Green Lights More Often: Sydney’s Secret Traffic Signals Investigation

On 7 January 2018, Transport for NSW (TfNSW) pulled off something extraordinary. Overnight, traffic signals across the core of Sydney’s CBD were reprogrammed to show a green light more frequently – at least every 90 seconds. This is the remarkable story of the investigation and its results, which have remained a secret until recently uncovered through a GIPA request by Better Streets’ Jake Coppinger.

A green light every 90 seconds reduced the maximum wait time by a full 20 seconds (from the previous maximum cycle time of 110 seconds) for every pedestrian, cyclist and motorist.

In three months of monitoring, TfNSW’s documents report

• shorter pedestrian waits - up to 40% lower on some streets, with at least 18% lower at every measured site,

• bus performance that was unchanged or faster on most streets, including one case with ~3.6 minutes earlier arrivals, and

• by week eight, daily observation notes that the “Network worked well” in both peaks, suggesting traffic evaporation

So, with such impressive results, why doesn't TfNSW do it again? Why not for the whole inner city, as Clover Moore AO formally requested almost 7 years ago? Why not at other high streets across Sydney and NSW? Why isn't TfNSW writing papers on pedestrian wait-time reduction, similar to the recent award winning study from Manchester by Josef Whitfield?

Currently pedestrian deaths are increasing 27% year on year in NSW (rising over three times faster than occupants of motor vehicles). More people are killed by motor vehicles while walking in the City of Sydney than in any other LGA in NSW, but the council has no power to reduce speed limits or change signal operation.

Despite clear evidence that shorter signal cycles reduce wait times and improve safety for pedestrians, and in the words of TfNSW "Shorter wait times…could potentially reduce the risk of jaywalking (sic) and pedestrian crashes", TfNSW has not expanded this successful program beyond the CBD in the City of Sydney.

Along with reducing urban state road speed limits to 40km/h, why hasn’t TfNSW doubled down on this proven solution? For the long read on this TfNSW investigation …

Green Lights More Often: The Secret 2018 Study of Sydney’s Traffic Signals