Holland Tunnel

Each tube has a 29.5-foot (9.0 m) diameter, and the two tubes run 15 feet (4.6 m) apart under the Hudson River. The exteriors of each tube are composed of a series of cast iron rings, each of which comprises 14 curved steel pieces that are each 6 feet (1.8 m) long. The steel rings are covered by a 19-inch-thick (48 cm) layer of concrete.^[3]:3 Each tube provides a 20-foot (6.1 m) roadway with two lanes and 12 feet 6 inches (3.81 m) of vertical clearance. The north tube is 8,558 feet (2,608 m) between portals, while the south tube is slightly shorter, at 8,371 feet (2,551 m).^[3]:3[4] If each tube's immediate approach roads are included, the north tube is 9,210 feet (2,807 m) long and the south tube 9,275 feet (2,827 m) long.^[3]:3 Most vehicles carrying hazmats, trucks with more than three axles, and vehicles towing trailers cannot use the tunnel. There is a width limit of 8 feet (2.4 m) for vehicles entering the tunnel.^[16]

Both tubes' underwater sections are 5,410 feet (1,650 m) long and are situated in the silt beneath the river.^[3]:3 The lowest point of the roadways is about 93 feet (28.3 m) below mean high water. The lowest point of the tunnel ceiling is about 72 feet (21.9 m) below mean high water.^[4][17][18] The tubes descend at a maximum grade of 4.06% and ascend at a grade of up to 3.8%.^[18] The tubes stretch an additional 1,000 feet (300 m) from the eastern shoreline to the New York portals, and 500 feet (150 m) from the western shoreline to the New Jersey portals.^[3]:4 These sections of the tunnel are more rectangular in shape, since they were built as open cuts that were later covered over.^[3]:4 The walls and ceiling are furnished with glazed ceramic tiles, which were originally engineered to minimize staining.^[18] The majority of the tiles are white, but there is a two-tile-high band of yellow-orange tiles at the bottom of each tube's walls, as well as two-tile-high band of blue tiles on the top.^[3]:4[19]

The northern tube, which carries westbound traffic, originates at Broome Street in Lower Manhattan between Varick and Hudson Streets. It continues to 14th Street east of Marin Boulevard in Jersey City. The southern tube, designed for eastbound traffic, originates at 12th Street east of Marin Boulevard, and surfaces at the Holland Tunnel Rotary in Manhattan.^[17] The entrance and exit ramps to and from each portal are lined with granite and are 30 feet (9.1 m) wide.^[3]:5 Although the two tubes' underwater sections are parallel and adjacent to each other, the tubes' portals on either side are located two blocks apart in order to reduce congestion on each side.^[20][3]:4

ホーランドトンネルのチューブは当初、ベルギーブロックとコンクリートでできた路面を備えていました。これは1955年にアスファルトに置き換えられました。^{[ 3 ] : 5}各チューブの左側（内側）には、路面から4フィート（1.2m ）上に持ち上げられたキャットウォークがあります。^{[ 17 ]} 5つの非常口通路が2つのチューブの内側のキャットウォークをつないでいます。^{[ 3 ] : 6}ホーランドトンネルが開通したとき、キャットウォークには250フィート（76m ）間隔で警察ブースと電話システムが設置されていました。^{[ 20 ]}  

2004年8月の脅迫を受けて実施されたニューヨーク市への商用車の進入禁止など、9月11日の攻撃を受けて東行きの交通に厳しい制限が課されたにもかかわらず、ホーランドトンネルを通過する交通量は安定している。 ^{[ 21 ] [ 22 ]} 9月11日の攻撃直後の急激な減少を除けば、ホーランドトンネルを両方向で毎日利用する車両数は、1999年のピーク時の1日103,020台から2016年には89,792台へと着実に減少している。^{[ 2 ]： 218} 2017年現在オランダトンネルの東行き方向は年間14,871,543台の車両が利用した。^{[ 23 ]}

ホランドトンネルは、世界で初めて機械換気された水中車両トンネルでした。トンネルには、チューブに対して横方向、つまり垂直方向に走る換気システムがあります。 ^{[ 18 ] [ 24 ] [ 25 ]}ハドソン川の両岸には、それぞれ2つの換気シャフト建物があります。1つは陸上にあり、もう1つは川の中にあり、それぞれの岸辺から約1,000フィート（300メートル）離れています。すべての換気建物は、鉄骨と鉄筋コンクリートのフレームを備えたバフ色のレンガのファサードを持っています。^{[ 3 ] : 5 [ 26 ] [ 6 ]} 

