See comments below, on Mastodon, Hacker News (51 comments), or LinkedIn (22 comments, 278 likes, 32k views)

Transport for NSW, the government agency which controls traffic signal timing in Sydney and elsewhere in NSW, has an excellent stated goal of increasing walking and cycling trips – and reducing pedestrian wait times at intersections.

However, there is no public data on traffic light timing in Sydney or NSW.

In the absence of traffic light timing data, and as we hold hope for it to become publicly available; the aim of Better Intersections is to crowdsource measurements and inform where positive changes could be made. You can add data yourself via a simple Google Form, and instructions are on the website about page.

Table of Contents

Better Intersections is a tool to record and visualise timing details for pedestrian and bicycle signals. It’s focused on Sydney & NSW, Australia, but is adaptable for anywhere in the world. This website is open source on Github (contributions welcome!), and the data is under an open license (ODbL license).

If you have ideas for improvements, please create a Github issue, comment below, email me at jake@jakecoppinger.com or message me on Mastodon (@jakecoppinger@aus.social).

It’s a work in progress! I’ve tinkered on it for a few afternoons and started working on it about two weeks ago.

This website bridges the excellent TfNSW Active Transport policy guidelines and pedestrians on the street themselves, allowing people on foot (and bicycle) to see their experience represented.

Why does the timing of pedestrian signals matter?

Transport for NSW, the government agency which controls traffic signal timing in Sydney and elsewhere in NSW, has an excellent stated goal of increasing walking and cycling trips – and reducing pedestrian wait times at intersections.

However, there is no public data on traffic light timing in Sydney or NSW.

In the absence of traffic light timing data, and as we hold hope for it to become publicly available; the aim of this project is to crowdsource measurements and inform where positive changes could be made.

This website bridges the excellent TfNSW Active Transport policy guidelines and pedestrians on the street themselves, allowing people on foot (and bicycle) to see their experience represented.

Increasing pedestrian priority and providing crossing opportunities at the right locations and along desire lines, reduces the risk of pedestrian injury at intersections by encouraging safer behaviours. Transport is currently rolling out measures at intersections to improve pedestrian priority in areas of high pedestrian activity. These measures may include automation of pedestrian crossings, reduced pedestrian wait times, provision of pedestrian crossings on missing legs and kerb ramps, where applicable.

— TfNSW Active Transport Strategy, page 30. Emphasis added.

Research has shown that 30 seconds is the longest a pedestrian will wait at a signalised crossings before attempting to cross against the ‘red man’. (Martin, A., 2006. Factors influencing pedestrian safety: a literature review (No. PPR241). Wokingham, Berks: TRL (Transport for London.)

From the above report:

Hunt, Lyons and Parker (2000) state that ‘Although no clear relationship has been established between pedestrian delay and casualties, a more balanced and responsive approach to the allocation of time at Pelican/Puffin crossings has the potential to make a substantial contribution to a decrease in pedestrian casualties as well as improving pedestrian amenity’. They point out that because pedestrians are more likely to become impatient when a red man continues to be shown during periods of low vehicle flow, the reduction of unnecessary delay for pedestrians should encourage pedestrians to use crossings correctly and reduce risk taking.

In 2020, people driving vehicles killed 138 pedestrians on Australian roads (Department of Infrastructure, Transport, Regional Development and Communications (2021) Fact sheet: Vulnerable road users, National Road Safety Strategy.)

But isn’t traffic light timing variable?

Sydney uses a system called Sydney Coordinated Adaptive Traffic System (SCATS) to control traffic signals, which makes use of many data feeds to control timing data.

Neither the inputs used, or the algorithm used to weigh the input data is public (as far as I know). This crowdsourced method of discrete measurements provides shows the output of the black box. In the case of outliers, multiple measurements (at different times of day/week) can be used to determine if the timing is variable.

