The Regional Transit Task Force (RTTF) has been looking at both reduction and growth scenarios. Today I’ll give you an update on the reduction scenarios and tomorrow I’ll give you an update on the growth scenarios. It’s worth noting that the Council has given the RTTF more time to conduct it’s work, which certainly seems necessary.
As I reported a while ago there is generally agreement that reductions should be made based on productivity. After all if you want to increase the efficiency of a system, productivity is the measure to use.
As more scenarios are developed the obvious is emerging, any cuts based on productivity will be best for the west subarea, worst for the east subarea and roughly neutral for the south subarea. On the flip side it appears significant efficiencies could be attained from redesigning Metro’s transit service. This could be good or bad depending on the specific change and your point of view but it would certainly impact the west subarea most, simply because it has the most service as well as the most service “artifacts” that can create a less than optimal system. Both of these things, getting rid of subarea based service allocation and redesigning the bus system obviously aren’t politically easy to do.
To further explore other reduction options Metro has added three new reduction scenarios R0, R2, and R3. R1 was the first reduction scenario discussed and had a refreshing and balanced approach, essentially a system designed by transit planners, not politicians.
- R0: Productivity based reductions, regardless of subarea.
- R1: Reduction made using a three screen process regardless of subarea. First unproductive service (less than 10 riders per platform hours or 50 passenger miles per platform hours) are removed, reduced or redesigned. Second service is added back according to goals of connecting housing and job centers, ensuring mobility for minority/student populations, and lifeline services over broad geographic areas. Third system design efficiencies are applied. This means leveraging ST service, consolidating routes, prioritizing frequent arterial service, etc.
- R2: Productivity based reductions, done on a subarea basis. Reductions per subarea are based on percent of service hours each subarea currently has (west 62%, south 21%, east 17%). This essentially is Metro’s current policy.
- R3: Uses the same three screen process as R1 but applied by subarea as in R2.
Lots more after the jump. The modeling for these four scenarios reveals some obvious results and some not so obvious results.
First off, scenarios with subarea based cuts perform worse than scenarios which make cuts regardless of subarea (R0>R2 and R1>R3). Since subarea cuts are set by policy each subarea only has to cut enough service hours to meet these prescribed cuts (62% west, 21% south, 17% east). This creates a situation where the east subarea has a low service reduction threshold of ~8 riders per platform hour cut (R2,R3), while the west subarea has a much higher threshold of ~23 riders per hour cut. This means that for every 23 west subarea riders potentially kicked off Metro, just 8 east subarea riders will be kicked off. Posed in this way you can make some strong equity arguments counter to the typical subarea area equity argument. Essentially subarea equity gives preferential treatment to some riders just because they live on the east side of Lake Washington.
Additionally scenarios which simply cut service hours perform much worse than scenarios that consolidate, redesign or leverage ST service (R1>R0 and R3>R2). This is not surprising but the scale of the impact is. Any reduction scenario must have significant system design changes if lose of riders is a priority. Financial pinches like this are sometimes the only wayto force agencies to improve system design. Financial pinches make the status quo impossible to maintain, so the default option of inaction is eliminated. Hopefully enough good changes can be found to make this process a positive experience.
Now come some of interesting results. Holding one factor constant (system design or subarea approach) I got the graph below.
What you see is that enforcement of subarea equity increases the number of riders you lose, while redesigning the system reduced the number of riders you lose. Remember under all of these scenarios Metro loses riders, they just lose less when subareas aren’t enforced and when the system is redesigned. The second bar from the left is very interesting. The only difference between R1 and R3 is whether or not subareas are enforced. To me this shows that a well structured transit planning process (three screen process used in R1 and R3) can deliver on the intent of subarea equity (service all over the county, appropriate for the context and meeting goals or social equity,geographic coverage, ecconomic development, etc.) while minimizing ridership loss, all without resorting to strict percentage based subarea equity policies. The bar on the far right also shows that if subarea equity is keep system restructuring is critical to minimize ridership loss.
These scenarios only address how service reduction occurs. A separtate question is whether these reductions should be treated as cuts or suspensions. In the long term treating them as cuts causes a net lose of service for the west subarea and a gain in east and south subarea. Treating reductions as suspensions would be neutral.
So to sum everything up R1 is still the best plan by far. R2 which essentially is the default reduction plan is by far the worst. R0 is a lose-lose proposition and R3 is a mixed bag.