6 ms·

Shining a light on the traffic signals of Sydney

50 points by jakecopp 3y ago

jakecopp 3y ago
Why do pedestrians in Sydney wait so long at traffic lights? I tried to find out the answer to this simple question and wrote a blog post of my findings - keen to hear your thoughts! I cover and share previously unpublished maps of signal timings, ODbL crowdsourced data from a open source website I built, how it costs $200 to buy data on a single intersection from the state government, details on signal programming in a proprietary plain text format, comparisons with best practice in Copenhagen and elsewhere, and what's in store for the future of traffic signals in Australia. Sydney is an important study location as it is the birthplace and development location of the Sydney Coordinated Adaptive Traffic System (abbreviated SCATS). Our government sells the system commercially to 30 countries and 200 cities around the world. We are quite literally exporting our biases. Countries that use Australia's traffic light system include New Zealand, Hong Kong, Shanghai, Guangzhou, Amman, Tehran, Dublin, Rzeszów, Gdynia, Central New Jersey, and in part of Metro Atlanta. [1] [1]: https://en.wikipedia.org/wiki/Sydney_Coordinated_Adaptive_Traffic_System https://en.wikipedia.org/wiki/Sydney_Coordinated_Adaptive_Tr...
- WarOnPrivacy 3y ago
  > Why do pedestrians in Sydney wait so long at traffic lights? They don't immediately cross when they get a walk signal?
  - jakecopp 3y ago
    They do - however it may be multiple minutes before they get a green walk signal unfortunately.
- throwaheyy 3y ago
  The city of Bellevue WA adopted SCATS a few years ago and driving there seems much more pleasant now. I can drive from downtown Bellevue to the Microsoft campus and often face only two red lights (if you know the area: crossing 20th St/Northrop Way and then turning left onto 156th Ave). Before you would be stuck at a bunch of red lights after the cross traffic was long gone. And almost every intersection now has permissive left turns where before you’d have to wait on an unnecessarily long red arrow. Don’t know how “dumb” their system was before but it’s been a big improvement.
  - interestica 3y ago
    What's the pedestrian experience like now compared to before?
    - throwaheyy 3y ago
      No idea. Bellevue is pretty suburban. Most people drive, it’s too spread out to walk many places.
quantified 3y ago
Excessive wait times with no danger is exactly why many of us on foot or bike will cross on a red light.
- 8n4vidtmkvmk 3y ago
  Figures this out pretty quick in Europe too. The locals don't wait. There's lots of times when there's clearly no cars coming. California also doesn't have jaywalking fines anymore I think, so... Yeah I'm just going to cross where/when I think it's safe. Which is also often NOT when it's green because cars be crazy.
- gonzo41 3y ago
  You usually don't get jay walking tickets in Australia. So most people just make adult decisions about their safety and manage for themselves.
  - Freedom2 3y ago
    Interesting. I was reading a HN comment last month about how Australians are 'disgustingly... devoted to following tiny guidelines' [1], so it's interesting to hear this aspect of freedom. I'm generally not inclined to believe that Australians manage for themselves, given the previous comment was first and takes precedence. 1: https://news.ycombinator.com/item?id=36457222 https://news.ycombinator.com/item?id=36457222
    - jay_kyburz 3y ago
      My Australian kids and 9 and 11 and we are very strict about waiting for the walk signal. Kids that age tend to walk around daydreaming, and just not great at working out how fast cars are moving. Crossing a busy road is literally the most dangerous thing they do. Another cultural observation, when living in Boston, my partner and I both found it strange that if you were standing on the side of the road, cars will stop and wait for you to cross, even if you were nowhere near a crossing or intersection. Cars seems to give way to pedestrians anywhere an everywhere. In Australia, cars wont stop for you unless you are at a crossing, and even then you need to make sure they have seen you. Cars zooming through a green light are not going to be looking for pedestrians walking against a red walk signal. The onus is on the pedestrian to not be hit, not the car to avoid the pedestrian. Update: Also.. its hard not to take this persons criticism personally, so when they say "the UK / Australia model where everyone obeys some stupid rule written on the wall over their own intelligence" I would just like to respond that is a combination of wanting to be polite and courteous to the sign poster, and intelligent enough to know we don't know everything, that the sign might be for our own safety. :)
