A 11/18/15 presentation I attended to the Eastside Transportation Association (ETA) concerning the “Mobility 21” alternatives to PSRC’s "Transportation 2040 Plan Update for King County and Region" prompted me to propose my own alternative.
Making Public Transit “Work”
It should be axiomatic reducing congestion on the area’s roadways requires convincing more commuters to use public transit. Doing so requires providing then with access near “where they live” to transit to “where they wish to go”. This area is fortunate in that “where they wish to go” is mostly limited to downtown Seattle, Bellevue, and Overlake areas. Conversely, the “where they want to go” in the Los Angeles area is so large that public transit will likely never “work” there.
The transit problem here is most of those wishing to go “there” are spread out over a very large area. (The most notable exception is West Seattle, where ST neglected to include a Prop 1 extension.) By comparison, BART, the successful west coast light rail transit system, benefits from the fact that large numbers of commuters live within walking distance of its four light-rail lines.
Having sufficient commuter access to light rail only reduces congestion if light rail has the capacity to accommodate them. BART not only has four separate lines, each line can accommodate 10-car trains. The station lengths in the Seattle tunnel limit Central Link trains to only four cars. Since light rail construction costs for 4-car and 10-car light rail systems are likely similar, Seattle light rail not only has less than half BART capacity it also has more than twice its cost/capacity ratio.
Each of the four BART lines operate with 15 minutes between trains, resulting in 64 trains an hour over the San Francisco Bay Bridge. Central Link is scheduled to operate with 4 minutes between trains or 60 trains per hour through the tunnel. Since each car is limited to 148 riders (per PSRC) light rail will be limited to less than 9000 riders per hour (rph).
An Oct 21st 2014 Seattle Times article reported more than 33,000 riders already use transit buses between Everett and Seattle during the 6-9 a.m. and 3-6 p.m. peak commutes. ST will likely route some of those buses to the Northgate station. However the resulting reduction in the number of buses between Northgate and Seattle will have essentially no effect on congestion. The only way for the $2.1B spent on extending light rail to Northgate to reduce congestion is to add more parking with bus connections to the station there. Yet none of the planning documents I’ve seen include any funds for doing so.
The 9000 rph Northgate light rail train capacity is 80% more than the 5000 rph capacity of an added highway lane (assuming single occupancy vehicles (SOV)). However, a 70-ft articulated bus can accommodate up to 119 sitting and standing riders. Thus fifty additional bus routes an hour could accommodate more than 5000 (rph), adding more capacity than the $2.1B Northgate extension.
The money budgeted for extending light rail could be used to add thousands of parking spaces and bus routes needed to reduce congestion. 5000 parking spaces along I-5 with bus connections into Seattle could be added each year for three years for probably less money than what ST will spend on Northgate extension during that period. At the end of the three years, the 15,000 parking spaces and the 50 added bus routes an hour, would add the capacity of an additional highway lane without increasing congestion. (While adding 15,000 parking spaces along I-5 may seem like a lot, developers are reportedly adding nearly 12,000 spaces in South Lake Union area.) Meanwhile the Northgate extension would still be years from initiating service.
ST could reduce the number of buses into Seattle without spending a dime on light rail extensions by adding a T/C near the University light rail station. The T/C would allow eastside 520 transit riders access to the 9000 rph light rail capacity into Seattle and Seattleites with light rail access to 520 bus routes to east side. Adding parking spaces and 520 bus routes from the east side would enable more eastside residents to use public transit. Direct bus connections from the UW T/C to Bellevue and Overlake T/C would enhance Seattleites commute to the east side.
Transit times into Seattle could be minimized by eliminating either all non-transit HOV traffic or +2 HOV traffic during peak commute on one of the two HOV lanes. The increased bus service in Seattle could be facilitated by converting 4th Ave into a 2-way, bus-only configuration, essentially creating a very long transit station. Doing so would provide space for each bus route to have one or two dedicated drop-off locations on one side for egress and pick-up locations on the other side for access. The limited number of stops would reduce transit times and the 4th Ave location would be more convenient for most commuters.
ST plans to extend light rail towards Federal Way and across I-90 to Bellevue and beyond are even less viable. The two extensions would presumably split the tunnel 9000 rph capacity, doubling the north end’s high cost/capacity ratio. Total weekday ridership on ST574, ST577/578, and ST590/595 routes into Seattle from the South averaged approximately 12,000 during 2014. Presumably most of those rode on one of the 40 buses the three routes provided during the peak 3-hour morning and afternoon commutes.
ST estimates their Angle Lake extension will attract “5400 riders daily coming and going”. Since ST is planning to add only 1050 parking spaces they must assume most of the morning and afternoon light rail commuters will be those who transfer from and to buses. Again, terminating bus routes at Angle Lake will have no effect on I-5 congestion and the only way to reduce congestion is to add both parking and bus routes.
As with the Northgate extension, a three-year program of adding 5000 parking spaces and bus routes each year could add the equivalent of an additional highway lane. Again, travel times could be reduced by requiring three riders for HOV lanes during peak commute and two-way 4th Ave "transit station" to expedite egress and access in Seattle.
The East Link extension is even more absurd. First of all, I-5 HOV congestion is a clear indication adding 4th lanes of the outer roadways won’t have the capacity to make up for the loss of the two center roadway lanes. Thus closure of the center roadway will increase cross-lake vehicle congestion. Second, the 4500 rph capacity will require 4½ hours each morning and afternoon to accommodate the 20,000 transit riders ST intends to transfer daily to and from light rail at the South Bellevue and Mercer Island stations. Not exactly a “magnet” for attracting additional transit riders.
Again adding 5000 parking spaces each year for three years will allow 15,000 eastside drivers to leave their cars near where they live. Some of the I-90 parking could provide access to Bellevue and Overlake T/C routes. Moving non-transit HOV traffic to the I-90 Bridge outer roadway will allow two-way, bus-only lanes on the center roadway with more than enough capacity to meet future growth requirements. Again egress and access will be facilitated by two-way 4th Ave. Return routes on I-90 could provide Seattleites with access to Bellevue T/C.
In conclusion the only way to reduce the area’s congestion is to increase public transit by adding parking and bus service to either light rail connections to where commuters want to go or for bus routes to those destinations. The problem in Seattle is light rail will never have the capacity to do so while the capacity of buses, and if needed bus-only lanes, far exceeds foreseeable demand. The fact that much can be done in three years with probably less money than would be spent on light rail during that period would seem to make it even more attractive.