Regarding "Airports and the Wealth of Cities"

Airports and the Wealth of Cities

If passengers is significant, but number of flights is not, that implies that success lies in having larger than average planes come in. Ie, a hub airport. Assuming that the the cost of flying is proportional to the square of size, while the passenger capacity is proportionate to the cube, larger planes offer lower seat-costs per passenger. Hence, the use of larger planes may also imply that the average seat-price to visit such an airport is lower. Status as a 'hub' airport also offers substantial accessibility benefits: More flights to more places, at greater frequencies, than for non-hub airports (ie, San Diego).

Limits on Connections

Jared Walker talks about connections here. He's established a 'floor' for connections, demarcating when it becomes useful to use connections and avoid the spaghetti overlay. What about the ceiling? How often is is reasonable to ask people to make a connection, in terms of a) Connections per trip, and b) distance between connections?

Regarding a): Personally, if a transit trip involves more that one connection, I either find an alternate that involves a greater than half mile walk, or don't make the trip.

Regarding b): The urban* heuristic is: "Is it faster to walk"? is always a good metric. Ie, if the wait time+transit travel time > walk time, walk. Assume urban Salt Lake City conditions (15 minute headway, 8 blocks/mile). Assume 'random' wait times, so that connections have not been timed, any connection imparts a 7.5 minute wait time. At 3 mph walking pace, you can walk 3/8ths of a mile in that time--3 SLC blocks. At an average 12 mph bus speed (time spent at stops included). Thus, a bus will carry you 12 blocks in the time it takes you to walk 3, once you get on it.

This implies that it is worthwhile for the average person to make a connection, if it will save three blocks of walking. But this analysis presumes a time-only comparison, where real connections have other factors to be considered.

*At the suburban scale, it's almost always faster to wait, simply because the distances you are taking transit is measured in miles, not blocks.

Why Connections Suck--and how to make them better.

I've waited for the bus in the cold, dark, pre-dawn hours, uncertain, doing the 'bus-bob', as I look up the roadway to see if I can spot the bus coming yet. Alone, hoping I'm there at the right time--when the bus actually comes, not when the schedule says it is coming. Sometimes standing in snow, sometimes with a face full of freezing sleet, and sometimes in the burning sun. Asking me to make a 'connection' between two buses asks me to do this twice. As I've mentioned, I'm totally unwilling to make two connections in a transit trip. I'd rather walk a half mile than wait twenty minutes someplace unpleasant. In fact, for most trips, I'm unwilling to make even a single connection between two buses. There is too much uncertainty.

A notable exception is when I'm waiting for TRAX. It's less the vehicle than the amenity the TRAX platform represents. I'm out of the rain, can find some shelter from the wind, and don't have to stand on snow or ice. But it's more than that--I'm not alone. I can see that there are other people there, that a train is coming (I haven't misunderstood the schedule, or just missed the train). And I have access to a train schedule, and a clock, so I know how long my wait is going to be. And, should I so desire, I have someplace to sit. Which is an insignificant thing for a first five minutes, and welcome respite thereafter.

Want to improve the quality of connections? Improve the quality of the connections location.