川の中にある竪穴は、平均満潮位から107フィート（33メートル）の高さまで伸びています。それを支える橋脚は45フィート（14メートル）下まで伸びており、そのうち40フィート（12メートル）は水面下、5フィート（1.5メートル）は川底に埋め込まれています。^{[ 3 ]： 5 [ 24 ]}川の竪穴は、各換気竪穴を海岸線に接続する船舶用桟橋を介して、非常口としても機能します。^{[ 3 ]： 6}ニューヨーク陸上換気塔は、台形の平面形状を持つ5階建ての建物で、高さは122フィート（37メートル）です。ニュージャージー陸上換気塔は、長方形の外周を持つ4階建て、高さ84フィート（26メートル）の建物です。^{[ 3 ]： 5}      

4 基の換気塔には合計 84 基のファンが設置されています。そのうち 42 基は吸気ファンで、毎分84,000 ～ 218,000 立方フィート (2,400 ～ 6,200 m ³ )の容量があります。残りの 42 基は排気ファンで、毎分87,500 ～ 227,000 立方フィート (2,480 ～ 6,430 m ³ )の風を送ることができます。 ^{[ 6 ] [ 17 ]}排気ダクトは換気塔の角にあり、給気ダクトは中央部分にあります。排気ファンを収容する区画は排気スタックの下の角付近に配置され、ファン床の中央部分は吸気ファン用に空いており、各外壁の中央部分は空気取り入れ口になっています。^{[ 27 ]}トンネル建設当時、84 台のファンのうち 3 分の 2 が定期的に使用されており、残りのファンは緊急用に確保されていた。^{[ 28 ]}ファンは新鮮な空気をダクトに送り込み、ダクトはチューブの縁石側の開口部からトンネルに空気を取り込む。天井には空気を排出するためのスリットがある。^{[ 3 ] : 5 [ 24 ] [ 25 ]}ファンは 90 秒ごとにトンネル内の空気をすべて入れ替えることができる。自動車の排気ガスに含まれる有毒な一酸化炭素成分のため、強制換気システムが不可欠である。一酸化炭素は触媒コンバーターが普及する前は排気ガスのかなり大きな割合を占めていた。^{[ 3 ] : 6 [ 29 ] [ 30 ]}  

The approach to the Holland Tunnel in Jersey City begins where the lower level of NJ Route 139 and the Newark Bay Extension merge. On May 6, 1936, the section of what became Route 139/I-78 between Jersey Avenue and Marin Boulevard was named in memory of John F. Boyle, the former interstate tunnel commissioner.^[31] Despite being part of the Interstate Highway System, I-78 and Route 139 run concurrently along 12th and 14th Streets to reach the Holland Tunnel. Westbound traffic uses 14th Street while eastbound traffic uses 12th Street. The plaza was restored and landscaped by the Jersey City government in 1982.^[32]

There is a nine-lane toll plaza for eastbound traffic only at the eastern end of 12th Street, just west of the tunnel portal.^[4] The original toll plaza had eight lanes;^[20] it was renovated in 1953–1954,^[33][3]:6 and the current nine-lane tollbooth was constructed in 1988.^[34][3]:6

The Jersey City entrance during rush hour in May 2010

Soon after construction of the tunnel, and amid rising vehicular traffic in the area, a railroad freight depot, St. John's Park Terminal, was abandoned and later demolished. The depot was located on the city block bounded by Laight, Varick, Beach, and Hudson Streets.^[35] The depot's site was used as a storage yard until the 1960s when it became a circular roadway for traffic exiting the eastbound tube in Manhattan.^[36][37]

The plaza originally had four exits. It was renovated in the early 2000s with landscaping by Studio V Architecture^[38] and Ives Architecture Studio.^[39] A fifth exit was added in 2004.^[40][41]

Originally used as the toll plazas for New Jersey-bound traffic, the small triangular patches of land at the mouth of the westbound tube entrance are referred to as Freeman Plaza or Freeman Square. The plaza is named after Milton Freeman, the engineer who took over the Holland Tunnel project after the death of Clifford Milburn Holland.^[42] The Freeman Plaza received its name just before the tunnel opened in 1927. The toll plaza was removed circa 1971 when the Port Authority stopped collecting tolls for New Jersey-bound drivers, and the square was later fenced off by the Port Authority.^[3]:7[43] The small maintenance buildings for toll collectors were removed around 1982 or 1983.^[3]:7 A bust of Holland sits outside the entrance to the westbound tube in Freeman Plaza.^[44]:16

