King County Metro has a very specific function. Their voter base is spread throughout the county, and it is their job to provide the highest quality transit service to the most of these citizens that they can. If you were in charge of the county and you started from scratch, with no buses and just a map and some data about the county, how would you design transit? First, you’d look at where most people lived and worked, since you know that commuting is a very strong transit need. You’d see that the largest job center was downtown Seattle, with Bellevue and Redmond as secondary job centers. And you’d see that a third of your citizens live in Seattle, but two thirds live elsewhere in the county. Then you’d consider your transit options.
More after the jump.
This is a chart I made comparing the appropriateness of transit technologies. It’s not based on data or studies, it’s my interpretation and you’re welcome to disagree in the comments. I’m defining a technology as more appropriate if it reduces your travel time and is convenient. For example, high speed rail will move you long distances quickly but would be infrequent, so wouldn’t be the best way to get from Ballard to downtown even if it ran between these two points.
Now, back to the county. Knowing most of your commuters are travelling more than a few miles, you’d be looking at light rail, heavy rail, frequent* buses, and scheduled buses. The buses aren’t as good as rail, and traffic is a real problem, but you might look at your budget and just buy buses. You’d get cheap scheduled buses most everywhere, and let them become frequent buses as lines merge. You’d also try to get road agencies to give you bus-only lanes to help solve the traffic problem.
And that would be a fine choice to make, overall. Metro is acting rationally. But the current system is only rational if you’re looking at the county level, with county average travel times and county average density. This ignores the fact that there’s a dense city inside King County. Take another look at the chart above. When you get below 5 miles, a scheduled bus stops making sense. The time and inconvenience spent is large compared to the distance travelled. And as you get down toward 1/2 mile, you might as well walk. Yes, multiple scheduled bus lines running the same path become frequent buses, but keep in mind that “Traffic” column – unless we run buses in their own right-of-way with real signal priority, even frequent buses are less appropriate than most other technologies at short distances.
There’s a reason that most counties have just one form of transit and most cities have many forms. I’ll be exploring these reasons and consider how Seattle would best be served by transit in future posts.
* Note: I’m considering “frequent” to be a bus that comes at least every 10 minutes – frequently enough that you don’t need to time your trip, just show up at a stop.
Here’s the updated, crowd-sourced version: