<story><title>A single line to 3 cashiers is ~3x faster than a separate line for each cashier</title><url>http://online.wsj.com/article/SB10001424052970204770404577082933921432686.html</url></story><parent_chain><item><author>rdtsc</author><text>Not trying to be condescending but doesn&apos;t it surprise anyone here that this is _not_ obvious? At least on this site, there are still people doubting or debating this.&lt;p&gt;So I am wondering why don&apos;t stores do this already. And I believe it is because of perceptions. They understand that time will be saved, however, they realize that most people will be scared by a long line.&lt;p&gt;One long line that moves fast will still appear terrible compared to a bunch of small lines that crawl. Because people don&apos;t look long enough to estimate the rate of movement. They see both lines as static (not moving).</text></item><item><author>pnathan</author><text>FYI: This is an example of the branch of mathematics called queueing theory.&lt;p&gt;&lt;a href=&quot;http://en.wikipedia.org/wiki/Queueing_theory&quot; rel=&quot;nofollow&quot;&gt;http://en.wikipedia.org/wiki/Queueing_theory&lt;/a&gt;&lt;p&gt;It&apos;s a fascinating study requiring a good knowledge of probability to use beyond the simplified models.  It turns out from the math that throughput using a single queue is better than using multiple queues.</text></item></parent_chain><comment><author>philwelch</author><text>It&apos;s another instance of &quot;people are stupid&quot;. Yes, for any educated person it&apos;s obvious that one line is faster, that&apos;s the first thing about queueing theory, but most people don&apos;t know the first thing about queueing theory.&lt;p&gt;Other instances of &quot;people are stupid&quot; leading to poor design:&lt;p&gt;* Some cars come with a CVT (continuously variable transmission) rather than having to shift gears. The audible pitch of the engine just gradually goes up as the accelerator is depressed, rather than revving up and then shifting back down again. Since people were used to the gear-shifting behavior, they thought CVT&apos;s were underpowered, so they were actually redesigned to simulate the shifting behavior even though it was suboptimal.&lt;p&gt;* Coinstar machines are actually much, much faster than they appear. But people don&apos;t trust them if they don&apos;t take three times as long and make jangly coin sounds, so it just silently sorts the coins as fast as it can and plays a recording of jangly coin sounds, all the while delaying when it displays the final count onscreen.</text></comment>
<story><title>A single line to 3 cashiers is ~3x faster than a separate line for each cashier</title><url>http://online.wsj.com/article/SB10001424052970204770404577082933921432686.html</url></story><parent_chain><item><author>rdtsc</author><text>Not trying to be condescending but doesn&apos;t it surprise anyone here that this is _not_ obvious? At least on this site, there are still people doubting or debating this.&lt;p&gt;So I am wondering why don&apos;t stores do this already. And I believe it is because of perceptions. They understand that time will be saved, however, they realize that most people will be scared by a long line.&lt;p&gt;One long line that moves fast will still appear terrible compared to a bunch of small lines that crawl. Because people don&apos;t look long enough to estimate the rate of movement. They see both lines as static (not moving).</text></item><item><author>pnathan</author><text>FYI: This is an example of the branch of mathematics called queueing theory.&lt;p&gt;&lt;a href=&quot;http://en.wikipedia.org/wiki/Queueing_theory&quot; rel=&quot;nofollow&quot;&gt;http://en.wikipedia.org/wiki/Queueing_theory&lt;/a&gt;&lt;p&gt;It&apos;s a fascinating study requiring a good knowledge of probability to use beyond the simplified models.  It turns out from the math that throughput using a single queue is better than using multiple queues.</text></item></parent_chain><comment><author>cheald</author><text>Fry&apos;s Electronics does the single line thing, and any time there is a line, I feel like I end up standing in it longer than I would at a grocery story. I suspect this is probably psychological, but letting me, as the shopper, pick the line I want to stand in puts me in charge of how long I wait. If I pick a bad line, it&apos;s my fault for picking the bad line. When there&apos;s just one line available, I don&apos;t get that choice.&lt;p&gt;Single-queue might be faster, the the psychology of customer satisfaction is much more complex than that.</text></comment>