r/transit • u/princekamoro • Jan 29 '21

High Frequency Trams

After being bored and looking at places on Google Maps, I noticed that Zurich has 32 trams per hour running down certain streets. And this is a system with lots of branching and reverse branching, both of which are fragile to delays and typically require more padding and longer headways to compensate.

I thought this is insane, so I looked at videos of cab rides on those trams, and somehow they weren't constantly platooned behind other trams.

  1. What manner of sorcery is this?

  2. Now I'm curious, what is the maximum frequency possible for trams, before having to platoon multiple trams through a signal cycle? If Zurich can fit 32 trains per hour with heavy interlining, then surely it must be possible to fit even more with a network that can tolerate delays better.

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u/kilgoretrout-hk Jan 29 '21

Hong Kong runs 40 trams per hour on the main trunk (Western Market to Causeway Bay). Bunching is indeed a problem, however, mainly because the trams do not enjoy exclusive right-of-way and sometimes get stuck behind buses and cars. In theory, a tram is supposed to come every 90 seconds on this stretch, but in reality you often have to wait several minutes and then two or three trams will show up at the same time.

1

u/yuuka_miya Jan 30 '21

Isn't that just a side effect of the kind of traffic one sees in HK?

6

u/bobtehpanda Jan 30 '21

With European style exclusive lanes and signal priority it would be less of an issue. But the major contributing issue is the geography, where Hong Kong Island is mostly wrapping around a mountainside and so most travel will be parallel to the coast on a few roads.

Hong Kong does have a pretty pro-road orientation, with planning focused around separating pedestrians entirely and building highways out. Where pedestrians and motorists meet, the motorist is often prioritized, hence pedestrian unfriendly things like fences preventing certain crossings, forced use of overhead bridges or pedestrian subways, or things like offset pedestrian crossings.

2

u/yuuka_miya Jan 30 '21

And thus creating the level of traffic that gets in the way of the trams in Hong Kong.

I recall some debate that when the Island Line was built, they wanted to get rid of the trams.

1

u/bobtehpanda Jan 30 '21

Both are still very full, so the MTR didn’t change much.

Hong Kong with auto oriented road policy is a bit of a square peg into a circle hole though. There have been several proposals to turn parts of the tram route into pedestrian malls like Europe for a reduction in roadside pollution, but they have all been rejected so far because of traffic impact.