
who succeeded crossed the bridge when traffic, at least in the vicinity
of their car, was light.

Well, I don't remember seeing any heavy traffic on the bridge for any of the teams in the video, at least not enough to show any real difference.

However, you are making another assumption that ALL the teams were trying to maintain the same speed as the surrounding traffic. Highways generally have maximum AND minimum speeds. For teams to drive "efficiently, they would not be trying to drive the same speed as the traffic on the highway, but instead would drive slower so that ALL the traffic would pass them and become basically no factor at all.

A team that entered the highway would have to accelerate to reach at least the minimum required speed and maybe just a little faster. By staying in the right hand lane like we saw most of them do, they would not have to change lanes.

About the only thing they would have to take into account would be entering traffic. But since a big portion of their journey was over a bridge, that would not be a factor. On Google Maps, that bridge was about 10 miles long which was more than half their trip. Plus, the airport from where they left was right next to the bridge and the first exit would take then straight into Malmo. So incoming traffic would hardly be a factor at all.

Post by Questor
Also note the miles driven and elapsed times. Apparently the direct
route is 19.3 miles, but a couple of teams either made a wrong turn
or took a slightly longer path, which apparently cost them time as
well.

It's interesting that the Mother/Daughter team traveled three miles further, yet managed to stay under the limit.

I'm still seeing the wind being the primary factor with the three teams that we know tried to drive efficiently. When you consider the paltry difference between .01 and .06 in terms of gallons (1% to 6% of a gallon) and the way they seemed to stay slower than the traffic (particularly the bikers), then the wind certainly seems to be the only variable left.

Ken