Total capacity is not the problem, shape is
The default rush brings 110 people in an hour to a window serving 75 an hour, and it is tempting to stop there and call it 35 short. The window keeps working for 30 minutes after the arrivals stop, so capacity across the whole episode is 113 — more than enough for everybody. It still loses 25 of them, because 40 percent of that hour lands in a fifteen minute block arriving at 2.93 a minute against a window doing 1.25.
Every walkaway on the page is caused by the shape of the rush rather than its size, and the distinction matters because the two have different fixes. A size problem needs a faster window or a longer service. A shape problem is sometimes solved by pre-orders, by a second hatch open for the fifteen minutes that matter, or by anything that moves people out of the block and into the flat forty-five minutes around it.
The line does not grow forever
It cannot, because people stop joining it. Tolerance is spread evenly between half and one and a half times the patience figure, so at 12 minutes nobody balks below a six minute wait and nobody joins above eighteen. That produces a self-limiting queue: it climbs through the peak block, tops out where the wait reaches the point most people will not accept, and drains once arrivals fall back.
The practical consequence is that a longer line is not a proportionally worse problem. Past a certain length the queue stops being what costs you money and the walkaways become it, and they are invisible — nobody inside the truck ever sees the person who looked at the line from forty feet away and carried on to the sandwich shop.
Speed does not buy losses back linearly
Ten percent more throughput does not recover ten percent of the walkaways. Near the edge of coping a small speed-up is worth a great deal, because the queue never reaches the length at which anybody leaves. A long way over the edge, the same speed-up barely moves the outcome, because the wait sits above what people accept for most of the peak either way. The scenario rows are there to show the shape of that curve for your own numbers rather than to recommend a rate.
What to do with the pavement figure
A queue at two and a half feet a person turns into a length of sidewalk very quickly, and that number belongs in a conversation with an event organiser or a property owner before the day rather than during it. Where a line may stand, whether it can cross a fire lane or an accessible route, and who decides any of that, are questions for the site and for the authority over it. This page produces a length in feet and no opinion at all about where it is allowed to be.
Questions people ask
How many customers can a food truck serve in a lunch rush?
Fewer than the window rate multiplied by the hours, because arrivals bunch and some people leave. Run the default figures — 110 arriving in an hour with 40 percent in one fifteen minute block, a window doing 75 an hour, and 30 minutes of serving after the rush ends — and the page serves 85 while 25 walk away, against a total capacity of 113 that would have covered everybody had they arrived evenly.
How long does the line get at a food truck?
It self-limits, because people stop joining once the wait crosses what they will accept. The page reports the longest the line gets, the minute it happens, and the same figure converted into feet of sidewalk at whatever spacing you enter. After the peak the queue stops growing not because service caught up but because arrivals stopped joining it.
Why do I lose customers when I have enough capacity for the day?
Because capacity spread over ninety minutes does not help somebody standing there at minute 30. If 40 percent of an hour arrives in fifteen minutes, the queue during those minutes grows faster than the window clears it, the wait crosses what people accept, and they leave. The loss comes from the shape of the arrivals, and the useful fixes are the ones that flatten the shape rather than the ones that raise the total.
How much faster does my window need to be?
Run the scenario rows and read your own curve, because the answer is not proportional. Recovering walkaways gets dramatically cheaper the closer you already are to coping and dramatically more expensive the further you are from it. The page will not recommend a rate, because the seconds behind any rate come from your own menu, your own stations and your own crew.
What patience figure should I use?
Your own, from watching your own line. An office crowd with a 30 minute break behaves nothing like a festival crowd with the whole afternoon, and a truck with no competition within four blocks holds people far longer than one in a lot with six others. The field is the wait at which about half your customers walk, and the model spreads tolerance evenly around it. There is no default that is right for anybody and the number in the box is a placeholder.