Ask Phoebe: Redesign causes chaos at roundabout

King tides are likely to affect the Northwestern Motorway this week. Photo / Richard Robinson

Q. About 10 years ago the Blockhouse Bay roundabout was redesigned. Until then there were straight-ahead arrows on both lanes on Donovan St, suggesting that both lanes could be used to exit at Kinross St. As there are now no lane arrows there is a huge back-up of traffic trying to use the left lane to get to Kinross, and a few people using the right lane but circling the roundabout to get to Kinross. Could the arrows be repainted so both lanes could be used? Has anybody really tried to get this roundabout to work?
- Chris Thoreau, Green Bay.

A. Auckland City Council staff have done work here, and have even gone as far as digging out aerial photos dating back to 1993.

They say that there are lane arrows on the Donovan St approach and both approaches on Blockhouse Bay Rd. There are no lane arrows on the Kinross St approach and none on the Heaphy St approach, which makes sense, as it's only one lane.

But, the council says, the roundabout is confusing, not to say dangerous, and they intend to improve road markings and lane arrows within the next couple of months, subject to some design fine-tuning and a spot of decent weather.

Q. When exiting SH20 from the airport to Dominion Rd, there are two lanes for traffic turning on to Dominion Rd with no road marking to indicate that there is actually only one lane for through traffic ahead at the roundabout at Dominion Rd and Denbigh Ave. It is only when cars in the left lane reach the roundabout that drivers realise they are in the wrong lane for going down Dominion Rd towards the city, and attempt to merge, with close calls. When will the road marking be completed please?
- Ann Yandall, Auckland.

It's complicated, but more in the narration than the observance, I suspect. The council says that as you leave the Dominion Rd offramp and turn right on to Dominion Rd, there are three lanes of traffic. Two of these lanes turn right on to the Dominion Rd onramp, with the right-hand lane being a shared lane with straight ahead traffic. This shared lane continues on Dominion Rd to the roundabout as a straight-through lane.

Although the kerbside lane is marked straight, this lane changes to left turn only past the intersection of the eastbound offramp for Dominion Rd, approaching the intersection of Denbigh Ave.

The lane is deliberately marked straight before the intersection of eastbound offramp of Dominion Rd to prevent vehicles turning into the eastbound opposing traffic. Auckland City has recently marked another left lane arrow just past the eastbound offramp intersection to reinforce the dedicated lanes of Dominion Rd approaching Denbigh Ave. The council expects over time motorists will become familiar with the new layout and the problem may cease.

And, Ms Yandall, you will be pleased to note that the road marking has been completed at the Mt Albert Rd/Sandringham Rd intersection, so cars approaching Sandringham from the northwest now have a shared straight-through/right-turn lane.

* Unusually high tides this week, known as king tides, are likely to affect the Northwestern Motorway.

Take care between the Patiki Rd interchange and Rosebank Rd bridges, and do not attempt to use the cycleway 90 minutes each side of high tide.

The high tides will continue until Monday.