Road Tunnels in Portugal — Complete List by Length

• 78entries listed
• 5.83 kmlongest bore
• 1955–2019openings span
• 84.22 kmtotal length

The record table

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

How this table is compiled

The three longest entries alone account for 12.08 km of the 84.22 km on this page, which is 14 per cent of the total from 3 of 65 rows. The shorter half of the table totals 23.92 km against 60.3 km for the longer half, from the same number of rows.

Where one of these 65 lengths disagrees with an operator's own figure for Portugal, the table keeps the published value and notes the difference instead of averaging the two. The 65 rows for Portugal are ordered by length, not by date, so the 2019 opening sits well down the table without being any less current.

Lengths for Portugal are recorded in metres which is how the operators publish them and why the shortest entry here reads as 506 m and not a rounded figure. The longest entry is 11.5 times the shortest and 5.4 times the median, which is the quickest measure of how uneven the table is.

A new scheme in Portugal would have to beat 5.83 km to change the head of this table, and that is the figure worth rechecking when one opens. The dated entries fall across 18 different years, which is a rough measure of whether this was a sustained programme or a handful of separate schemes.

Dated entries run from 1955 to 2019, and the busiest decade is the 2000s with 41 recorded openings. The table on this page runs to 78 rows and records Tunnel, Length (m), Date of opening, District and Notes for each of them, which is the shape the original compiler chose rather than one imposed here.

Reading the figures

Second and third place go to Faial at 3.17 km and Encumeada at 3.09 km. Read down the length (m) column, the 78 values run from 506 m to 8 600 m with a midpoint at 1 148 m; the spread rather than the maximum is what says how uneven this set is.

1 of the 65 measured entries exceed five kilometres, and those are the ones that carry a full ventilation and escape regime. Laid end to end the entries on this page would run 84.22 km, which is a number with no engineering meaning but a useful sense of the scale of what is catalogued.

Roughly 50 of the dated entries opened in this century, which is a rough measure of how much of the network is recent. The captions name 63 distinct places and structures — Jorge, Arco and Lisboa among them — and those names are the index into the length tables where each is recorded with its own figure.

The dated entries carry 18 distinct opening years across 64 years, and the median opening year is 2004. The material on this page is held in 36 captions rather than in running text, 334 words of it, each written against the image or row it belongs to by the compiler who put the page together.

Eighth on the list is São Vicente at 2.4 km, which is where the table stops being about record holders and starts being about ordinary infrastructure. The ten longest average 2.89 km against 1.01 km for everything below them, and that ratio is the clearest thing this table says about the distribution.