Traffic Signal Timing - Upper Kedron

Principal Petitioner Theon Kimball, Upper Kedron
Date Closed Sun, 20 Aug 2017 This epetition has ended
No. of signatures 142 signatures

(View signatures)

Residents draw to Council's attention the timing of the traffic signals at the intersections of Upper Kedron, Cemetery and Hogarth Roads, Upper Kedron. These traffic signals were introduced in October 2016 as a primary means to ensure the safety of pedestrians in the vicinity of St Andrew's Catholic School with the anticipated growth of the area.

Due to the road network layout of Upper Kedron, a majority of Upper Kedron residents enter and exit the suburb via Cemetery Road. Unfortunately however, the traffic signal timing design at this intersection appears to have only granted a secondary priority on the amount of green signal time to Cemetery Road and Hogarth Road. This has introduced an incredibly frustrating scenario for vehicles stopped at Cemetery Road and Hogarth Road looking to enter Upper Kedron Road. Vehicles are required to wait for the signal timing to sense their presence when there are regularly no other vehicles within the intersection. There appears to be at least two signal cycles that have been programmed: a regular cycle as well as an off-peak cycle.

The off-peak cycle has instantaneous recognition of vehicles stopped at a red light at any part of the intersection and immediately changes the lights for these present vehicles. However, the regular cycle has vehicles waiting at Cemetery Road sometimes for a period of around one minute. Then, when the green signal is given, it only lasts for around 10 to 20 seconds before turning red and then enforces another wait of 40 or more seconds for any vehicles who did not make it through the intersection. The amount of green light time is disproportionately in favour of through traffic of Upper Kedron Road.

It is requested to amend the traffic signal timing cycles at the whole Upper Kedron, Cemetery and Hogarth Roads intersection. Please look to have the off-peak cycle activated outside school zone times, Monday to Friday, 7am to 4pm. Even if this peak time was extended to 6pm it would be a significant reduction in the amount of red light time experienced by all users of this large intersection. In the regular (peak) cycle, please evenly split the green light time between Upper Kedron Road and Cemetery and Hogarth Roads.

Council response

Thank you for your petition requesting Council change the traffic signal timing cycles at the intersection of Upper Kedron, Cemetery and Hogarth Roads, Upper Kedron.

During the peak intersection travel times, the signals on Upper Kedron Road are operating in the coordinated mode, which allows the progression of traffic flows from adjacent intersections for through traffic. The coordination of these two signals during peak periods is necessary due to their close proximity and the expectation of through traffic to receive both green lights at the same time. The peak weekday morning period at this site is between 6.30am and 9am and the afternoon peak is between 3.30pm and 6.30pm. During these times, the signal phasing is set at 70 seconds which is the time taken for a full cycle of all vehicle and pedestrian movements.

The signals are also operating in the coordinated mode between 2.30pm and 3.30pm to cater for afternoon school times but with a shorter phase cycle of 60 seconds. Between 9am and 2.30pm on weekdays, and 8am and 7pm on weekends, the signals operate in coordinated mode with a cycle phase of 60 seconds. At all other times, the signals are operating in isolation mode and are controlled by vehicle loop detectors and pedestrian push buttons at the intersections.

Council has undertaken a detailed assessment of changes which could be made to the traffic signal phasing times. Following this assessment, timing changes at these two signalised intersections on Upper Kedron Road were made on 11 August 2017. As a result, the signal modes have changed from coordinated mode to isolated mode between 9am and 2.30pm on weekdays and isolated mode full-time on weekends. The isolated mode provides for better response to side road activations however the through movements on Upper Kedron Road will not receive green light coordination. The proportion of allocated time to each movement during the peak periods was found to be appropriate for the existing traffic conditions.

These timing changes will improve traffic flows for both Cemetery and Hogarth Roads. However, due to the close proximity of the two sets of signals, there is a need for them to be coordinated during peak weekday periods. Council will continue to monitor the traffic signal timings and apply changes where necessary.

Thank you for raising this matter.