Tunnels and Viaducts on the A23 Motorway in Italy, by Kilometre Point

• 59entries listed
• 2.36 kmlongest bore
• 38.28 kmtotal length

The record table

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

How this table is compiled

The route table lists 59 structures with a recorded length, giving both carriageways where the two bores differ. The table on this page runs to 94 rows and records Tunnel / Viaduct, Direction Austria, Direction Palmanova, Notes and pk for each of them, which is the shape the original compiler chose rather than one imposed here.

The entries sum to roughly 38.28 km of bore, an average of about 0.65 km each, though that average describes no actual row. The tunnel / viaduct column names 76 distinct entries on this page, Cormor I° and Cormor II° among them, each traceable to the operator or administration record it was taken from.

The next two longest are Fella IX° at 0.98 km and FS Gemona at 0.96 km. The material on this page is held in 3 captions rather than in running text, 21 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 A23 in Italy, in a tunnel almanac maintained at this address since the late 1990s. The captions name 9 distinct places and structures — Pontebba, Friuli and Venezia among them — and those names are the index into the length tables where each is recorded with its own figure.

45 entries fall below a kilometre, short enough that portals and approaches usually decided their cost more than the bore itself. Pontebba at 2.28 km and Spartiacque at 1.8 km follow it, and lengths are given per carriageway because the two bores of a dual route are rarely cut to the same length.

Reading the figures

The three longest entries alone account for 6.44 km of the 38.28 km on this page, which is 17 per cent of the total from 3 of 59 rows. The shorter half of the table totals 6.17 km against 32.11 km for the longer half, from the same number of rows.

Between the longest and the tenth-longest the drop is 0.98 km, which is the part of the table that changes when a single scheme opens. Lengths for Italy are recorded in metres which is how the operators publish them and why the shortest entry here reads as 40 m and not a rounded figure.

A new scheme in Italy would have to beat 2.36 km to change the head of this table, and that is the figure worth rechecking when one opens. The longest entry is 59.0 times the shortest and 5.6 times the median, which is the quickest measure of how uneven the table is.

On 34 of the structures here the two carriageways are not the same length, which is why the archive records each direction separately rather than one figure per crossing. The note column records 10 exits, 2 motorway connections, 1 toll barriers and 2 service areas along the route, in running order rather than by size.

The note column places the route in Friuli, and the administrative area is recorded because a section is identified by it. Read down the direction austria column, the 69 values run from 10 to 21 717 with a midpoint at 335; the spread rather than the maximum is what says how uneven this set is.