Auckland Harbour Bridge

Early crossing proposals As early as 1860, engineer Fred Bell, commissioned by North Shore farmers who wanted to herd animals to market in Auckland, had proposed a harbour crossing in the general vicinity of the bridge. It would have used floating pontoons, but the plan failed due to the £16,000 cost estimate ($2.4 million, adjusted for inflation as of 2025). Additional structures for a bridge crossing the harbour were proposed in 1927 and 1929. Two Royal Commissions in 1930 and 1946 were held on the viability of a bridge crossing the Waitemata. Design approval Prior to the opening of the bridge in 1959, the quickest way from Auckland to the North Shore was by passenger or vehicular ferry. The fastest way via car was through the Coatesville-Riverhead Highway The decision to reduce the bridge in this way has been called "a ringing testament to [...] the peril of short-term thinking and penny-pinching". The large steel girder sections were partially pre-assembled, then floated into place on construction barges. One of the main spans was almost lost during stormy weather when the barge began to drift, but the tugboat William C Daldy won a 36-hour tug-of-war against the high winds. The bridge was constructed from opposing sides of the harbour. The southern section was cantilevered, until both sides were joined in March 1959. the bridge was officially opened on 30 May 1959 by the Governor-General Lord Cobham. An open day had been held, when 106,000 people had walked across. The opening period was extremely busy, despite the poor weather in Auckland experienced in June 1959. The hollow girder design by Freeman, Fox and Partners design was unprecedented in New Zealand, and fell outside the 1950s building codes in New Zealand. As the sections were manufactured by a Japanese company, this led to the nickname 'Nippon clip-ons'. The selection of the company was considered a bold move at the time, barely 20 years after WWII and with some considerable anti-Japanese sentiment still existing. The costs of the additions were much higher than if the extra lanes had been provided initially. ==Operations and uses==

moving the barrier for the afternoon/evening traffic rush Tidal flow A "tidal flow" (dynamic lanes) system is in place, with the direction of the two centre lanes changed to provide an additional lane for peak-period traffic. During the morning peak, five of the eight lanes are for southbound traffic; in the afternoon, five lanes are northbound. At other times, the lanes are split evenly, but peak traffic has become proportionately less – in 1991 there was often a higher than 3:1 difference in directional traffic; in 2006, this had dropped to around 1.6:1. The bridge has an estimated capacity of 180,000 vehicles per day, and in 2006 had an average volume of 168,754 vehicles per day (up from 122,000 in 1991). In March 1982, the Ministry of Transport and Auckland Harbour Bridge Authority conducted a week-long traffic blitz in an attempt to improve the standard of driving. Of the 600,000 vehicles which used the bridge over this period, 6,000 were stopped, with half of those receiving a ticket and the rest cautioned. A second blitz was held for 36 hours a few weeks later. For many years, lane directions were indicated by overhead signals. In the late 1980s, a number of fatal head-on accidents occurred when vehicles crossed lane markings into the path of oncoming traffic. In 1988, feasibility investigations began into the use of a movable lane barrier on the Auckland Harbour Bridge. In July 1989, the government approved the project. Moveable barriers In November 1990, a moveable lane barrier (MLB) system, 2.2 km long, became operational. At the time, it was the first concrete safety barrier system of its kind installed on a bridge with a significant grade (5%) and horizontal curvature. Two barrier transfer machines were built in Auckland, with key components sourced from the USA. Capable of travelling at 30 km/h on the road unladen, and 3 km/h when shifting barriers. The new machines can move the barrier in half the time the old ones did, taking 20 minutes instead of 40. Tolling (1959–1984) The bridge was funded by government-backed loans, in 2018) per car but were reduced to 2/- (2 shillings: approximately $4.47 Tolling was later made north-bound only before being discontinued on 31 March 1984, and the booths were removed. The toll system was removed as the cost of collection began to outweigh the profits. Event management As part of large events such as the Auckland Marathon, normal motorway restrictions on access are sometimes relaxed. December 2011 was the first time that cyclists were officially allowed on the bridge, for a race / community cycling event organised by Telstra Clear, Auckland Transport, NZTA and Cycle Action Auckland, also allowing cyclists on the Northern Busway. Up to 9,000 riders were protected by 160 stationary buses used as a 'guard of honour' between the bridge end and the Northern Busway from traffic on the rest of the motorway. Utilities The bridge supports several utility services, including water and gas pipelines and fibre-optic telecommunications cables. Transpower reached agreement with Transit in 2005 for the installation of cable supports beneath the bridge for a future cross-harbour power cable. In 2012, Transpower installed three 220,000-volt cables on the bridge, linking Hobson Street substation in the Auckland CBD to the Wairau Road substation on the North Shore. Tourism Bungy jumping and Bridge Climb AJ Hackett operates a bungy jump experience and a guided bridge climb over the arch truss. In popular culture, Bryan Bruce's television documentary The Bridge (2002) featured footage of the first bungy jump from the Auckland Harbour Bridge. Vector lights Vector Limited, a utility company in New Zealand, uses LED lights with various colours to illuminate the bridge for ornamental reasons. The lights are powered by renewable energy and the installation was completed in November 2017. == Maintenance and notable issues ==