A business improvement district for the area, the Hudson Square Connection, was founded in 2009 with the goal of repurposing the square for pedestrian use.^[43][45] Hudson Square Connection and the Port Authority collaborated to create a five-year, $27 million master plan for Freeman Plaza.^[46] In 2013, Freeman Plaza West was opened to the public. Bounded by Hudson, Broome, and Watts Streets, it features umbrellas, bistro tables and chairs, and tree plantings.^[47]

In 2014, Freeman Plaza East and Freeman Plaza North were opened on Varick and Broome Streets, respectively. The plazas contained chaise longues, bistro tables, and umbrellas.^[48] In 2016, the Hudson Square Connection added solar powered charging stations to both plazas, and introduced a summer lunchtime music series, called live@lunch.^[49] A statue by the artist Isamu Noguchi was also installed within the plaza.^[50] To the south of Freeman Plaza, between Varick, Watts, and Canal Streets is One Hudson Square, a New York City designated landmark in 2013.^[51]

In 1906, the New York and New Jersey Interstate Bridge Commission, a consortium of three groups, was formed to consider the need for a crossing across the Hudson River between New York City and New Jersey.^[57] That year, three railroads asked the commission to consider building a railroad bridge over the river.^[58] In 1908, the commission considered building three bridges across the Hudson River at 57th, 110th, and 179th Streets in Manhattan. The reasoning was that bridges would be cheaper than tunnels.^[59] These three locations were considered to be the only suitable locations for suspension bridges; other sites were rejected on the grounds of aesthetics, geography, or traffic flows.^[57][60] John Vipond Davies, one of the partners for the consulting firm Jacobs and Davies (which had constructed the Uptown Hudson Tubes), wanted to build a vehicular tunnel between Canal Street, Manhattan, and 13th Street, Jersey City. This proposal would compete with the six-lane suspension bridge at 57th Street.^[61] Some plans provided for the construction of both the bridge and the tunnel.^[61][62] The ferries could not accommodate all of the 19,600 vehicles per day, as of 1913, that traveled between New York and New Jersey.^[62] The Bridge Commission hosted several meetings to tell truck drivers about the details of both the 57th Street Bridge and Canal Street Tunnel plans.^[63]

The United States Department of War brought up concerns about the 57th Street bridge plans: the span would need to be at least 200 feet (61 m) above the mean high water to avoid interfering with shipping.^[44]:13 By comparison, the tunnel would be 95 feet (29 m) below mean water level.^[62] The Interstate Bridge Commission, which had been renamed the New York State Bridge and Tunnel Commission in April 1913,^[64][65] published a report that same month, stating that the Canal Street tunnel would cost $11 million while the 57th Street bridge would cost $42 million.^[60] In October 1913, Jacobs and Davies stated that a pair of tunnels, with each tube carrying traffic in one direction, would cost only $11 million, while a bridge might cost over $50 million. The low elevation and deep bedrock of Lower Manhattan was more conducive to a tunnel than to a bridge.^{[44]:13–14[66][67]} By the end of that year, the consulting engineers for both the 57th Street Bridge and the Canal Street Tunnel had submitted their plans to the Bridge and Tunnel Commission.^[68] New York City merchants mainly advocated for the tunnel plan, while New Jerseyans and New York automobile drivers mostly supported the bridge plan.^[69] Meanwhile, the New York State Bridge and Tunnel Commission indicated that it favored the Canal Street tunnel plan. On the other hand, the 57th Street bridge plan remained largely forgotten.^[67][68]

The Public Service Commission of New Jersey published a report in April 1917, stating that the construction of a Hudson River vehicle tunnel from Lower Manhattan to Jersey City was feasible.^[70] That June, following this report, Walter E. Edge, then Governor of New Jersey, convened the Hudson River Bridge and Tunnel Commission of New Jersey, which would work with the New York Bridge and Tunnel Commission to construct the new tunnel.^[44]:15[71] In March 1918, a report was sent to the New York State Legislature, advocating for the construction of the tunnel as soon as possible.^[72] That year, six million dollars in funding for the Hudson River Tunnel was proposed in two bills presented to subcommittees of the United States Senate and House of Representatives.^[73][72] The bill was voted down by the Interstate Commerce Committee before it could be presented to the full Senate.^[74]

