As Frank initially covered on Saturday, Sound Transit has released a slide deck summarizing a new study of possible high-capacity transit options in a large, roughly L-shaped area connecting downtown, West Seattle, White Center, Burien, Tukwila, and Renton. Sound Transit’s study doesn’t restrict itself to a single corridor, particularly in the West Seattle/White Center part of the study area. Instead, the agency presents a wide variety of options for HCT throughout the entire study area, parts of which could presumably be mixed and matched to form more refined options, just as SDOT and Sound Transit intended with the first public draft of their Ballard proposals (later refined).
Everything from slow, low-cost semi-BRT to long, extravagant light-rail tunnels is on the table, and the route between Burien and Seattle could serve Morgan Junction, South Park, or just about any neighborhood in between. To avoid duplicating Frank’s post, I won’t resummarize all of the options here—I’ll just reprint Sound Transit’s table, and add more specifics where needed below. (Please note that ST made a typo on Option A5 in this table — it is LRT, not BRT.)
As could be expected in an area as confusing and topographically difficult to serve as this one, the options reveal competing, dramatically different ideas about the goals of major transit investments. And Sound Transit’s evaluations of each option, which are on the last page of the study presentation, tip the agency’s hand about which goals its planning process is designed to serve first. While it is wonderful that ST has finally given detailed study to an area it more or less ignored for many years, I would argue the agency is much too focused on new and speculative regional connections, and not focused enough on speeding up existing trips with extremely high demand. As a result, I think it didn’t put together the best combination from among its menu of options. Fortunately, it’s pretty easy to mix-and-match our way to the best option. More below the jump.
The “tell” of excess focus on new regional connections is the heavy emphasis on the east-west Burien/Renton corridor. To put it mildly, this is not a corridor where existing demand suggests a need for true high-capacity transit. Route 140, currently serving this corridor, sees 3500 daily riders today. (In a few weeks Route 140 will be replaced by the RapidRide F Line. If ridership improves consistently with past RapidRide conversions, it may become 4500 or so daily riders.) Some of Route 128 will also be improved by this east-west corridor, helping another 2500 or so daily riders (those south of Alaska Junction).
By contrast, the Burien-Seattle portion of the corridor has the potential to replace most or all trips on the RapidRide C Line; Route 21 local and express; Route 55; Route 113; Route 116; Route 120; Routes 121, 122, and 123; Route 125; Route 131; and, depending on the routing ultimately chosen, possibly Route 132. These lines, added together, represent somewhere between 28,000 and 34,000 existing daily riders, depending on how you do the math. In other words: one of these corridors is not like the other.
ST would argue that the 140 comparison is inapt, because downtown demand from Renton, Southcenter, and Tukwila will also shift to the HCT line. Depending on how you count downtown demand, that could add another 15,000 or so existing daily riders to points along the south half of the line. The ridership estimates for options A3, A5, B2, and B4 seem to have those riders baked in, and ST’s presentation refers in multiple places to serving downtown demand. The two options without a somewhat speedy downtown connection from Renton and Tukwila, A4 and C5 Hybrid, are dinged in ST’s evaluation for “poor rider benefits.”
But ST’s assumption that people will use these options to get downtown from Renton or Southcenter seems unrealistic. The fastest of ST’s options assume travel time of roughly 40 to 45 minutes between Renton and downtown. This is between 8 and 15 minutes slower than existing Metro Route 101. Similarly, travel times between Southcenter and downtown are likely to be significantly slower than Metro Route 150. Even with the huge speed advantage of grade-separated HCT, a West Seattle route is just not an efficient way downtown from those points. And a transfer at Tukwila to Central Link is not going to be significantly, if at all, faster, given the transfer penalty and Central Link’s indirect routing. I think it’s fair to assume that a Renton-Burien HCT link will serve almost exclusively crosstown ridership — ridership which is simply not in the same order of magnitude as north-south demand between Burien, West Seattle, and downtown.
There is one option, C5 Hybrid (pictured above), which appears to recognize this reality. C5 Hybrid would build excellent HCT to many West Seattle neighborhoods with strong transit demand. It would invest in the Burien-Renton corridor commensurately with demand there, retaining surface BRT but substantially streamlining the baroque RapidRide F Line route. Still, C5 Hybrid has significant weaknesses. Unlike other options, it does not improve Burien-downtown service, and could not replace Route 120 or the Burien freeway expresses. It would also not serve Delridge, and not provide any good transfer point for Delridge riders. In West Seattle, it would be elevated rather than tunneled—likely generating much local controversy.
But a combination of the ideas from C5 Hybrid and A5, the most expensive light-rail option, can solve the problem.
I would urge ST to study a rail line similar to A5 between downtown and Burien (as in the partial picture of A5 at right), with a tunnel between the end of the West Seattle Bridge and White Center and surface running in exclusive lanes between White Center and Burien. But between Burien and Renton, I would suggest replacing expensive rail with the much cheaper BRT option from C5 Hybrid, matching investment with likely demand and recognizing the reality that crosstown HCT without transfer options cannot hope to compete with express bus service directly from Renton or Southcenter to Seattle.
With part of the savings from eliminating rail between Burien and Renton, I would urge ST to add a station at north Delridge to the A5 rail line, allowing bus riders in the very busy Delridge corridor an easy and fast connection to rail. With that addition, you would have a line functionally very similar to the one I suggested in December, that would serve the vast majority of downtown demand from west of the Duwamish, and a substantial amount of intra-West Seattle demand as well.
Of course, even with savings, the financial case for a West Seattle rail line remains problematic. Based on the options from ST’s study, I think my A5+C5 suggestion would probably cost between $5.5 and $7 billion, for a likely total of 50,000 or so daily riders. As I discussed in that December post, the cost per rider associated with this option—and, frankly, any other West Seattle option worth doing—is likely to be higher than for Central Link, U-Link, North Link, Ballard Link, or even East Link. Meanwhile, West Seattle already has the most effective quasi-BRT in the city (counting both RapidRide C and Route 120), which could get even more effective yet with a few strategic investments: a last-mile solution inbound into downtown, much more aggressive TSP along California and Delridge, bus lanes in and around White Center, and possibly priority ramps between the West Seattle Bridge and Highway 99. Given the persistent capacity shortage on existing Duwamish crossings, and extremely strong growth projected in West Seattle, a new line and its additional capacity could still be worth the cost — but both Sound Transit and voters in ST’s Seattle subarea should consider the cost carefully when looking at these options.