Long-term maintenance and strengthening: clip-ons The clip-ons have been plagued by significant issues. In 1987, cracks required major repair works, and in 2006, further cracks and signs of material fatigue were found. Auckland City Council's Transport Committee requested Transit New Zealand to investigate the future of the clip-ons as part of its ten-year plan. Transit noted that the plan already includes some funding for bridge maintenance. In May 2007, Transit proposed a by-law change banning vehicles over 4.5 tonnes from the outside lane on each clip-on to reduce stress on the structure. This was changed in July 2007 to a bylaw banning vehicles of 13 tonnes or more, based on the high level of voluntary compliance during the previous months. In 2007, it was announced that NZ$45 million in maintenance work on the clip-ons was brought forward as part of good practice. In October 2007, a 2006 report from Beca Group surfaced in the press, noting that the clip-ons were at risk of catastrophic, immediate failure in circumstances such as a traffic jam trapping a large number of trucks. Transit noted that this situation was extremely unlikely, and measures already implemented would prevent it from occurring. In January 2008, it became known that even after the multimillion-dollar maintenance works, a full ban for trucks on all clip-on lanes might be required, or the working life could be reduced to only ten more years. In late 2009, it was announced that due to greater than expected complexity of the task and increasing material costs for the 920 tons of reinforcing material instead of the approximately half amount of that originally envisaged, clip-on maintenance costs had increased by a further NZ$41 million. Resonance The natural sway motion of people walking on the bridge's clip-on segment during special events such as the Auckland Marathon can lead the bridge to oscillate sideways. It has been reported that the oscillations can inflict "serious crushing injuries". The bridge's movement is caused by synchronous lateral excitation, a positive feedback phenomenon. It has been a known issue since at least 1975, and the lateral frequency is reported to be at 0.67 Hz. Seismic vulnerability and mitigation In 1996, NZTA began a seismic screening programme to identify existing bridges that may sustain damage in an earthquake. Over several years following the assessment, the bridge has completed seismic retrofit. Ship strike risks The Baltimore Key Bridge collapse in March 2024 prompted NZTA to review Auckland Harbour Bridge safety measures. The review classified the risk of vessel collision with the bridge as "rare," citing multiple existing safety measures. The review also stated that Chelsea sugar ship is the only cargo ship that regularly passes under the bridge. Suicides The bridge is associated with suicide attempts. In 2010, a news article reported that one to two individuals die by suicide at the location per year. In 2019, a feasibility study of retrofitting suicide prevention barrier was published. It examined two types of barriers, a vertical anti-climb barrier and horizontal fall prevention barrier. As of 2024, no barriers have been implemented. 2020 structural damage On Friday, 18 September 2020, at approximately 11:00 AM, high winds, with gusts up to , caused a heavy goods vehicle travelling in the central span of the bridge to strike a main diagonal member of the box truss member. The incident reportedly caused severe damage and a significant reduction in daily traffic capacity. Temporary repairs were effected using a locally fabricated replacement member, pending a full engineering analysis and design of the long-term solution. On 4 October, a permanent replacement strut was installed, with all lanes opening again on 7 October 2020. Since the September 2020 incident up until 2024, the bridge has been closed 20 times totalling 435 minutes and costing over $35.6 million in economic damage. == Proposed shared path ==