The original plans for the Hudson River tunnel were for twin two-lane tubes, with each tube carrying traffic in a single direction.^[57] A request for proposals for the tunnel was announced in 1918, and eleven such requests were considered.^[44]:15[75] One of these proposals, authored by engineer George Goethals, was for a bi-level tube.^[57][76] A modification of Jacobs and Davies' 1913 plan,^[72] the Goethals proposal specified that each level would carry three lanes of traffic, and that traffic on each level would run in a different direction.^[44]:15[76] Goethals stated that his plan would cost $12 million and could be completed in three years.^[77] Subsequently, John F. O'Rourke offered to build the tunnel for $11.5 million.^[78] Goethals cited the area's freight traffic as one of the reasons for constructing the tube.^[72] His proposal would use a 42-foot (13 m) diameter shield to dig the tunnel.^[57][78][79] This large tunnel size was seen as a potential problem, since there were differences in the air pressure at the top and the bottom of each tunnel, and that air pressure difference increased with a larger tunnel diameter. Five engineers were assigned to examine the feasibility of Goethals's design.^[79] In July 1919, President Woodrow Wilson ratified a Congressional joint resolution for a trans-Hudson tunnel,^[3]:9 and Clifford Milburn Holland was named the project's chief engineer.^[6] Holland stated that, based on the construction methods used for both pair of tubes, including the downtown pair, it should be relatively easy to dig through the mud on the bottom of the Hudson River, and that construction should be completed within two years.^[80]

連邦政府は、たとえ一部であってもこのプロジェクトへの資金提供を拒否したため、資金調達は各州に委ねられた。^{[ 57 ]} 1919年6月、米国上院議員で元ニュージャージー州知事のエッジは、ハドソン川トンネル法案の別のバージョンを米国上院に提出し、承認された。^{[ 81 ]}ニューヨーク州とニュージャージー州の政府は、1919年9月に契約を締結し、両州は共同でトンネルを建設、運営、維持することに合意した。^{[ 44 ] : 16 [ 82 ]}この契約は、1920年1月に各州のトンネル委員会によって署名された。^{[ 83 ]}

ホランドの計画では、2本のチューブはそれぞれ外径が外張りを含めて29フィート（8.8メートル）で、チューブ内には合計幅20フィート（6.1メートル）の2車線道路が設けられる予定だった。^{[ 75 ] [ 84 ]} 1車線は低速交通用、もう1車線は高速交通用となる。これは、3本の道路の合計幅が24.5フィート（7.5メートル）で、ホランドの2車線道路よりわずか数フィート広いだけのゲータルズの計画とは対照的だった。 ^{[ 85 ]}さらに、ホランドによれば、幅42フィートのチューブは、29フィートのチューブ2本を合わせたよりも多くの土砂を掘削する必要がある。直径29フィートの円2つを合わせた面積は5,282.2平方フィート（490.73^平方メートル）であるのに対し、直径42フィートの円は5,541.8平方フィート（514.85平方メートル^）となる。^{[ 44 ] : 17 [ 57 ] [ 85 ]}より北にある西行きのチューブは、マンハッタン側のブルーム通りとヴァリック通りから始まり、ニュージャージー側の14番街とプロボスト通りの現在取り壊された交差点で終わる。南寄りの東行きトンネルは、ジャージーシティの12番街とプロボスト通りの交差点（現在もそのまま残っている）から始まり、ヴァリック通り近くのキャナル通りの南側で終わる予定だった。^{[ 75 ]}比較のために言うと、ゴエサルズの計画では、両側の入口と出口の広場を一体化することになっていた。^{[ 44 ] : 18}アメリカ自動車トラック協会は、各トンネルに3車線を設けるよう提唱したが、実現しなかった。^{[ 86 ]}     

Even though Goethals's method of digging had not been tested, he refused to concede to Holland's proposal, and demanded to see evidence that Holland's proposal would work.^[44]:18 The New York and New Jersey Tunnel Commission subsequently rejected Goethals's plan in favor of a twin-tube proposal that Holland had devised, which was valued at around $28.7 million.^[75][84] When Goethals asked why, the commission responded that Goethals's proposal had never been tested; that it was too expensive; and that the tunnel plans had many engineering weaknesses that could cause the tube to flood.^[87] Additionally, while a tube with three lanes in each direction would be able to handle more traffic than a tube with two lanes, projections showed that traffic on the tunnel's approach roads could barely handle the amount of traffic going to and from the two-lane tubes, and that widening the approach roads on each side would cost millions of dollars more.^[85] The commission then voted to forbid any further consideration of Goethals's plan.^[88] Holland defended his own plan by pointing out that the roadways in Goethals's plan would not only feature narrower road lanes, but also would have ventilation ducts that were too small to ventilate the tube efficiently.^[89]

In May 1920, the New Jersey Legislature voted to approve the start of construction, overriding a veto from the New Jersey governor.^[90] The same month, the New York governor signed a similar bill that had been passed in the New York legislature.^[91] The legislature of New Jersey approved a $5 million bond issue for the tunnel in December 1920.^[92]