getwiththeprog 3y ago
"As a result of these decisions, this results in the Sydney CBD effectively operating as a fixed time system during peak – that is, the phase lengths are very similar to the expected, pre-programmed length." Does this mean that for pedestrian walk times to be increased, there must necessarily be a reduction of cars within Sydney city? It is funny that the 'adaptive' system is flooded so it becomes a fixed system. The City of Sydney is going to have to recognise that to increase economic activity in the city there will have to be a reduction of cars to allow more persons access to this important economic space. Another big point I think is the idea of a wave of green lights so cyclists do not have to stop every block. Could a 'wave' idea also be used for cars to progress quicker - or will it just slow down other cars further? This is a really great analysis and wonderful blog post - keep up the great work.
- cdogl 3y ago
  FWIW City of Sydney has ample space for pedestrians and along with state governments has done a lot to reduce car traffic, including largely repurposing the central road running down it (George St) for light rail and pedestrians. There are also many large pedestrian only “malls”.
- 8n4vidtmkvmk 3y ago
  I've seen waves implemented on some streets in Canada (for cars). I don't know how you make it work in both directions though. Maybe you just do it in the direction with more traffic.
  - JohnFen 3y ago
    In my (US) city, they do this timing only on one-way streets.
- madeofpalk 3y ago
  In case you're not aware, and im not sure about the "economic outcome", but The City of Sydney pedestrianised the main street through the city about 6 years ago when they also installed light rail, and it looks like they're extending it even further. https://community.sydneycivil.com/george-street-south-pedestrianisation https://community.sydneycivil.com/george-street-south-pedest...
myself248 3y ago
I had never heard the term "scramble crossing" so I looked it up, and found this gem, from the former traffic commissioner of NYC: "As things stood now, a downtown shopper needed a four-leaf clover, a voodoo charm, and a St. Christopher's medal to make it in one piece from one curbstone to the other. As far as I was concerned — a traffic engineer with Methodist leanings — I didn't think that the Almighty should be bothered with problems which we, ourselves, were capable of solving."
- beachy 3y ago
  Also known as a "Barnes dance" crossing (in NZ at least)
golemiprague 3y ago
[dead]
eisvogel 3y ago
I've done low-level work in C++ with SCATS, about a decade ago. It was a challenging API to work with, not fully documented and a lot of strange timing "phenomena".
- jakecopp 3y ago
  Interesting - could you explain more about the strange phenomena and lack of documentation? I've heard there is still present issues with lack of documentation, and more experienced folk having left the development team.
- GianFabien 3y ago
  SCATS was originally based on LSI-11 (pizza-box sized PDP-11) hardware. I wouldn't be surprised if considerable legacy code still lurks in there. Don't know what the current hardware is - hope it's not Windows 3.11 PCs. (Don't laugh, a few years ago I was working with ATMs for a large bank, inside the ATMs were beige PCs running Windows 3.11).
  - russelg 3y ago
    Lots of the screenshots in the article show the software running on XP.
GianFabien 3y ago
Sydney's streets were laid out over a century ago. They barely coped with horse and carriage traffic. Now we have Pitt St Mall and George St is mostly closed for the trams. Many streets have been narrowed to allow for bicycle paths. So car, truck, taxi, ride-share, delivery van traffic has been funneled onto ever dwindling number of roads and parking has become extremely scarce. As a result congestion has gotten worse.
NoZebra120vClip 3y ago
Don't forget the most familiar sound of the PB/5 pedestrian button, which every emo kid in the world has known and loved since 29 March 2019. Groovy stuff, Australia!
wkat4242 3y ago
I love Sydney's pedestrian crossing call buttons. They make this 80s videogame sound when it's time to cross :) Well they did when I was there in the early 2000s.

