Tunnels and Viaducts on the A09 Motorway in Italy, by Kilometre Point

• 15entries listed
• 0.7 kmlongest bore
• 4.33 kmtotal length

The record table

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

How this table is compiled

The next two longest are Quarcino at 0.16 km and Brogeda II° at 0.13 km. The table on this page runs to 20 rows and records Tunnel / Viaduct, Direction P.te Chiasso, Direction Lainate and Notes for each of them, which is the shape the original compiler chose rather than one imposed here.

The three longest entries alone account for 1.91 km of the 4.33 km on this page, which is 44 per cent of the total from 3 of 15 rows. The shorter half of the table totals 0.83 km against 3.49 km for the longer half, from the same number of rows.

The route table lists 15 structures with a recorded length, giving both carriageways where the two bores differ. The material on this page is held in 9 captions rather than in running text, 93 words of it, each written against the image or row it belongs to by the compiler who put the page together.

This page records the structures catalogued along the A09 in Italy, in a tunnel almanac maintained at this address since the late 1990s. The captions name 23 distinct places and structures — Como, Chiasso and Exit among them — and those names are the index into the length tables where each is recorded with its own figure.

15 entries fall below a kilometre, short enough that portals and approaches usually decided their cost more than the bore itself. Read down the direction lainate column, the 13 values run from 75 to 2 056 with a midpoint at 250; the spread rather than the maximum is what says how uneven this set is.

Reading the figures

Between the longest and the tenth-longest the drop is 0.54 km, which is the part of the table that changes when a single scheme opens. Where one of these 15 lengths disagrees with an operator's own figure for Italy, the table keeps the published value and notes the difference instead of averaging the two.

Lengths for Italy are recorded in metres which is how the operators publish them and why the shortest entry here reads as 65 m and not a rounded figure. The longest entry is 10.8 times the shortest and 3.5 times the median, which is the quickest measure of how uneven the table is.

A tunnel list for Italy reads differently from a neighbouring country's: 0 of these 15 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. The Faroese crossings connect islands that had no fixed link at all within living memory.

The entries sum to roughly 4.33 km of bore, an average of about 0.29 km each, though that average describes no actual row. A new scheme in Italy would have to beat 0.7 km to change the head of this table, and that is the figure worth rechecking when one opens.

The longest stands 0.09 km clear of the next longest, which is the margin to watch when a new scheme is announced. Laid end to end the entries on this page would run 4.33 km, which is a number with no engineering meaning but a useful sense of the scale of what is catalogued.