1985年に撮影されたニューヨーク土地換気ビルの塔の写真。このような塔は4基あるうちの1基。

ニュージャージー州ジャージーシティにあるハドソン川の換気塔

ホーランドトンネルの最も重要な設計上の特徴は換気システムであり、ノルウェーの建築家アーリング・オウレが設計した4つの換気塔によって換気が行われています。^{[ 98 ]} 建設当時、水中トンネルは土木工学の確立された一部でしたが、ニューヨーク市の水路の下にある既存のトンネルはすべて鉄道と地下鉄のみを通していたため、長い車両用トンネルは建設されていませんでした。これらのトンネルは、トンネルを使用する列車が電気で動く必要があり、そのため汚染物質の排出量が非常に少なかったため、換気の必要性はそれほど高くありませんでした。^{[ 3 ] : 10 [ 95 ]}一方、ホーランドトンネルの交通は主にガソリン車で構成されており、一酸化炭素の排出物を排出するために換気が必要でした。そうしないと、運転手が窒息してしまうからです。^{[ 3 ] : 10 [ 99 ] : 181–202 [ 100 ]}当時、鉄道交通に使用されていないトンネルはごくわずかでした。これらの非鉄道トンネルの中で最も有名なのは、ロンドンのブラックウォールトンネルとロザーハイズトンネルで、機械換気は必要ありませんでした。^{[ 3 ] : 10}しかし、ハドソン川トンネルのような長さのトンネルには効率的な換気方法が必要だったため、主任技師シングスタッドはトンネルを横方向に（チューブに垂直に）換気するシステムを先駆的に開発しました。^{[ 8 ] [ 101 ]}

In October 1920, General George R. Dyer, the chairman of the New York Tunnel Commission, published a report in which he wrote that Singstad had devised a feasible ventilation system for the Hudson River Tunnel.^[95] Working with Yale University, the University of Illinois, and the United States Bureau of Mines, Singstad built a test tunnel in the bureau's experimental mine at Bruceton, Pennsylvania, measuring over 400 feet (122 m) long, where cars were lined up with engines running. Volunteer students were supervised as they breathed the exhaust in order to confirm air flows and tolerable carbon monoxide levels by simulating different traffic conditions, including backups.^[25][101] The University of Illinois, which had hired the only professors of ventilation in the United States, built an experimental 300-foot-long (91 m) ventilation duct at its Urbana campus to test air flows.^[101][102] In October 1921, Singstad concluded that a conventional, longitudinal ventilation system would have to be pressurized to an air flow rate of 27 cubic meters per second (953 cu ft/s) along the tunnel.^[25] On the other hand, the tunnel could be adequately ventilated transversely if the compartment carrying the tube's roadway was placed in between two plenums. A lower plenum below the roadway floor could supply fresh air, and an upper plenum above the ceiling could exhaust fumes at regular intervals.^[25][24]

Two thousand tests were performed with the ventilation system prototype.^[6] The system was determined to be of sufficiently low cost, relative to the safety benefits, that it was ultimately integrated into the tunnel's design.^[101] By the time the tunnel was in service, the average carbon monoxide content in both tunnels was 0.69 parts per 10,000 parts of air. The highest recorded carbon monoxide level in the Holland Tunnel was 1.60 parts per 10,000, well below the permissible maximum of 4 parts per 10,000.^[18][99] The public and the press proclaimed air conditions were better in the tubes than in some streets of New York City; after the tunnel opened, Singstad stated that the carbon monoxide content in the tubes were half of those recorded on the streets.^[99][103]

換気システムやその他の潜在的な問題は 1921 年 12 月までに解決され、当局は翌春にトンネルの起工式を行うと発表した。^{[ 104 ]}当初、建設業者はハドソン川の底に溝を掘ってから埋めることを検討したが、川底を構成する軟弱な土壌と、川を利用する船舶交通量が多いことから、これは実現不可能と判断された。^{[ 3 ] : 11}当局はトンネルの進入路にある土地の買収を開始し、テナントを「遅滞なく」立ち退かせて補償を行い、建設を速やかに開始できるようにした。^{[ 105 ]}トンネル建設の入札が公示され、3 社が応札した。^{[ 106 ]} 1922 年 3 月 29 日、トンネル掘削の契約は最低入札者である Booth & Flinn Ltd. に 1,930 万ドルで落札された 。^{[ 107 ]}ハドソン川トンネルに必要な資材はすでに購入済みだったので、すぐに工事を開始することが決定された。^{[ 108 ]} 2日後、作業員がチューブを駆動するための空気圧縮機の設置場所を掘り起こし、掘削工事が始まった。空気圧縮機の設置式は、マンハッタン側のキャナルストリートとウエストサイドハイウェイの交差点で行われた。^{[ 109 ]} 「サンドホッグ」と呼ばれた掘削作業員は、ハドソン川の両岸からチューブを1組ずつ掘り、最終的に川底の下のどこかで両側が接続されるようにすることになっていた。トンネルは入口間が9,250フィート（2,820メートル）で、道路は平均満潮位から最大93フィート（28メートル）下まで下がっていた。 ^{[ 108 ]}  