50 points by jakecopp 3y ago

Why do pedestrians in Sydney wait so long at traffic lights? I tried to find out the answer to this simple question and wrote a blog post of my findings - keen to hear your thoughts! I cover and share previously unpublished maps of signal timings, ODbL crowdsourced data from a open source website I built, how it costs $200 to buy data on a single intersection from the state government, details on signal programming in a proprietary plain text format, comparisons with best practice in Copenhagen and elsewhere, and what's in store for the future of traffic signals in Australia. Sydney is an important study location as it is the birthplace and development location of the Sydney Coordinated Adaptive Traffic System (abbreviated SCATS). Our government sells the system commercially to 30 countries and 200 cities around the world. We are quite literally exporting our biases. Countries that use Australia's traffic light system include New Zealand, Hong Kong, Shanghai, Guangzhou, Amman, Tehran, Dublin, Rzeszów, Gdynia, Central New Jersey, and in part of Metro Atlanta. [1] [1]: https://en.wikipedia.org/wiki/Sydney_Coordinated_Adaptive_Traffic_System https://en.wikipedia.org/wiki/Sydney_Coordinated_Adaptive_Tr...

WarOnPrivacy 3y ago
> Why do pedestrians in Sydney wait so long at traffic lights? They don't immediately cross when they get a walk signal?
- jakecopp 3y ago
  They do - however it may be multiple minutes before they get a green walk signal unfortunately.
throwaheyy 3y ago
The city of Bellevue WA adopted SCATS a few years ago and driving there seems much more pleasant now. I can drive from downtown Bellevue to the Microsoft campus and often face only two red lights (if you know the area: crossing 20th St/Northrop Way and then turning left onto 156th Ave). Before you would be stuck at a bunch of red lights after the cross traffic was long gone. And almost every intersection now has permissive left turns where before you’d have to wait on an unnecessarily long red arrow. Don’t know how “dumb” their system was before but it’s been a big improvement.
- interestica 3y ago
  What's the pedestrian experience like now compared to before?
  - throwaheyy 3y ago
    No idea. Bellevue is pretty suburban. Most people drive, it’s too spread out to walk many places.

quantified 3y ago

Excessive wait times with no danger is exactly why many of us on foot or bike will cross on a red light.

8n4vidtmkvmk 3y ago
Figures this out pretty quick in Europe too. The locals don't wait. There's lots of times when there's clearly no cars coming. California also doesn't have jaywalking fines anymore I think, so... Yeah I'm just going to cross where/when I think it's safe. Which is also often NOT when it's green because cars be crazy.
gonzo41 3y ago
You usually don't get jay walking tickets in Australia. So most people just make adult decisions about their safety and manage for themselves.
- Freedom2 3y ago
  Interesting. I was reading a HN comment last month about how Australians are 'disgustingly... devoted to following tiny guidelines' [1], so it's interesting to hear this aspect of freedom. I'm generally not inclined to believe that Australians manage for themselves, given the previous comment was first and takes precedence. 1: https://news.ycombinator.com/item?id=36457222 https://news.ycombinator.com/item?id=36457222
  - jay_kyburz 3y ago
    My Australian kids and 9 and 11 and we are very strict about waiting for the walk signal. Kids that age tend to walk around daydreaming, and just not great at working out how fast cars are moving. Crossing a busy road is literally the most dangerous thing they do. Another cultural observation, when living in Boston, my partner and I both found it strange that if you were standing on the side of the road, cars will stop and wait for you to cross, even if you were nowhere near a crossing or intersection. Cars seems to give way to pedestrians anywhere an everywhere. In Australia, cars wont stop for you unless you are at a crossing, and even then you need to make sure they have seen you. Cars zooming through a green light are not going to be looking for pedestrians walking against a red walk signal. The onus is on the pedestrian to not be hit, not the car to avoid the pedestrian. Update: Also.. its hard not to take this persons criticism personally, so when they say "the UK / Australia model where everyone obeys some stupid rule written on the wall over their own intelligence" I would just like to respond that is a combination of wanting to be polite and courteous to the sign poster, and intelligent enough to know we don't know everything, that the sign might be for our own safety. :)

