Flickr - Stephen Rees - Translink busA few weeks back, Vancouver, BC-based urban planner Zach Shaner posted a comparison of bus transit service in Seattle and Vancouver.  Shaner’s basic claim—that Vancouver’s bus service just works better than Seattle’s—is hard to dispute. A few years ago I reached the same conclusion, based on the fact that  TransLink, BC’s transit agency, provided far more bus rides per capita than did greater Seattle’s.

But while I totally agree with Shaner’s diagnosis, I just don’t buy his explanation for Vancouver’s transit advantage.  Shaner argues that three key factors vault Vancouver’s transit service ahead of Seattle’s:  (A) more frequent bus service; (B) a single unified bus system ratherthan6separateones; and (C) fewer hills.

While each of these factors is legit, at least in a limited way, I think Shaner is overlooking a root cause that’s far more critical than any of those:  Vancouver’s vast advantage in limiting sprawl, and creating compact, transit-oriented neighborhoods.

I think the numbers back me up on this.

  • One easy way to see the importance of neighborhood design is to look at metrics of transit service efficiency.  Look, for example, at the number of riders who board the bus per hour of service.  The higher that number, the more riders a bus system can serve with a limited pot of money.  TransLink reports that about 47 riders board the bus (numbers derived from p. 11 of this TransLink quarterly report), on average, during each hour of bus service.  But according to the National Transit Database, the figure is just 33 boardings per hour in greater Puget Sound, counting all 6 bus agencies that service the region.

    Now, I suppose it’s possible to argue that if only greater Seattle ran buses more often, its transit service would gradually get more efficient, with more and more passengers getting on the bus during each hour of bus service.  Unfortunately, this appears to be wishful thinking.  Yes, when bus frequency goes up, more people do ride the bus.  But studies show that ridership tends to grow more slowly than does bus service frequency.  The always-helpful Victoria Transport Policy Institute has the scoop, in a review of “transit elasticities“:

    The elasticity of transit use with respect to transit service frequency (called a headway elasticity) averages 0.5, with greater effects where service is infrequent.

    So, roughly speaking, a 10% increase in bus frequency nets a 5% increase in passengers.  Economists call this a relatively inelastic relationship.  And it means that, if buses ran more frequently in greater Seattle, then boardings-per-service-hour would likely decline, rather than improve to Vancouver’s levels.  (Five percent more riders spread across 10 percent more buses means that each bus would be a bit emptier than it is today—which might be ok if you’re a rider, but a costly inefficiency if you’re a bus system planner with a limited budget.)  With fewer riders per service hour, it becomes a severe financial strain to support high-frequency bus service.

    That suggests that frequency of service isn’t at the root of Vancouver’s transit edge.  Or, at least, it’s not an independent explanation for that edge.  Instead, Vancouver’s high-frequency bus service is made possible by a far more fundamental factor:  Vancouver’s more compact, transit-oriented neighborhoods put more jobs and people near transit lines.  And this compact neighborhood design makes it possible to support high frequency service with high ridership per bus.

    It’s kind of obvious if you think about it.  When people live close together, a single transit stop can service lots of people at once.  With stores and services close together, transit can link people to more of the sort places that they want to be, making cars less necessary.  Less sprawl means that bus routes can service more people and more destinations with less driving.  Compact, vibrant neighborhoods tend to have less surface parking than sprawling locales; and according to VTPI’s research, parking prices and supply are also major determinants of transit usage.

    In short, compact neighborhoods create a virtuous circle for transit ridership.  Metro Vancouver is far and away the most compact urban area in the Pacific Northwest; our analysis shows that no other city even comes close, really. And that fact gives greater Vancouver a huge transit advantage over far the far more sprawling Everett-Seattle-Tacoma corridor.

    I certainly don’t mean to be harsh on Shaner.  He’s got some good points.  Still, it always strikes me as wrong-headed to start any analysis of a transportation system by looking at the characteristics of the roads and vehicles.  More important is where the people are, and where they want to go.  If you start by looking at people and places first, then you’ve got a much better shot at understanding the dynamics of how the transportation system works.

     

    Bus Photo courtesy of Flickr user Stephen Rees under a Creative Commons license.