ニュージャージー側からのトンネル建設の開始は、ハドソン川車両トンネル委員会がプロジェクト用地の一部をまだ取得していなかったため遅れた。^{[ 110 ]}ジャージーシティの当局者はトンネル委員会にジャージーシティの12番街と14番街を拡幅するよう主張していたが、^{[ 111 ]}これらの当局者は、道路拡幅のために取得される予定の土地の一部を所有していたエリー鉄道と売却価格をめぐって意見の相違があった。その結果、ハドソン川トンネルの工事は1年遅れ、早くても1926年までに完了することはできなかった。^{[ 110 ]}ニュージャージー側の工事は、ジャージーシティの当局者がトンネル広場の建設のために公有地を譲渡することを引き続き拒否した後、1922年5月30日にようやく開始された。ジャージーシティ商工会議所は、ニュージャージー州トンネル委員会のハドソン川トンネル委員会の委員が、翌日の新聞で起工式について知るまで通知を受けていなかったため、この行動を非難する書簡を送った。^{[ 112 ]} 6月中旬、州の裁判官は、ジャージーシティの当局者がハドソン川トンネルの建設を妨害しようとすることを禁じる差し止め命令を恒久的なものとした。^{[ 113 ]}ハドソン川トンネル委員会は最終的に、ジャージーシティがトンネル建設を阻止するために様々な努力をしたため、同市は独自の起工式を行わないことを決定した。^{[ 114 ]}しかし、ジャージーシティの当局者は主に建設を遅らせたとして非難されていたが、両州の当局者は、建設プロセスの一環として、トンネル委員会にハドソン川トンネルへの進入路を拡幅することを求めていた。^{[ 115 ]}

このプロジェクトでは、トンネル掘削シールドが6台納入される予定だった。^{[ 108 ]}これらのシールドは、トンネルの穴よりも直径の大きい円筒で構成されており、これらの円筒には、川底の下に打ち込まれる面にさまざまな厚さの鋼板が取り付けられていた。^{[ 26 ]}シールドのうち4台はハドソン川トンネルを川の下に掘り、残りの2台はハドソン川西岸からジャージーシティの坑口まで掘り進む予定だった。岩盤を1日あたり2.5フィート（0.76メートル） 、泥を1日あたり5～6フィート（1.5～1.8メートル）の速度で掘り進むことができた。空気圧縮機は、1平方インチあたり20～45ポンド（140～310キロパスカル）の空気圧を供給する予定だった。^{[ 116 ]}トンネル掘削に使用されたショベルはマリオン・パワー・ショベル社が提供し、^{[ 117 ]} 6 台の掘削シールドはマーチャンツ造船会社が製造した。^{[ 118 ]}空気圧縮機は 1922 年 9 月に完成し、最初のシールドがマンハッタン側の建設立坑に設置された。この時点で、ニュージャージー側の立坑の掘削が行われ、2 基の防水ケーソンが建設されていた。^{[ 119 ] [ 26 ]}   

シールド掘削は、シールドの作業に必要な鋼板が納入された後、その年の 10 月下旬に開始された。^{[ 120 ]}チューブの内側を覆う最初の恒久的な鋼製リングは、その直後に設置された。^{[ 121 ]}ケーソンは 12 月に完成し、川に進水した。^{[ 122 ]}ケーソンにエアロックなどの必要な設備が取り付けられた後、^{[ 26 ]}タグボートが 1923 年 1 月にケーソンを所定の位置に降ろした。^{[ 123 ]}関係者は、このペースで進めば、トンネルは 36 か月以内に、つまり 1926 年末か 1927 年初めまでに完成すると予測した。^{[ 124 ]}

