The Oldest Road and Rail Tunnels Still in Use

• 60entries listed
• 19.8 kmlongest bore
• 1802–1907openings span
• 188.09 kmtotal length

The record table

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

How this table is compiled

The median entry measures 1.52 km, so half the table sits below that and half above, which is a better guide to the typical structure here than the headline figure. The shortest recorded entry is 0.06 km against 19.8 km at the top, a spread of 309.42x across the same table.

The three longest entries alone account for 52.81 km of the 188.09 km on this page, which is 28 per cent of the total from 3 of 60 rows. 30 entries sit above the median and 30 at or below it, so the table is evenly weighted and not clustered at one end.

A new scheme in the world would have to beat 19.8 km to change the head of this table, and that is the figure worth rechecking when one opens. 9 of the 60 entries fall within a quarter of the median length, which is how tightly this particular list clusters around its typical structure.

This page records the road tunnels catalogued for the world in a tunnel almanac maintained at this address since the late 1990s. Laid end to end the entries on this page would run 188.09 km, which is a number with no engineering meaning but a useful sense of the scale of what is catalogued.

The longest entry is Simplon Tunnel, at 19.8 km, opened in 1898. 68 of the 68 rows carry an entry in the tunnel type, notes column — 100 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.

Reading the figures

The next two longest are Marseille Canal, France at 18 km and St. Gotthard, Switzerland at 15 km. The table on this page runs to 68 rows and records Tunnel, Tunnel type, notes, Length and Year of construction for each of them, which is the shape the original compiler chose rather than one imposed here.

Dated entries run from 1802 to 1907, and the busiest decade is the 1820s with 8 recorded openings. Read down the length column, the 60 values run from 25 m to 19 803 m with a midpoint at 1 424 m; the spread rather than the maximum is what says how uneven this set is.

Roughly 0 of the dated entries opened in this century, which is a rough measure of how much of the network is recent. The captions name 34 distinct places and structures — Souterrain, Norway and Jerusalem among them — and those names are the index into the length tables where each is recorded with its own figure.

The shorter half of the table totals 16.74 km against 171.35 km for the longer half, from the same number of rows. The tunnel column names 67 distinct entries on this page, Under Eufrate river and Gihon - Siloa, Israel among them, each traceable to the operator or administration record it was taken from.

The dated entries carry 35 distinct opening years across 105 years, and the median opening year is 1854. The material on this page is held in 25 captions rather than in running text, 207 words of it, each written against the image or row it belongs to by the compiler who put the page together.