The importance of “off-peak”

A couple of weeks ago I got to meet Jarrett Walker, the guy behind the excellent “Human Transit” blog. We had a number of transport geeks in the same room, and unsurprisingly the result was a pretty interesting conversation. There was one thing in particular that Jarrett mentioned, which I think is certainly worth repeating, and that is: “the quality of a public transport system should be measured by how it performs at 7pm on a Sunday night, rather than at peak hour.” I completely and utterly agree. “But why?” I hear you ask. “Shouldn’t we really be far more concerned about the quality of the public transport system at peak hour when it’s most well used?”

The answer to that is quite complex, and delves to the heart of the question “what are the benefits of a good public transport system?” Is it just to “knock the top off” peak hour congestion, or do we want public transport to offer a true alternative to driving, a system that makes it possible for people to live decent lives without having to own a car and use for the majority of their trips – whether to work, school, play, visit friends or whatever. Is it to offer a transport system that will encourage a more sustainable urban form, that lowers our environmental impact and our reliance on fossil fuels? In many ways it comes down to whether we’re just providing commuter transit, or whether we’re providing urban transit.

From my perspective, I think that public transport is important because of its ability to drive more sustainable urban forms, and (mainly in overseas cities) its ability to allow people to live a full life without a car. Of course it’s also important to “knock the top off” peak hour congestion, as we’d need twice as many lanes of roading into Auckland’s CBD (and goodness knows how many more carparks) if it weren’t for our public transport system, but my issue is that generally when we look at public transport, the sole focus is on what happens at peak hour (the economic evaluation manual for public transport just about completely ignores off-peak issues).

The reasons for trying to make public transport an attractive option for non-commuting, non peak hour trips, become fairly obvious when you read the following tract from the excellent book Asphalt Nation by Jane Holtz Kay:

The nation is in “lifelock” to the automobile as the dominant means of transportation. It is in its grip so securely that we can barely perceive how both the quality of mobility and the quality of life have diminished. For the startling fact is that it is not just the journey to work, not only the dashboard-pounding commuter, who creates the bulk of traffic and logs in the lost time, but all of us. In fact, the commute itself consumes less than one-quarter of all our trips, a smaller percentage than two decades ago. Specifically, work-bound travel devours only 22.5 percent of the pie graphed by the Nationwide Personal Transportation Study of the Federal Highway Association.

Statistically, most of our expanding hours behind the wheel, nearly eight of every ten vehicle miles we travel, have nothing to do with work. Neither are these miles vacation trips or long-distance travel, the reasons Americans give for buying the first – or second or third – automobile. Such holiday trips consume fewer miles than might be thought, a scant 8 percent of our total mileage.

What sets the odometer reeling is something else. It is something less critical than life. liberty or the pursuit of happiness. And that is errands. According to the highway administration study one-third of the miles we travel go to consumption and family chores. A bottle of milk, a tube of toothpaste, a Little League game, taking grandma to the hospital or junior for eye glasses spin the miles. The ministuff of life clogs the nation’s roads. another third falls under the “social and recreational” category. These are the hours of amusement and friendship reached by wheel: a workout, a movie, a dinner. Total these lifestyle choices and tally the chores to consume, survive, and fraternize and we have covered two-thirds of our driving miles, more than half of the ten to twelve thousand miles of travel per car per year.

There key statistic in my opinion is how low the percentage of trips for commuting is – at only 22.5%. While I’m not exactly sure of the figures for Auckland, one would guess it might be relatively similar. Which means that three out of four trips taken are not for work purposes, they’re not commuting trips. So our obsession with only providing public transport for commuting trips means that we’re basically ignoring three-quarters of the potential market for public transport, three quarters of the potential opportunities to reduce our oil dependency, our CO2 emissions and so forth.

Furthermore, there are some distinct operational advantages that arise from having a greater focus on capturing off-peak, non-commuting trips. Of course, there are many difficulties, but I will look at the advantages first.The most obvious advantage is that you’re unlikely to need to buy any more buses or trains, or built anymore tracks or busways – peak hour requires so many buses, trains, tracks and so forth that during off-peak hours you can simply use what you’ve already got more frequently and therefore utilise that investment more efficiently. “Commuter focused” systems are inherently pretty inefficient: all the buses and trains spend half their times on the road/tracks near empty, because they’re returning from their peak load trip, while having a lot of rolling stock or infrastructure capacity that is only needed a few times a day is also a very inefficient use of that investment. Offering a better off-peak service, in a way that can attract more patronage, is actually likely to be a fairly inexpensive undertaking – as the only extra costs are for staffing and fuel.

But how can we make public transport more attractive for off-peak, non-commuting trips? Well this is where the network effect becomes most important. These kinds of trips usually have very dispersed destinations, they are often “spontaneous trips” where you don’t want to have to check timetables and is easily understood (because you might be taking somewhat unusual/infrequent trips). So you need a public transport system that has high frequencies, is simple to understand and can take you “from anywhere, to anywhere”. These are the three three issues that traditional public transport struggles to provide for, but at the same time are the main gains from applying the network effect idea.

Ultimately, if you just want public transport as a tool to ease peak hour congestion, then what will really matter is what happens during peak hour. But if you really want to use public transport as a tool with wider benefits: to reduce oil dependency, vehicle emissions, provide people with a real alternative to owning a car and to drive more sustainable urban forms, then we really need to think a lot more about what we do with public transport “off peak”. Because, after all, three out of every four car trips aren’t for commuting reasons.

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