Newsletter #27 - 23 March 2017
If you haven’t lodged your submission on the indicative route of the Warkworth to Te Hana Road of National Significance, please send it to: firstname.lastname@example.org before the end of the month. Our last newsletter (http://bit.ly/2o2i64W) contains the details why the motorway connections for Warkworth aren’t good enough.
(NOTE: This newsletter contains a lot of graphics. To see an enlarged version, please view the gallery at the footer of this newsletter.)
If you thought Sunday’s gridlock was bad, the NZTA’s revised traffic projections don’t offer any good news. The motorway, Matakana Link, and Western Collector aren’t the magic cure that will eliminate congestion. In many ways, however, they will make matters worse.
The NZTA evidence for the Puhoi to Warkworth motorway included these charts:
What stands out to you? Besides the bizarre prediction that travel times won’t deteriorate between 2009 and 2026 (when the table below contradicts this), isn’t it odd that the motorway junction to the north of Warkworth would increase journey times between Warkworth and Wellsford at Holiday Start and between Wellsford and Warkworth at Holiday End?
Currently, Johnstone Hill Tunnels drip-feeds northbound traffic to Warkworth and the Hill Street intersection drip-feeds southbound traffic. Effectively, the Puhoi to Warkworth motorway moves the bottleneck from Johnstone Hill Tunnels to the motorway terminus north of Warkworth.
But the roundabout at the motorway junction does more than that. Northbound Warkworth traffic wanting to head to Wellsford must give way to southbound State Highway 1 traffic wanting to turn right towards the motorway. Conversely, southbound State Highway 1 traffic wanting to head towards the motorway must give way to motorway traffic heading towards Warkworth.
Considering Wellsford traffic southbound to Warkworth has its own sliplane, we conclude that the charts have their labelling back to front.
Minor mistake you ask? Throw in the revised projected traffic growth for Warkworth and the tables turn.
We’ve modelled the revised traffic projections and mapped a typical Sunday afternoon shortly after the motorway opens. With traffic growth, Holiday End peak this year will be like Sunday peak next year, which will be like morning peak the following year. Below is how it will look.
As you can see, the Matakana Link will be at gridlock and so will Great North Road (SH1) between the Hill Street intersection and beyond the motorway junction. Queues on Sandspit and Matakana Roads will stretch to Sharps Road.
“How can this be?” you wonder. Two reasons: First, traffic growth, and second, the design and proximity of intersections. Remember, 2022 is the earliest that the NZTA will start to look at fixing the Hill Street intersection. In other words, it is unchanged.
Ignoring Sandspit Road is decisive. For Sandspit Road, traffic almost doubles by the time the motorway is completed. That traffic squeezes through the confluence with Matakana Road at 400 vehicles per hour, then squeezes through the 100 vehicles per hour right-turning lane at the traffic lights, then proceeds through two more sets of traffic lights at Hudson Road and Matakana Link/Western Collector before it merges with southbound State Highway 1 traffic at the motorway roundabout junction. (Remember, at the Hill Street intersection, it only takes four vehicles on Sandspit Road wanting to turn left at the lights to hold up vehicles turning right - and vice versa.)
Matakana Road southbound traffic will predominantly be turning right onto Matakana Link, holding up northbound Matakana Road traffic. That traffic heading toward the motorway will form two queues at the traffic lights with Great North Road (the current SH1) and Western Collector. Being an x-shaped intersection, the most that will get through an hour would be 900 vehicles an hour, which is much lower than the 1200 per hour that will want to get through. Then the two lanes will merge into a one-lane sliplane to access the motorway, then merge with the southbound State Highway 1 traffic on the motorway.
Some Sandspit Road traffic will want to head towards the Matakana Link, which creates further congestion on Matakana Road.
Here is how Friday peak traffic looks:
Here, we see southbound State Highway 1 traffic giving way to Warkworth bound motorway traffic. Similarly, Warkworth bound motorway traffic must give way to northbound traffic from Warkworth. Matakana Link traffic gives way to northbound Matakana Road Traffic and southbound Matakana Road turning into Sandspit Road must give way. The short sliplane between State Highway 1 onto Sandspit Road means that traffic joins the southbound queue through the Hill Street intersection.
TWISTS AND TURNS
Remember, the new urban boundary will be Goatley Road. When the motorway received resource consent, the NZTA believed that 49 percent of motorway traffic would head to and from Warkworth. Since the Unitary Plan, that has increased to 68 percent.
The motorway roundabout’s latest design will not accommodate the 50 percent increase in motorway traffic, nor the demands that Warkworth will place on it. See for yourself:
Whilst there are one-lane slip lanes, there is only one lane to turn right from the motorway towards Warkworth, although there are two lanes for all the other right turns. Turning left from Warkworth towards the motorway involves a confusing merge into a slip lane or two lanes turning left on the roundabout itself. Those two lanes will have to give way to southbound State Highway 1 traffic wanting to enter the motorway. Imagine the chaos.
The queue that forms for southbound State Highway 1 traffic at Hill Street will be worse at the motorway junction as that traffic must give way to the predominant flow of Warkworth-bound traffic. The queue of northbound State Highway 1 at Hill Street wanting to turn right towards Matakana and Sandspit Roads will be much worse at the Matakana Link/Western Collector intersection due to the length of the left turn slip lane towards Matakana Link. Furthermore, the proximity of the Matakana Link junction with the motorway junction means that the queues will stretch back to and along the motorway.
Check out again the preliminary design for the Matakana Link/Great North Road intersection, which excludes the Western Collector connection.
Effectively, there is a dual carriageway (two lanes each way) between Hudson Road and the motorway junction. With the Hill Street intersection untouched, the Hudson Road lights becomes a bottleneck, right outside the proposed Pak ‘n Save.
This is just crazy. Sandspit Road traffic wanting to head south have the choice of three traffic lights (Hill St, Whitaker Rd, Woodcocks Rd) or three traffic lights and a roundabout to use the motorway south (Hill St, Hudson Rd, Matakana Link). Hardly enticing, is it?
DOESN’T ADD UP
The revised traffic projections seriously affect travel times. Here is the NZTA’s evidence for travel times presented at the Board of Inquiry:
Based on our modelling, which uses the revised traffic projections, journey times are worse for Warkworth, Eastern Beaches, and southbound State Highway 1 traffic – directly the result of the poor integration of the Warkworth connection with the motorway.
Circled are the figures that we dispute and our estimated journey times using the fastest route. The existing State Highway 1 was the fastest route for several of the Warkworth Town Centre and Eastern Beaches peak times, due to the Hill Street intersection not being favourable for right-turning traffic out of Sandspit Road onto the current State Highway 1.
What should most concern the NZTA is that the poor connection with Warkworth affects the feasibility of the whole motorway project. In the business case for the motorway (http://bit.ly/2kUWOIh), the benefits marginally exceed the costs. Since then, the construction cost of the motorway has increased to $709.5m and we estimate that the benefits of the project have reduced to $555.45m. See for yourself:
Such a situation could have been avoided if the NZTA provided Warkworth with reasonable connections to the motorway and doubled the capacity of the Hill Street intersection. Instead, look at the mess they have created.
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Account Name: “FixHillStreetNow Action Group” Bank Account Number: 12-3095-0042062-00.
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