Road Tunnels in the United States: Full List by Length, Opening Dates

• 56entries listed
• 4.18 kmlongest bore
• 1904–2016openings span
• 85.51 kmtotal length

The road tunnels in the united states, ranked by length

How this archive measures: lengths, bores, dates and ordering

Measuring length, and why sources disagree

The table below lists 56 entries with a recorded length, each giving a name, a length in metres and, where documented, the year of opening. The middle half of the table runs from 1.12 km to 2.21 km, and that band is where most of the engineering on this page actually sits.

The shortest recorded entry is 1.01 km against 4.18 km at the top, a spread of 4.16x across the same table. The three longest entries alone account for 9.96 km of the 85.51 km on this page, which is 12 per cent of the total from 3 of 50 rows.

Opening dates are given for admission of traffic, not for breakthrough. 6 of those 56 are recorded as under construction or planned, the longest of them measuring 1.36 km, so the count includes them while every measured figure — the range, the median, the total — describes the 50 rows carrying traffic today: an unopened bore cannot hold a record.

This page records the road tunnels catalogued for the United States in a tunnel almanac maintained at this address since the late 1990s. Lengths for the United States are recorded in metres which is how the operators publish them and why the shortest entry here reads as 1 005 m and not a rounded figure.

25 entries sit above the median and 25 at or below it, so the table is evenly weighted and not clustered at one end. Where one of these 50 lengths disagrees with an operator's own figure for the United States, the table keeps the published value and notes the difference instead of averaging the two.

Why the list is complete rather than a top ten

A new scheme in the United States would have to beat 4.18 km to change the head of this table, and that is the figure worth rechecking when one opens. Dates for the United States refer to opening to traffic, not breakthrough, so the 1904 entry was under construction for some years before that.

Between the longest and the tenth-longest the drop is 1.85 km, which is the part of the table that changes when a single scheme opens. The 50 rows for the United States are ordered by length, not by date, so the 2016 opening sits well down the table without being any less current.

The entries sum to roughly 85.51 km of bore, an average of about 1.71 km each, though that average describes no actual row. The longest entry is 4.2 times the shortest and 2.7 times the median, which is the quickest measure of how uneven the table is.

20 of the 50 entries fall within a quarter of the median length, which is how tightly this particular list clusters around its typical structure. 3 of the dated entries opened from 2010 onwards, which shows how much of what is listed here is recent construction and not historic work.

Opening dates and what they refer to

The shorter half of the table totals 29.9 km against 55.61 km for the longer half, from the same number of rows. Eighth on the list is Thomas O'Neill Jr at 2.4 km, which is where the table stops being about record holders and starts being about ordinary infrastructure.

After the 1940s the next busiest decade here is the 1990s with 6 openings, so the building effort came in more than one wave. The dated entries fall across 33 different years, which is a rough measure of whether this was a sustained programme or a handful of separate schemes.

Reading a list of road tunnels in the united states

Roughly 5 of the dated entries opened in this century, which is a rough measure of how much of the network is recent. The ten longest average 2.76 km against 1.45 km for everything below them, and that ratio is the clearest thing this table says about the distribution.

Where a figure could not be sourced the cell is left blank, so what is shown is measured and nothing is inferred. Laid end to end the entries on this page would run 85.51 km, which is a number with no engineering meaning but a useful sense of the scale of what is catalogued.

Dated entries run from 1904 to 2016, and the busiest decade is the 1940s with 12 recorded openings. The table on this page runs to 56 rows and records State, Tunnel, Length (m), Date of opening and State for each of them, which is the shape the original compiler chose rather than one imposed here.

Length is recorded in metres for every entry, and length alone decides the sort order. 52 of the 56 rows carry an entry in the comment column — 93 per cent of the table — and that column is where the qualifications live: tube counts, closures, boundaries and the reason a figure reads the way it does.

Anyone comparing these figures across borders should read the note column too, since national practice varies. Read down the length (m) column, the 56 values run from 1 005 m to 4 184 m with a midpoint at 1 452 m; the spread rather than the maximum is what says how uneven this set is.

The longest stands 1.18 km clear of the next longest, which is the margin to watch when a new scheme is announced. The captions name 14 distinct places and structures — River, Boston and Penns among them — and those names are the index into the length tables where each is recorded with its own figure.

The dated entries carry 33 distinct opening years across 112 years, and the median opening year is 1957. The material on this page is held in 26 captions rather than in running text, 233 words of it, each written against the image or row it belongs to by the compiler who put the page together.

The tunnel column names 56 distinct entries on this page, Whittier (Anton Anderson Memorial) and Brooklyn Battery among them, each traceable to the operator or administration record it was taken from. Span rather than total length is what places a bridge in a record, because the span is the engineering and the approaches are not.

Where two sources disagree on a length, the operator's own published length is preferred. A tunnel list for the United States reads differently from a neighbouring country's: 2 of these 50 structures pass three kilometres, and the same journey time is bought with one long bore in one country and a dozen short ones in another.

This page is the full reference table, not a top ten, and it carries every entry that meets the inclusion rule. Readers who want road tunnels in the united states by length and not a curated shortlist will find exactly that here. The list is complete, not a top ten, so the tail is visible too.

Sorting on that one dimension is imperfect, since geology decides difficulty, but it is the measure published consistently enough to rank on. Treat the table as the argument and the prose as the footnote: the numbers carry the case. A list assembled this way is easier to audit, because every row names its structure.

Opening dates before 1900 are shown as published, since sources frequently disagree. Nothing in this table is estimated: where a value could not be sourced it is left blank. Comparing one national list against a neighbouring one is more informative than reading either alone, since terrain and funding practice differ sharply across borders.

The longest entry is Whittier, at 4.18 km, opened in 2000. Second and third place go to Brooklyn Battery at 2.78 km and Eisenhower Memorial at 2.73 km. The 1940s account for 12 openings here and the 1990s for 6, so the building effort was not spread evenly across the period.

Further down the table, Ted Williams is recorded at 2.58 km and Lincoln Center at 2.5 km. Openings average one every 2.3 years across the dated entries here, though they arrive in clusters, not at that rate. Administrative boundaries have been redrawn in several countries since these lists were first assembled.