Seattle has plenty of hills and waterways which makes a subway system attractive in comparison to road-based solutions. But even a subway needs to worry about steep hills and water unless you’re willing to spend a ton of money building deep stations and maintaining escalators and elevators. This issue helped kill the First Hill Link station in 2005. Instead of deep stations or building huge ramps or bridges, it might make more sense for Seattle to focus on building a fast and efficient subway spine and use urban gondola technology to scale our hills branching out from that spine.
Gondola lines would run continuously using electric power and less labor than a subway, bus or streetcar while also not competing with existing roadways. There are other cities with similar geography which have already proven this technology. In particular in already densely populated neighborhoods, gondola lines are far easier to build and require less housing displacements than elevated lines. Gondola stations require a smaller footprint and therefore disruption than underground subway stations, and the stations can even get integrated into other buildings. Recent projects even integrate the gondola station into both rail and bus stops.
