The Issues

When our Network Optimisation team did its study of Onewa Road, they observed the following factors at the Birkenhead Avenue intersection were impacting congestion, safety and travel times:

Congestion on Onewa Road during the morning peak often spills over into the left-turn lane of Birkenhead Avenue by Zion Hill Reserve, which in turn backs up all of the traffic on that side. This could be improved by giving left-turning traffic an additional lane to queue.

Related to the above, when this area is heavily congested, buses and high-occupancy vehicles (vehicles with 3 or more people) turning from this direction get backed up as they're trying to enter the T3 lane. This mainly happens when cars from Highbury Bypass get stuck trying to move into the non-T3 lane before the T3 zone starts. This is especially impactful for buses because it can put them behind schedule and delay picking up customers.

On the other side of Birkenhead Avenue from Highbury Shopping Centre, only the right turn lane has directional lane markings. It's not always clear to people leaving the shopping centre which of the other three lanes are for which direction. The resulting confusion is a big contributor to blocked traffic and delays on this side. It also causes safety issues if people try to merge suddenly into the lane they need to be in or turn where they can't.

The current phasing setup of the traffic lights is no longer optimal for the number of vehicles that pass through the intersection, especially at busy times. A different phasing system would allow more vehicles to pass through more efficiently.

Additionally, we can manually optimise the traffic lights during busy hours, but we can't always predict when things will get so busy that we need to intervene. Improved technology could identify and adjust to sudden swells in traffic more quickly.

Long backups on Birkenhead Avenue from Highbury Shopping Centre can stretch all the way into the Hammond Place intersection and block the traffic from that street. This is particularly troublesome for customers because Hammond Place serves as the main access point to the shopping mall carpark.

The current pedestrian crossing setup at Birkenhead Avenue intersection is not ideal for people travelling in large groups. The countdown settings do not allow enough time for them to make it across together, which can result in stragglers still trying to cross after the countdown is up and cars are starting to move.

Additionally, the crossing facilities have worn down over the years and need to be brought to modern design standards. Many of the crossing ramps/islands are cracked and uneven as well as lacking proper accessibility features (such as tactile pavers for the visually impaired).

Our Proposed Solutions

To resolve these issues, we're proposing the below changes to the intersection. Some of these changes can be implemented around mid- to late 2025. Others require some additional investigation and planning and would most likely be implemented next year or later.

Changes We Can Deliver in 2025

These changes can be implemented this year. They would also help make way for future improvements.

Marking the middle lane from Birkenhead Avenue to Onewa Road as both a through and right lane. This would give drivers turning right from Birkenhead Avenue an additional lane to queue in at busy times.

Adding "Keep Clear" markings across the Birkenhead Avenue/Hammond Place intersection. The markings will help remind drivers to keep the intersection clear when there are lengthy backups so that vehicles coming from Hammond Place aren't blocked.

Solutions We're Considering for Beyond 2025

We need to do some additional investigation before we can deliver on these solutions, so our design plan won't be ready until at earliest next year. However, we welcome the community's feedback on these solutions we're considering. Your feedback will help us in shaping our plan.

Adding a second left-turn lane from Birkenhead Avenue (by Zion Hill Reserve) onto Onewa Road, giving left-turning vehicles two full lanes to queue. These turn lanes would flow seamlessly into their respective through lanes on Onewa Road, resolving many of the backup and safety issues related to merging with traffic coming from Highbury Bypass.

Additionally, having the second left-turn lane serve as a pocket T3 lane for buses/high-occupancy traffic going towards the motorway. When the T3 lane going towards the motorway is operating, the kerbside left-turn lane from Birkenhead Avenue would serve as a pocket T3 lane for buses and high-occupancy vehicles. This would effectively start the T3 lane at the Birkenhead Avenue turn bay. Starting it right before the turn to Onewa Road would resolve the issues these vehicles have trying to enter the T3 lane at its current starting point. At all other hours, both left-turn lanes would be open for all vehicles.

Having the middle through lane on Birkenhead Avenue from Highbury Shopping Centre also be a second right-turn lane onto Onewa Road. With this change, all vehicles would be allowed to turn right from the middle lane if they wish, and right-turning vehicles overall would have two full lanes to queue. This would create more space for right-turning vehicles to go on green and help reduce backups and delays at busy times.

Painting directional markings on all the approach lanes on Birkenhead Avenue from Highbury Shopping Centre. With this change, it will be clear to drivers early on exactly which lane is for which direction. Lane confusion will end, and unsafe turning/merging behaviours will significantly reduce.

Optimising and upgrading the traffic signals with pedestrian and queue detection technology. These technologies can sense when there are large queues of people on foot or in cars waiting on one side to go. When the signal changes for them, it will stay on green longer so that they have more time to get across safely.

Upgrading the pedestrian crossing facilities to modern standards for pedestrians of all ability levels. Upgrading the facilities would also benefit cyclists and other-active mode travellers by creating better quality places to cross safely, separate from vehicle traffic.

Next Up: Lake Road Intersection Traffic Light Changes

Click here or the button below to see the next set of changes we're proposing to optimise Onewa Road.