Tunnel construction required the sandhogs to spend large amounts of time in the caisson under high pressure of up to 47.5 pounds per square inch (328 kPa), which was thought to be necessary to prevent river water from entering prior to completion of the tubes.^[125] The caissons were massive metal boxes with varying dimensions, but each contained 6-foot-thick (1.8 m) walls.^[26] Sandhogs entered the tunnel through a series of airlocks, and could only remain inside of the tunnel for a designated time period. On exiting the tunnel, sandhogs had to undergo controlled decompression to avoid decompression sickness or "the bends", a condition in which nitrogen bubbles form in the blood from rapid decompression.^[125][126] The rate of decompression for sandhogs working on the Hudson River Tunnel was described as being "so small as to be negligible".^[127] Sandhogs underwent such decompressions 756,000 times throughout the course of construction, which resulted in 528 cases of the bends, though none were fatal.^[128] The tunnel's pressurization caused other problems, including a pressure blowout in April 1924 that flooded the tube.^[129][126]

Due to the geology of the Hudson River, the shields digging from the New Jersey side were mostly being driven through mud, and so could be driven at a faster rate than the shields from the New York side, which were being dug through large rock formations. When workers tried to dig through the Manhattan shoreline, they had encountered several weeks of delay due to the existence of an as-yet-unrecorded granite bulkhead on the shoreline.^[130] In September 1923, after having proceeded about 1,100 feet (340 m) from the Manhattan shoreline, workers encountered a sheet of Manhattan schist under the riverbed, forcing them to slow shield digging operations from 12.5 feet per day (3.8 m/d) to less than 1 foot per day (0.30 m/d). This outcropping was fed from a stream in Manhattan that emptied into the Hudson River. The sandhogs planned to use small explosive charges to dig through the rock shelf without damaging the shield.^[131] By December 1923, about 4,400 feet (1,300 m) of each tube's total length had been excavated, and the first of the shields had passed through the underwater shafts that had been sunk during construction.^[130] Due to these unexpected issues, the cost estimate for the tunnel was increased from $28 million to $42 million in January 1924.^[132] By March 1924, all seven of the ventilation shafts had been dug, and three of the four shields that were digging underwater had passed through their respective underwater construction shafts, with the fourth shield nearing its respective shaft.^[127]

Workers also performed tests to determine whether they could receive radio transmissions while inside the tunnel. They found that they were able to receive transmissions within much of the Hudson River Tunnel.^[133] However, a New Jersey radio station later found that there was a spot in the middle of the tunnel that had no reception.^[134]

The cost of the project increased as work progressed. In July 1923, the New York and New Jersey Vehicular Tunnel Commission had revised plans for the entrance and exit plazas on each side to accommodate an increase in traffic along Canal Street on the Manhattan side. The commission had spent $2.1 million to acquire land.^[135] Further redesigns were made in January 1924 due to a change of major components in the tunnel plan, including tunnel diameters and ventilation systems, which had increased the cost by another $14 million.^[135]

The two ends of both tubes were scheduled to be connected to each other at a ceremony on October 29, 1924, in which President Calvin Coolidge would have remotely set off an explosion to connect the tunnel's two sides.^[136] However, two days before the ceremony, Holland died of a heart attack at the sanatorium in Battle Creek, Michigan, aged 41. Individuals cited in The New York Times attributed his death to the stress associated with overseeing the tunnel's construction. The ceremony was postponed out of respect for Holland's death.^[137]

The tunnel was ultimately holed through on October 29, but it was a nondescript event without any ceremony.^[9] On November 12, 1924, the Hudson River Vehicular Tunnel was renamed the Holland Tunnel by the two states' respective tunnel commissions.^[138] Holland was succeeded by Milton Harvey Freeman, who died of pneumonia in March 1925, after several months of overseeing the project.^[6][7] After Freeman's death, the position was occupied by Ole Singstad, who oversaw the tunnel's completion.^[8][6]

As part of the tunnel project, one block of Watts Street in Manhattan was widened to accommodate traffic heading toward the westbound tube.^[139]Sixth Avenue was also widened and extended between Greenwich Village and Church Street. Ten thousand people were evicted to make way for the Sixth Avenue extension.^[140] The north–south Church Street was widened and extended southward to Church Street and Trinity Place; West Side Highway was expanded and supplemented with an elevated highway; and the west-east Vestry and Laight Streets were also widened.^[141] On the New Jersey side, the Holland Tunnel was to connect a new highway (formerly the Route 1 Extension; now New Jersey Route 139), which extended westward to Newark.^[17] This included a 2,100-foot (640 m) viaduct, rising 80 feet (24 m) from 12th and 14th Streets, at the bottom of the Palisades, to the new highway, at the top of the Palisades.^[141] The New Jersey highway approach was opened in stages beginning in 1927,^[142] and most of that highway was finished in 1930.^[143]

