An article in yesterday’s Herald highlighted a few of the worst spots across Auckland when it comes to congestion:
The section of the Southern Motorway which merges with the Ellerslie Panmure Highway is the most likely to suffer traffic delays, according to a traffic monitoring company.
The SUNA Traffic Channel analysis of major metropolitan roads also revealed the top six worst areas in New Zealand were in Auckland.
The company took speed and vehicle data from thousands of probe vehicles earlier this year to make the assessment.
The Southern Motorway’s South Eastern Highway exit was the country’s second most problematic.
The Great North Rd and Rosebank Rd exits on the Northwestern Motorway and the Tristram Ave and Constellation Drive exits on the Northern Motorway also suffered delays.
I’m not surprised that this section of the Southern Motorway comes up as the worst spot on the network. It’s not just the severity of congestion at this point which is a problem, but also the extent of the congestion timewise. It’s often stuffed on a Saturday, quite early in the afternoon, well after/before peak hours and so on.
The congestion, particularly northbound, seems to be caused by too many vehicles entering the Southern Motorway within a pretty short distance. Northbound merging onramps from the Southeast Highway (around 18,000 vehicles per day) and the Ellerslie-Panmure Highway (around 12,000 vehicles per day) really just dump too many vehicles onto the motorway within a short period of time for it to cope.
Data from here.
Despite the falling traffic volumes, NZTA still has a project in place to widen the section of northbound motorway between Ellerslie-Panmure and Greenlane, as noted in the article:
The NZ Transport Authority’s regional traffic manager, Kathryn Musgrave, said the agency had introduced a number of significant changes to ease congestion.
These included plans for an additional fourth northbound lane on the Southern Motorway from the Ellerslie Panmure onramp through to Greenlane.
I can probably live with such a project, as it seems there’s still a big problem even if volumes aren’t growing anymore. The real question is whether small, seemingly desperately required, state highway projects such as this one can still get funded when most of the budget is going on the Roads of National Significance along stretches of road with less than 10% of this section of motorway.