The Dumbarton Corridor study, led by Plenary Americas in partnership with SamTrans, finds that the Glydways podcar technology that Plenary is marketing to be superior to other options studied. The study reached this finding despite the fact that presenters disclosed that there were no Glydways installations near the scale of the Dumbarton Corridor deployed yet anywhere in the world. Update: we’ve heard reports that there are no commercial deployments of Glydways anywhere at any scale.
The Glydways system provides 8-person automated vehicles that would come every 2-4 minutes. The other options analyzed in the study were bus rapid transit, light rail, and Caltrain-like electric commuter rail.
Logical gaps in the analysis
There were several logical gaps in the analysis that showed the Plenary Glydwys system coming out on top in the analysis, including whether small vehicles are a good fit for the corridor’s travel needs; how megaregional trips were considered, and the cost to maintain the system.
The presentation did not report how the 8-person system would handle peak commute crowds, or what peaking assumptions were made for post-Covid travel. This sort of automated guideway system with small vehicles is common for airport circulation, where there is a steady stream of passengers throughout the day. But where there are large peak period crowds, it is helpful to have larger vehicles, or there could be long lines that build up as people board small vehicles. Before Covid, the Dumbarton corridor had heavy rush hour traffic during peak commute times in the peak direction.
Also, if we understand the Dumbarton presentation correctly, the study did not analyze ridership from the 21-county megaregion, even though the commuter rail technology would be a good fit to bring in riders with megacommutes who are coming from the Central Valley or Sacramento. The rationale given at the meeting was that the study used the 9-county model from the Metropolitan Transportation Commission. Meanwhile, the Link21 study for a second transbay rail crossing parallel to the BART tube between San Francisco and Oakland is explicitly considering the benefits of that project for long megaregional trips.
Conventional electric rail like electrified Caltrain would provide better integration with long-distance service for megacommuters.
Another logical gap in the analysis is the operating costs. The presenters said that the cost assumptions for operations were drawn from a 1970s podcar system deployed at a university campus in Morgantown, West Virginia. The operating and maintenance costs of the system will have a much higher level of uncertainty than systems that have other deployments to compare to. Also, the lack of deployments adds to the risk – Morgantown has been on the hook to maintain a custom-developed system that has no market for replacement parts.
The Plenary/Glydways relationship
Plenary has also been marketing the Glydways technology in San Jose, where it is being proposed for the Airport Connector from Diridon to Mineta Airport
The Plenary Group is an international firm that deploys roadway and transit systems around the world, and were brought in by Facebook in 2018 in a partnership with SamTrans to explore options for Dumbarton Rail. When Facebook stepped back during Covid, Plenary took the lead on the study.
Glydways technology is also being proposed for South San Francisco to connect the Caltrain station to South City’s bayside office parks. It’s not clear whether Plenary is involved in the South San Francisco engagement.
The study is expected to come to the SamTrans board for review in May or June.