The construction of the tunnel approach roads on the New Jersey side was delayed for months by Erie Railroad, whose Bergen Arches right-of-way ran parallel to and directly south of Route 139, in the right of way of the proposed approach roads. Although the Erie had promised to find another site for its railroad yards, it had refused to respond to the plans that the New Jersey State Highway Commission had sent them. In March 1925, the Highway Commission decided that construction on the approach roads would begin regardless of Erie's response, and so the land would be taken using eminent domain.^[144] This led to a legal disagreement between the Erie and the Highway Commission.^[145] The Erie maintained that it absolutely needed 30 feet of land along 12th Street, while the Highway Commission stated that the most direct approach to the eastbound Holland Tunnel's 12th Street portal should be made using 12th Street. The commission rejected a suggestion that it should use 13th Street, one block north, because it would cost $500,000 more and involve two perpendicular turns.^[146] In October 1926, one million dollars was allocated to the completion of the Route 139 approach.^[147]

The contracts for constructing the Holland Tunnel's ventilation systems were awarded in December 1925.^[148] Two months later, the New York-New Jersey Vehicular Tunnel Commission asked for $3.2 million more in funding. The tunnel was now expected to cost $46 million, an increase of $17 million over what was originally budgeted.^[135] The Holland Tunnel was nearly complete: in March 1926, Singstad stated that the tunnel was expected to be opened by the following February.^[149] By May 1926, the tubes had been almost completely furnished: the polished-white tile walls were in place, as were the bright lighting systems and the Belgian-block-and-concrete road surfaces.^[17] The north tube's tiles were sourced locally by the Sonzogni Brothers of Union City, New Jersey, while the south tube's tiles were sourced in equal amounts from Czechoslovakia and Germany.^[3]:4 The tiles' surfaces were specially engineered so that they could maintain their coloring even after years of use. The lighting systems used in the Holland Tunnel were designed to allow motorists to adjust to a gradual change in lighting levels just before leaving the tubes.^[18]

The ventilation towers were the only major component of the Holland Tunnel that was not completed, but major progress had been made by the end of 1926.^[24] Ole Singstad and the two states' tunnel commissions tested the tunnel's ventilation system by releasing gas clouds in one of the tubes in February 1927. Singstad subsequently declared that the ventilation system was well equipped to ventilate the tunnel air.^[28] However, the New York Board of Trade and Transportation disagreed, stating that the system would be inadequate if there was a genuine incident within the tunnel. In April 1927, the board had conducted their own tests with two lighted candles, and a cloud of smoke had filled the entire tube before the ventilation system was able to perform a full exhaust.^[150] The Chief Surgeon of the U.S. Board of Mines supported Singstad's position that the ventilation system could sufficiently filter the tubes' air.^[151] To affirm the ventilation system's efficacy, in November 1927, the New York and New Jersey tunnel commissions burned a car within the tunnel; the ventilation system dissipated the fire within three and a half minutes.^[152]

The governors of New York and New Jersey took ceremonial rides through the tunnel in August 1926, meeting at the tunnel's midpoint.^[153] The first unofficial drive through the entirety of the Holland Tunnel was undertaken by a group of British businessmen a year later, in August 1927.^[154] The next month, a group from the Buffalo and Niagara Frontier Port Authority Survey Commission also visited the tunnel.^[155] In October, a delegation of representatives from Detroit, Michigan, and Windsor, Ontario, toured the nearly complete Holland Tunnel to get ideas for the then-proposed Detroit–Windsor Tunnel.^[156][157] A reporter for The New York Times was able to make a test drive through the tunnel, noting that "there is no sudden pressure of wind upon the ear-drums" and that it would reduce the duration of crossing the Hudson River by between 15 and 22 minutes.^[20] Three hundred police officers were trained in advance of the Holland Tunnel's opening,^[158] and bus companies started receiving franchises to operate buses through the tunnel.^[159]

Following the September 11 attacks on the World Trade Center, the Holland Tunnel remained closed to non-emergency traffic for over a month, due to the Manhattan portals' proximity to the World Trade Center site. The westbound lanes of the tunnel reopened on September 28, 2001, though eastbound travel was still restricted only to emergency vehicles.^[225] When the tunnel fully reopened on October 15, strict new regulations were enacted, and single-occupancy vehicles and trucks were banned from entering the tunnel.^[226] In March 2002, before all of the post-9/11 restrictions were lifted, a warehouse fire near the eastbound tube's New Jersey portal caused the tunnel to be closed entirely for five days;^[227] the fire continued for over a week.^[228] That April, all trucks were banned from the westbound tube, and trucks with more than three axles were also banned from the eastbound tube.^[229] Single-occupant vehicles were prohibited in the tunnel on weekday mornings between 6:00 am and 10:00 am until November 17, 2003, when the restrictions were lifted.^[230]