getwiththeprog 3y ago

"As a result of these decisions, this results in the Sydney CBD effectively operating as a fixed time system during peak – that is, the phase lengths are very similar to the expected, pre-programmed length." Does this mean that for pedestrian walk times to be increased, there must necessarily be a reduction of cars within Sydney city? It is funny that the 'adaptive' system is flooded so it becomes a fixed system. The City of Sydney is going to have to recognise that to increase economic activity in the city there will have to be a reduction of cars to allow more persons access to this important economic space. Another big point I think is the idea of a wave of green lights so cyclists do not have to stop every block. Could a 'wave' idea also be used for cars to progress quicker - or will it just slow down other cars further? This is a really great analysis and wonderful blog post - keep up the great work.

cdogl 3y ago
FWIW City of Sydney has ample space for pedestrians and along with state governments has done a lot to reduce car traffic, including largely repurposing the central road running down it (George St) for light rail and pedestrians. There are also many large pedestrian only “malls”.
8n4vidtmkvmk 3y ago
I've seen waves implemented on some streets in Canada (for cars). I don't know how you make it work in both directions though. Maybe you just do it in the direction with more traffic.
- JohnFen 3y ago
  In my (US) city, they do this timing only on one-way streets.
madeofpalk 3y ago
In case you're not aware, and im not sure about the "economic outcome", but The City of Sydney pedestrianised the main street through the city about 6 years ago when they also installed light rail, and it looks like they're extending it even further. https://community.sydneycivil.com/george-street-south-pedestrianisation https://community.sydneycivil.com/george-street-south-pedest...

myself248 3y ago

I had never heard the term "scramble crossing" so I looked it up, and found this gem, from the former traffic commissioner of NYC: "As things stood now, a downtown shopper needed a four-leaf clover, a voodoo charm, and a St. Christopher's medal to make it in one piece from one curbstone to the other. As far as I was concerned — a traffic engineer with Methodist leanings — I didn't think that the Almighty should be bothered with problems which we, ourselves, were capable of solving."

beachy 3y ago
Also known as a "Barnes dance" crossing (in NZ at least)

golemiprague 3y ago

[dead]

eisvogel 3y ago

I've done low-level work in C++ with SCATS, about a decade ago. It was a challenging API to work with, not fully documented and a lot of strange timing "phenomena".

jakecopp 3y ago
Interesting - could you explain more about the strange phenomena and lack of documentation? I've heard there is still present issues with lack of documentation, and more experienced folk having left the development team.
GianFabien 3y ago
SCATS was originally based on LSI-11 (pizza-box sized PDP-11) hardware. I wouldn't be surprised if considerable legacy code still lurks in there. Don't know what the current hardware is - hope it's not Windows 3.11 PCs. (Don't laugh, a few years ago I was working with ATMs for a large bank, inside the ATMs were beige PCs running Windows 3.11).
- russelg 3y ago
  Lots of the screenshots in the article show the software running on XP.

GianFabien 3y ago

Sydney's streets were laid out over a century ago. They barely coped with horse and carriage traffic. Now we have Pitt St Mall and George St is mostly closed for the trams. Many streets have been narrowed to allow for bicycle paths. So car, truck, taxi, ride-share, delivery van traffic has been funneled onto ever dwindling number of roads and parking has become extremely scarce. As a result congestion has gotten worse.

NoZebra120vClip 3y ago

Don't forget the most familiar sound of the PB/5 pedestrian button, which every emo kid in the world has known and loved since 29 March 2019. Groovy stuff, Australia!

wkat4242 3y ago

I love Sydney's pedestrian crossing call buttons. They make this 80s videogame sound when it's time to cross :) Well they did when I was there in the early 2000s.