Why is North America always Light Rail and never Light Metro
I was just getting aggravated looking at Seattle’s recently connected Line 2 - it has 18 miles of new tracks, interlines with 15 miles of line 1 tracks, and ALL of it is grade separated - except one 6/10 of a mile section in Bellevue which should have been a viaduct or a tunnel.
In North America (at least Anglo NA - the Québécois seem to be doing just fine with their new REM) we tend to build more and more elaborate light rail systems with more and more heavy rail amenities, just to have the train make one or two left turns in busy intersections.
Toronto’s new Light Rail lines are exceptionally guilty of this, suffering from multiple personality disorder that they behave like heavy rail systems until they get stuck at a light.
I was wondering if anyone knows why. A light metro should not only be faster, safer, more reliable, less disruptive, and more convenient, it SHOULD be cheaper to build and operate. A quick look at most light rail systems shows that labor costs are the majority of expenses, even beyond debt servicing the original, overpriced lines. While track and maintenance personnel aren’t going anywhere, the bulk of this labor cost is operation, which light metros can do away with - hence cheaper. And per-mile costs of mult-line U.S. APMs - mostly at airports - suggest per-mile and station costs lower than modern light rail system.
The track cost is about the same (add rubber tired trackway, remove catenary). There is the need to add a tunnel or a viaduct here and there, but the stations should actually be cheaper - if the biggest barrier to service is labor costs, you can run shorter trains more frequently and build shorter stations as passengers dwell less. For instance, Seattle’s four-car stations could be two-car with a light metro, you can run trains more frequently. And if you’re thinking headways are still the bottleneck, rubber tired APMs have much shorter headways because the greatest limitation is the braking distance of a railcar. An APM stops like a bus, light rail stops like an unladen freight train.
And because rubber tires give you more wiggle room with grade, those viaducts and tunnels can be tighter and cheaper. As are the stations - by increasing frequency, you can reduce capacity on platform, which also tends to make stations much cheaper - exits and stairs capable of evacuating half as many people only need be half the size.
I have guesses here, but I was wondering if anyone with knowledge of this type of project knows why we build them this way.