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Show HN: Visualising real-time Sydney bus congestion with Marey charts

57 points| jakecopp | 3 years ago |jakecoppinger.com | reply

22 comments

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[+] jakecopp|3 years ago|reply
I built this side project to graph bus congestion in Sydney. Each line on the graph (a Marey chart) represents a bus completing its route (percentage) over time.
[+] jahnu|3 years ago|reply
Have things improved since I lived there in 2010?

The busses were constantly late (sometimes waiting an hour for a bus from Darlinghurst to the eastern suburbs on the weekends) Unbelievable noisy. Walking through the CBD on a workday morning was deafening. Engines with no acoustic dampening at all. Reckless drivers. Gave up trying to ride a bike. Just too dangerous and aggressive bus and car drivers :(

[+] bradrn|3 years ago|reply
I like this, as a Sydneysider who’s always been fond of Marey’s chart! However, I suspect there are some bugs: e.g. when I try 197, only two non-overlapping busses are shown despite the presence of several on the map, and 674 gives only a small line at the 100% mark and nothing else.
[+] jakecopp|3 years ago|reply
Thanks!

> However, I suspect there are some bugs:

Yep I wouldn't be surprised! The routes are statically generated so if there are updates (I'm not sure how often that happens) the progress lines won't be correct.

Thanks for the report though, I'll try looking into it when I have time.

[+] chewxy|3 years ago|reply
So I just discovered that there are multiple bus routes with the same number as the one that I usually would use. That's crazy.

(also the marey chart doesn't load for 425 or 412 or 433)

[+] jakecopp|3 years ago|reply
Is that true or according to sydneytransitgraph.com?

Might be a bug if the latter!

[+] dcw303|3 years ago|reply
Where is the data sourced from? I ask because of an experience I had recently when visiting Sydney. I was using transportnsw.info while waiting at a stop at Wynyard.

Eventually it told me that the bus I was waiting for had been and left, which seemed odd because I could see it still sitting idle further down the street. It eventually pulled up to the terminal about five minutes late, but the app did not update to reflect this.

[+] contingencies|3 years ago|reply
AFAIK a lot of dated bus systems have radio polling is based on signal loss. Under such a system, a stop sends out a weak stop-ID signal. If buses sit around the periphery of natural propagation they may 'drop in' and 'drop out' of a stop prematurely, which can trigger false readings. Unsure if that's how Sydney runs. Most systems now use GPS which is also susceptible to drift if not properly written (probably common). FWIW I had prior exposure to the RTA's traffic management systems in Redfern (PDP-11 still running!) ~2001, which also housed the State Emergency Service (SES) wireless system, but AFAIK no public transport.
[+] NIL8|3 years ago|reply
Googled "Marey chart" and "Marey diagram" and your site showed up on the front page. That's impressive as it looks like you only published a day ago!
[+] frob|3 years ago|reply
Busses are bosons; they tend to condensate.