Gehl Architects have a great methodology for measuring the overall impact of traffic light delays on pedestrians. At its most basic you walk along a street with two stopwatches;

• one you pause only when you’re walking;
• one you pause only when you’re waiting at a traffic light.

Divide one by the other at the end, and you have a single number that quantifies pedestrian delay walking along a street.

– Public spaces & public life: Sydney 2020, Gehl Architects, pg 142

The limitations of this method are that

• it cannot inform the exact problematic intersections;
• paths must be long enough to gather a large enough sample size to be statistically significant.

I’ve experimented with automating this method by recording a GPX (GPS) trace with a phone, uploading that file and getting a number instantly. Unfortunately the urban canyon effect (GPS signal loss caused by tall buildings) makes this method unreliable in cities, even with the remarkable sensor fusion on modern phones.

As with any of my projects, I am always open to collaboration. If you have any ideas, iterations or improvements, please drop me a line!

Technical details

This is a fairly simple Typescript app created using Create React App that I built in a few afternoons – please don’t consider it my finest code!

It is a static React app hosted on Cloudflare pages, and uses Mapbox GL JS to display the map (but could be easily updated to use Maplibre GL JS).

Google Sheets is treated as a backend (for simplicity using a Google Form for submissions), and the app makes use of OpenStreetMap node IDs as primary keys for intersections. This is definitely suboptimal but it’s quick to build – ideally I’d have a more custom form that is easier to use and doesn’t require a Google account – however using Google accounts for the form is a quick and easy method of minimising spam (and making it easy to identify) remove spam from a single person).

The OpenStreetMap API is used for looking up coordinates of OSM nodes and finding adjacent ways. There is currently one request per intersection made – this will not scale and I’ll likely need to cache the JSON (or hit an Overpass Turbo server instead).

The code is fully covered by Typescript types but doesn’t (yet?) have unit tests – it’s very easy to work with if you’re interested in tinkering with it!

Possible further work

• Adding a simplified version of the form
• Support OSM ways as the primary key rather than just nodes (useful for crossings across divided carriageways with multiple traffic light nodes per crossing leg)
• Tagging state roads and looking if these have longer wait times on average (probably)
• Scatter plot of crossing times vs number of lanes (as rough proxy for traffic volume)
• “sparkline” or other graphs of measurements for a given intersection
• Thinking about how to record relationships between intersections (ie. green wave/lack of green wave for pedestrians)
  • Using YOLOv3 or another off the shelf commodity computer vision model for recognising green/flashing red/red traffic lights for algorithm measuring cycle times

Related organisations

If you support better conditions for pedestrians and cyclists in Sydney/NSW, consider joining BetterStreets or 30 Please.

The post Mapping pedestrian traffic light timing in Sydney, Australia first appeared on Jake Coppinger.

Transport for NSW (TfNSW) has recently installed these around the Sydney CBD – a sticker on top of a pedestrian “beg button” explaining the button must be pressed between 10pm and 6am. Not only does this sticker look like it will last a few weeks, but if you have to explain how something works, it isn’t designed well.

The Active Transport strategy recently released by TfNSW specifically states (on page 12) that key initiatives for metropolitan and urban areas include:

prioritising pedestrian movements at key destinations, including prioritising pedestrians at traffic lights

and

upgrading existing paths and streets for better walking and cycling experiences

This begs the question – if a key TfNSW initiative is to prioritise pedestrians in urban areas, and we’re prepared to automatically give pedestrians a green light every cycle during the day when car traffic volumes are highest – why not prevent the confusion and remove/cover the buttons permanently?

Even more perplexingly – we previously had fully automated buttons and they were accepted (if not widely celebrated by pedestrian & cycling advocates), so why go backwards?!

Fully automatic crossings during the pandemic

From March 2020, pedestrian crossings across the CBD were automated so that touch contact wasn’t required.

At first, no physical alteration was made, however behaviour is hard to change so signs like this were installed:

Eventually blue covers were affixed so pressing the button wasn’t possible, while audio-tactile feedback of the PB/5 units was left uncovered to assist visually-impaired pedestrians.

