On Monday I wrote about the Regional Transit Task Force (RTTF) reduction policy. Today I’m going to touch on the growth policy with a few of my concerns. Less work has been done on this to date and it is therefore more conceptual than the reduction scenario.
The RTTF has advanced the concept that service growth should be based on two principles, responding to existing transit demand and supporting regional growth. The image above shows the results of this conceptual approach. To get these results Metro staff used one measure for responding to demand and six measures for supporting regional growth (details here). Using these measures and a scoring system a “desired minimum level of service” is calculated. If current transit service doesn’t meet this desired level of service, then a need has been identified and future service hours will be used to address the gap between desired level of service and current level of service.
This type of analysis is good because it is objective and based on context, not arbitrary policy, but it has limitations. The hard part is determining what measures to use, what ranges to use, and what weighting to give each range. Unless all factors are rigorously linked to a factual basis they can become value judgments. Select a certain set of measures, ranges and weights and you can skew results. Using objective measures is much better than the alternative, but I think this concept has to be significantly refined and I’m uncomfortable where it stands.
First off, I’m worried by the whole premiss of a “desired minimum level of service” will cause Metro to focus all of its effort and money on building lower productivity routes up to that level of service. To be clear, I’m not saying that I think investments in these corridors should not occur, but I don’t see a clear path that leads to higher frequency all day service on corridors that exceed these minimums, which most of the core routes and RapidRide routes already do. There must be some measure or set of measures that leads to better service for the highest ridership routes or else service improvement on most of the above mentioned routes will only occur with crowding.
On the topic of crowding “ie following demand”, only one measure, with a high threshold, is used. Commuter routes must have a load of 1.0 or greater for more than 20 minutes or a load factor 1.2 or greater for more than 20 minutes for local routes. This is meant to deal with peak period loads and should be addressed as a necessity not an extra. I get the feeling that task force members are counting this as part of Seattle portion of the pie, when in fact this is necessary to meet the basic capacity needs of the most productive routes in the entire Metro system. This extra service will go to peak periods, doing very little to increase off peak frequencies or span of service. Excluding these service hours only 17% of total service hours will go to improve west subarea routes to “desired minimum level of service” while 33% goes to the east and 31% go to the south.
One thing I’m not clear on is where this leaves other non “frequent arterial”, ie 30 minute or better headways all day long service, which is makes up 47% of east subarea service hour. If this means that the county is de emphasizing this type of service I think it would be a step in the right direction. It if does not, then any additional service hours for those types of service will heavily favor the east and south subarea.
So I said before, it’s a good start but I have some serious concerns with it.