12-11-2020, 03:08 PM
(12-11-2020, 02:52 PM)danbrotherston Wrote:(12-11-2020, 01:44 PM)taylortbb Wrote: I don't think that's a regulatory issue, that's the design speed of the track. ION phase 1 was all about reducing costs, and higher speeds cost more. Higher speeds require the track be straighter, which then requires more expropriation to straighten out the street, and so on. Or you use high-floor trains, which have significantly more flexibility with track geometry, but then you spend more on the stations.
There are perfectly straight sections of track where this is an issue. Slowing down around turns is reasonable but trains going straight along Northfield which last time I was there, were limited to 50km/h when surrounding traffic is limited to 60km/h and routinely exceeds 80km/h. They are separated from the road with fully controlled cross traffic, and the track is straight.
I don't know the exact issues on Northfield, but I've seen no evidence they're regulatory. OCS tension, track ballasting (for the section on the bridge), etc are all factors in the design speed. I agree it's annoying we only designed sections like that for 50km/h, but I still don't think it's regulatory. In the on-street sections they're regulated like streetcars, which are limited to the speed limit on the road.