Munich vs ST3

When the ST3 measure was approved by voters in 2016, Sound Transit had only some rough ideas about how to deliver the promised transit improvements. Cost estimates were done based on comparable projects. Now that the plans are getting more specific and Sound Transit can do bottoms-up estimates, it turns out that the projects are more complicated, and cost is quite a bit higher. That's certainly the case for the West Seattle extension, but I expect similar increases to happen for the Ballard/downtown section. While I was recently traveling to Munich, I was wondering whether the region could learn some from their transit system.

Munich has an extensive S-Bahn regional rail network operated by DB (Deutsche Bahn). All lines converge in the city's center through a single tunnel. For the 1972 Olympics MVG (Muenchner Verkehrs Gesellschaft), the city's transit agency, decided to build a separate U-Bahn subway network which by now covers all major parts of city, either underground or elevated. It uses third rail power to allow for smaller tunnel diameter and reduced cost.

While the U-Bahn kept expanding within the city, the S-Bahn kept reaching more suburbs. When the S-Bahn's daily ridership passed 800,000, DB decided a second parallel tunnel was necessary. Such undertaking turned out to be quite a challenge; the cost and timeline has kept slipping. Currently the tunnel is slated to open in 2037. In the meantime, the transit agency is making further improvements to their signaling system to allow even more trains to travel through the existing tunnel.

Sound Transit had chosen light rail technology to allow for affordable at-grade tracks. While this may be important for long stretches in the suburbs, for urban applications Sound Transit has avoided at-grade tracks to avoid interference with other modes. So maybe Sound Transit should consider a more appropriate technology for its urban lines akin to U-Bahn technology - such as Ballard/SLU - and keep it separate from the existing light rail. That would also allow for an automated line with shorter more frequent trains, and therefore smaller stations such as the Skytrain in Vancouver (or Honolulu, Montreal, Copenhagen, etc).

Berlin had contemplated expanding some of their U-Bahn lines, but after cost and carbon footprint estimates came in, decided to look at alternatives, first at trams, now at the TSB maglev elevated system.

Munich did not consider building a second tunnel until ridership exceeded 800,000. Instead they upgraded their signaling system to accommodate lead times as short as 90 seconds. Frankfurt recently contracted with Siemens to increase train frequency in their central tunnel, too. If cost and time line for a second downtown tunnel in Seattle escalates, Sound Transit may need to consider the same. it may enable Sound Transit to meet ST3's ridership commitments without incurring the cost, risks and delays a second tunnel would.

Building light rail lines is quite involved. Sound Transit usually acquires an 80 foot corridor to build an elevated line. It avoids running elevated above a road. Construction reminds me of a highway bridge but instead of asphalt, steel tracks are laid. Instead of safety guardrails, safety fencing or acoustic panels are installed. Instead of light poles, you install overhead wires and electrical systems. Yes, avoiding road alignments will reduce traffic disruptions, but requires many property acquisitions. Residents and employers will have to find new locations and communities and their resources are disrupted.

Mexico City and Paris are building urban gondola lines. Bangkok is building monorail. Berlin and Nuremberg are looking at TSB maglev train lines to build elevated guideways faster and with less disruption and cost by using prefabricated modules and smaller stations, and operating more frequently due to automation. Sound Transit may need to look at adopting modern transit technologies to deliver the promises they made to voters within the available budget and timeline.

Any of these technologies allow for greater climbing capabilities than steel rails. Sound Transit had dismissed an alignment through West Seattle along Genesee Street with a station close to Delridge Community Center. With light rail it would require a deep bored tunnel through Pigeon Point which would increase cost and risk. With alternative systems you could go over Pigeon Point or do a shallow cut or cut-n-cover tunnel and still climb up towards Avalon Way. The TSB system allows for longer distances (up to 120 feet) between support columns than our monorail. Columns can be placed in the center of a road or straddle a road. The former may require a lane reduction while the latter may only reduce some parking. Ease of construction and more guideway flexibility would provide for greater flexibility to integrate transit into our existing road network. Connecting buses could stop right under a station rather than having to get off the road to a separate station which speeds up transfers.

Soon the Board will need to decide how to address the upcoming challenges. During the pandemic the Board mostly pushed out the construction schedule to get a chance to collect more taxes (realignment"). I hope this time staff will be more creative and use more appropriate transit technologies to deliver the transit solutions they promised voters. Seattle is not as much focused on downtown but SLU, Capitol Hill, First Hill and even Bellevue. Therefore Ballard/SLU should be a priority and not West Seattle. Rather than assuming the risks associated with building another downtown tunnel, we should increase the capacity of our existing tunnel by improving signaling and improve station circulation.