Divide one hundred guests by a twelve-passenger Sprinter and you get nine vehicles. That number is almost never correct, in either direction, and the reason is worth understanding before you build a budget around it.
Capacity answers the wrong question
Capacity tells you how many people fit in one vehicle at one moment. What you actually need to know is how long a guest waits, which is a function of how often a vehicle appears — and that depends on the round-trip time, not the seat count.
A hundred guests moving in a single simultaneous wave — a gala departure, a stadium exit — really is a capacity problem, and nine vehicles is roughly right. A hundred guests trickling between a hotel and a venue over three hours is a frequency problem, and three vehicles running a tight loop will serve them better than nine sitting idle.
The three shapes of an event movement
- Wave — everyone moves at once. Sized by capacity. Gala arrivals, stadium exits, a keynote start.
- Loop — guests move continuously over a window. Sized by frequency: round-trip time ÷ promised interval.
- Assignment — named individuals with fixed times. Sized one to one. Speakers, executives, sponsors with clients.
Most real programs are all three at once, which is why a single vehicle count across a whole event is usually meaningless. Size each movement separately, then look for vehicles that can serve two of them.
A worked example
One hundred delegates, two downtown hotels, a venue eight minutes away, arriving across a ninety-minute window before a 09:00 keynote, with a five-minute promised headway.
| Input | Value |
|---|---|
| Drive time, each way | 8 minutes |
| Dwell at each stop | 3 minutes |
| Round trip | ≈ 22 minutes |
| Promised headway | 5 minutes |
| Vehicles required | 22 ÷ 5 ≈ 5 |
| Seats delivered per hour | 5 vehicles × ~3 trips × 12 seats ≈ 180 |
Five Sprinters, not nine — and they deliver 180 seats an hour against a requirement of roughly 67, which is the margin that absorbs a late vehicle without breaking the promise. Squeeze it to three and the headway becomes seven minutes on paper and fifteen the moment anything goes wrong.
What pushes the number up
- Luggage. Airport waves are limited by bags, not seats — a twelve-seat Sprinter carrying eight bags carries eight people.
- A longer loop. Every minute added to the round trip needs proportionally more vehicles to hold the same headway.
- Traffic that is not symmetric. Outbound at 08:30 and inbound at 08:45 are not the same drive; size on the slower leg.
- Guests who will not share. Some programs promise privacy, which converts a loop back into assignments.
- The exit. A venue that empties in one wave needs wave capacity even if arrivals were a loop.
What brings it down
Consolidating hotels, widening the arrival window by even twenty minutes, and being honest about the interval you actually need. A ten-minute headway that holds is worth more than a five-minute one that does not, and it costs roughly half.
Staging also counts. A vehicle that can turn around at the venue without re-entering traffic saves several minutes per rotation, which on a tight loop is worth a whole vehicle.