Not only a sensible decision to reduce physical contact during a pandemic (especially when virus transmission was less understood), you probably aren’t surprised that automatically guaranteeing pedestrians a traffic light cycle makes walking easier and faster.

In 2007, Copenhagen firm Gehl Architects wrote a report for the city of Sydney evaluating public spaces, which specifically highlighted the Australian phenomenon of prioritising motor vehicles at street intersections:

Push buttons are a widespread phenomenon all over Australia and in Sydney, where all crossings are supplied with push buttons. The installation of push buttons is part of State Government law. Here you have to apply to cross the street and if you press the button in time the digital device will give you between 7 and 10 seconds of green light to step off the kerb, before the lights start to flash red to tell you to finish walking across the road. Red periods are long, often lasting between 60 and 90 seconds. This system takes the elderly, children and people with disabilities hostages since they will often not be capable of moving across the streets at the pace needed. It also sends a clear signal that cars have higher priority than people.

Sydney – Public Space Public Life, 2007, Gehl Architects

TfNSW removing automatic operation

On Friday the 16th of December, Transport for NSW announced:

From mid-December 2022 Transport for NSW is removing the push button hard covers but maintaining the automation of pedestrian crossings at traffic signals during daytime hours. This is to reduce overnight noise for local residents and allow for more efficient intersection operation for all users when activity is low.

TfNSW Argument 1: More efficient intersection operation

Requiring manual pedestrian button operation does improve intersection operation for cars at the expense of all other modes.

However, car traffic volumes are lowest at nighttime and congestion is decreased, so intersection efficiently does not need to be ruthlessly prioritised at those hours.

Remember, the TfNSW Future Transport Strategy states (page 9):

We will focus on getting more out of our existing investments, by reallocating road space to more efficient modes of transport like buses, walking, cycling and micromobility devices.

and

Our vision for transport in NSW “We will stabilise traffic levels in Greater Sydney to improve productivity and manage congestion, ensuring we accommodate growth without sacrificing quality of life.”

So we now have in writing that TfNSW say that they are no longer prioritising traffic volumes at the expense of all else.

Sydney aspires to be a city with a vibrant nightlife, and there are often large pedestrian volumes late into the night and morning. Pedestrians at these hours are also most likely to be under the influence of alcohol and if inconvenienced, may be more likely to “jaywalk”

TfNSW Argument 2: Reducing overnight noise

Noise from the pedestrian buttons “activating” when pedestrians are allowed to cross is an interesting argument. I can emphasise with urban dwellers in noisy environments (I currently live in Inner Sydney), but the automated signal map covers few (if any) streets with low rise residential buildings – this is the centre of the largest city in Australia after all!

The National Cooperative Highway Research Program study Accessible Pedestrian Signals: A Guide to Best Practices, has been adapted by the NCHR into this online best practice resource. It states:

• All devices respond to ambient sound, both for the locator tone and the WALK indication.
• APS [Accessible Pedestrian Signals] are sometimes turned off at night due to neighbors’ complaints about noise.

This implies that the the noise produced is lower at nighttime when there is less traffic noise, and there is already a precedent for pedestrian signals being turned off selectively at nighttime due to noise concerns.

Perhaps it makes more logical sense that only those pedestrian buttons that receive complaints should be set to manual overnight, with a prominent & permanent sign rather than a sticker.

Globally our little PB/5 units are so beloved that they’ve even been bestowed with a Grammy, their design so ubiquitous with simplicity that their main job is to almost blend into their environment, so why not let them and save them from our grubby fingers?

With a simple software update, that was already successfully tested during the pandemic, we can improve the walkability in the City of Sydney – and with any luck, everywhere else!

(…and after that, shorten cycle times and improve light phasing)

The post Sydney CBD is bringing back pedestrian “beg buttons” first appeared on Jake Coppinger.