KEY POINTS:
Heavy trucks are unlikely to be allowed back on the Auckland Harbour Bridge outer clip-on lanes, a senior Transport Agency official indicated yesterday.
Acting regional manager Tommy Parker stood by an earlier comment that it may be possible to reopen the lanes to trucks weighing 13 tonnes or
more for up to 15 years, once a $45 million structural upgrade is completed by the end of 2010.
But he believed that was unlikely, following a design assessment that the bridge would reach its "safe load capacity" in 10 to 20 years in the absence of restrictions on heavy vehicles.
"My suspicion is that, after consultation with the truckies, we will probably all agree the best thing is we retain some restrictions from day one."
Mr Parker noted that the estimated time before reaching safe load capacity did not directly equate to the longevity of the bridge.
He confirmed advice given to the Auckland Regional Transport Committee and campaigners for walking and cycling links across the bridge that adding infrastructure for those would mean an automatic requirement to restrict heavy traffic.
"If we put in a walking and cycleway we would have to enforce restrictions from day one," he said.
"Without the cycleway we can go unrestricted for up to 15 years, and then put on restrictions."
Transport committee chairwoman Christine Rose says the agency should consider giving walkers and cyclists a fair share of the existing bridge, if it felt unable to increase loads by adding new structures, and has called for better use of Auckland's wider transport network to delay any need for a $4 billion set of harbour tunnels in 20 to 40 years.
Auckland Road Transport Association executive member Chris Carr acknowledges that completion of the western ring route as an alternative passage to Northland would remove some pressure from the harbour bridge, but has asked whether Mrs Rose would pay extra cartage costs for deliveries to North Shore City.
Mr Carr confirmed that his members were coping adequately with existing restrictions on the bridge, on which heavy trucks were banned from both northbound clip-on lanes while the structural upgrade was taking place below them, and on the outer southbound lane - which was yet to receive extra "stiffening".
North Shore City representative on the regional transport committee Chris Darby said he appreciated Mrs Rose's frustration that the needs of walkers and cyclists were not being catered for, but believed plans for harbour tunnels should be accelerated by a need to remove freight from the bridge.
That followed advice from the Transport Agency that wear and tear caused by one laden 42-tonne truck equalled that of 10,000 cars.
A multi-party working party reporting to the Transport Agency and various Auckland councils has recommended four tunnels, two for motorway traffic and two for trains, with the cost estimated at $3.7 billion to $4.1 billion.