Wednesday, January 21, 2015

Turning pockets

Over Christmas I was in Sydney. I was interested to see these separated cycleways on the corner of Kent Street and King Street. I have posted about the Sydney separated cycleways before, but had somehow missed seeing these turn pockets. 

It is the first I have seen on separated cycleways. I assume this must have high turning volumes as the King Street cycleway connects to the bridge over Darling Harbour. Unfortunately on New Year's day there was not much cycle traffic.

The operation of the cycleway is unfortunately constrained by the conflict with right turning traffic that needs to cross the cycleway. The cyclists therefore have a red signal until they activate the induction loops or pressure sensors in the pavements at the stop line.
Quite clearly this arrangement increases delay to cyclists. In the little time I stood there I observed a couple of cyclists ignoring the red bicycle signal and just going through with the general traffic.


In 2012 Bitzios Consulting undertook an assessment of thes signals amongst others. The phasing of the signals is interesting. There are two phases controlling movement on Kent Street:

  • cars going straight and turning right get a green signal as well as pedestrians (10 seconds red for beginning of Ped movements).
  • bicycles on Kent Street get a green signal while cars and pedestrians are stopped.

The cyclists signal phase apparently operates as part of the cycle during weekdays - getting 11% of the time (12 seconds). It only operates if called on evenings and weekends.
So cyclists are always stopped while cars run.  I would think that cyclists would have less delay and be better served if the signal phases were:

    • cars going straight get a green signal as well as pedestrians and cyclists.
    • cars going straight and turning right get a green signal - cyclists and peds stop.
    I don't know what the vehicle right turning volumes are, but I assume they are high - and hence the signal phasing. The Bitzios report recommended a  review of the allocated time to cyclist movements as cyclists often ignored the red signal when traffic volumes were low. I would be interested to find out whether alternative phasing as I suggest has been considered - especially when traffic volumes are low. Having the vehicle right turn as an actuated signal phase could significantly reduce the delay to cyclists.

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