Original proposal When the bridge was built, rail lines and walking paths were dropped for cost reasons, A 2008 proposal to modify the clip-ons and potentially widen them to add walking and cycling paths met with different reactions. While Auckland Regional Council and North Shore City Council voted to support it (under certain conditions), Auckland City Council considered the costs to be too high. The NZTA considered the proposal as not having enough merit for the $22–53 million cost, though campaigners noted that the costs cited for the project included 45% contingencies. A proposal from the Auckland Regional Council (one of the proponents) to open up part of the clip-on structure for a walking / cycling trial use over several summer weekends, to show whether it would attract enough users, did not go forward. Following years of campaigning, Skypath, was promised funding by the Labour Party in the lead-up to the 2017 general election. Once Labour was in government, the project was passed to NZTA which released a revised design in 2019. In June 2021, Transport Minister Michael Wood announced a new stand-alone walking and cycling bridge would be built on the eastern side of the Auckland Harbour Bridge. The bridge was estimated to cost a total of $785 million and had the support of Auckland mayor Phil Goff. The plan received criticism from cycling, trucking and other transport advocates, as well as from the government opposition parties. In October 2021, Wood announced the project had been scrapped due to lack of public support. He said NZTA had spent $51 million on designs, consultants and engineering plans for the project up until the end of September, and the final amount spent was not known. On 6 August 2023, NZTA announced their Waitematā Harbour Crossings plan which includes a tunnel for light rail and a tunnel for motor traffic under the harbour, and walking and cycling on two lanes of the existing Harbour Bridge. It was forecasted that 6400 people would walk and cycle across the Auckland Harbour Bridge every day. This proposal was abandoned under the new government, stating that the government would not fund any projects to allow cycling across the Harbour Bridge. Protests On Sunday, 24 May 2009, thousands of people crossed the bridge as a part of a protest by GetAcross against the bridge not providing walking and cycling access, and against what the group perceives to be the authorities' negative and obstructionist attitude towards such access. A crossing either as part of the protest or as part of the official 50-year anniversary celebrations had been forbidden by NZTA. Despite this, several people made their way around the police cordon onto the bridge. At that stage police closed the northbound lanes to traffic, bringing State Highway 1 to a stop. to being considered a successful signal to authorities to give more weight to the demands and the public backing of the walk and cycleway proponents. NZTA representatives noted that they were disappointed at what they considered the broken word of the organisers of the protest, and remarked that it would take 30 more years before walking and cycling could likely be provided (see also "Second Harbour Crossing" below). In 2011, the proposal got new public support when Auckland Mayor Len Brown agreed that a walk- and cycleway was a desirable goal, and instructed Auckland Transport to add it to its strategic priorities. The walk- and cycleway is also to be included in the city centre masterplan. Three council-controlled organisations (CCOs) – Auckland Transport, the Waterfront Development Agency and the Tourism, Events and Economic Development Agency – indicated support for the proposal, as has the Heart of the City (Auckland CBD) business association. In 2014, the proposed walk and cycleway was publicly notified, and consent was given in 2015. However, this was appealed by three local groups. The decision of the original hearing was upheld in December 2016, and the last appeal rejected by the Environment Court. In the meantime, Council had already provided in principle approval for a public-private partnership funding model, in a unanimous support vote earlier in 2016. On 30 May 2021, more than 1,500 cyclists crossed the bridge following a rally at Point Erin Park organised by Bike Auckland. The rally was motivated by uncertainty around the future of the SkyPath project. NZTA had stopped supporting the project due to technical issues. The Western clip on of the bridge (two motor traffic lanes) had been closed in advance of the rally, with a police cordon blocking access. After Bike Auckland's rally concluded, much of the crowd made their way over to the police cordon and pushed past onto the bridge. ==Second Harbour Crossing==

Almost as soon as the bridge was built it reached capacity, before extension via the clip-ons, and a second crossing of the harbour was mooted. The high costs and the difficulties of connecting it to the motorway network have so far caused plans to remain at concept stage. In 2008, a study group narrowed down around 160 options to a multi-tunnel link approximately one km east of the bridge, with up to four individual tunnels for motorway, public transport and rail. On 6 August 2023, NZTA announced their Waitematā Harbour Crossings plan which includes a tunnel for light rail and a tunnel for motor traffic, with walking and cycling on two lanes of the existing Harbour Bridge. Construction is expected to start by 2029. Waka Kotahi's forecast is that 6,400 people would walk and cycle across the bridge every day. ==See also==