# Walking with a Bicycle

**URL:** <https://boards.straightdope.com/t/walking-with-a-bicycle/538138>\
**Category:** Factual Questions\
**Created:** [May 3, 2010, 12:20pm UTC](https://boards.straightdope.com/t/walking-with-a-bicycle/538138 "2010-05-03T12:20:17Z")\
**Posts on this page:** 4\
**Page:** 2

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**Author:** ![ticker](https://avatars.discourse-cdn.com/v4/letter/t/d07c76/32.png) [@ticker](https://boards.straightdope.com/u/ticker)\
**Post date:** [May 4, 2010, 9:41am UTC](https://boards.straightdope.com/t/walking-with-a-bicycle/538138/21 "2010-05-04T09:41:10Z")

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I think it all becomes obvious when you realize that for much of the time both people will be simultaneously walking different parts of the route.

This is analogous to multi-core computers completing a task faster than a single one could when it is possible to split the task up into chunks and process them in parallel.

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**Author:** ![md2000](https://avatars.discourse-cdn.com/v4/letter/m/73ab20/32.png) [@md2000](https://boards.straightdope.com/u/md2000)\
**Post date:** [May 4, 2010, 3:19pm UTC](https://boards.straightdope.com/t/walking-with-a-bicycle/538138/22 "2010-05-04T15:19:16Z")

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> [@ghardester](#):
>
> To simplify even further.
> 
> The actions of both persons are identical, and the distance covered is the same for each, so you can reduce the equation by thinking only in terms of one person. You can also ignore however many times they did the bike/walk swap, it is just a mulitplier of the basic action and isn’t relevant.
> 
> Each individual walked for half the time to cover the distance and rode for the other half of the time. That is faster than the individual walking the whole way.
> 
> Nevermind how the bike got where, that is a detail that isn’t required in order to make the math clear.

Exactly. The journey is over when the last person gets to the end. That person basically alternated riding and walking, say average 50-50. So assume walking 3mph and cycling 12mph and it takes 1/2 + (1/2)x(3/12)= 5/8 of normal walking time.

Your mileage may vary.

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<div class="post-metadata">

**Author:** ![md2000](https://avatars.discourse-cdn.com/v4/letter/m/73ab20/32.png) [@md2000](https://boards.straightdope.com/u/md2000)\
**Post date:** [May 4, 2010, 3:20pm UTC](https://boards.straightdope.com/t/walking-with-a-bicycle/538138/23 "2010-05-04T15:20:40Z")

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Now what happens if there are 2 bikes and 3 people? 😉

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**Author:** ![EdwardLost](https://avatars.discourse-cdn.com/v4/letter/e/bbe5ce/32.png) [@EdwardLost](https://boards.straightdope.com/u/EdwardLost)\
**Post date:** [May 4, 2010, 6:13pm UTC](https://boards.straightdope.com/t/walking-with-a-bicycle/538138/24 "2010-05-04T18:13:07Z")

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It is true that someone is always walking. However, when everyone has stopped walking, less time has elapsed that would have elapsed if there had been no bike.

A better argument would be “every inch of the distance was traveled by someone on foot”.

To counter the latter argument you’d note that without the bike the whole distance would be traveled by two sets of feet. The bike allows you to reduce that to one pair of feet per inch and for the two people to walk simultaneously, covering different stretches of the distance. To see that more simply, imagine two highway line painters: instead of walking 2 miles together for an hour painting a double line, one starts at the half-way point and in half and hour their two separate lines join into one, 2-mile long line.

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