Tunnels and Viaducts on the R04 Motorway in Italy, by Kilometre Point

• 6entries listed
• 0.58 kmlongest bore
• 1.69 kmtotal length

The record table

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

How this table is compiled

The median entry measures 0.21 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 0.07 km against 0.58 km at the top, a spread of 8.08x across the same table.

Between the longest and the tenth-longest the drop is 0.51 km, which is the part of the table that changes when a single scheme opens. Where one of these 6 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 72 m and not a rounded figure. The longest entry is 8.1 times the shortest and 2.7 times the median, which is the quickest measure of how uneven the table is.

This page records the structures catalogued along the R04 in Italy, in a tunnel almanac maintained at this address since the late 1990s. Laid end to end the entries on this page would run 1.69 km, which is a number with no engineering meaning but a useful sense of the scale of what is catalogued.

The table below lists 6 entries with a recorded length, each giving a name, a length in metres and, where documented, the year of opening. A new scheme in Italy would have to beat 0.58 km to change the head of this table, and that is the figure worth rechecking when one opens.

Reading the figures

The entries sum to roughly 1.69 km of bore, an average of about 0.28 km each, though that average describes no actual row. The tunnel / viaduct column names 7 distinct entries on this page, Passo d’Avenco and Masseria* among them, each traceable to the operator or administration record it was taken from.

The 7 entries are grouped on the page under 3 headings — piemont – prov. vc (5), slipway albiano (1) and connection a5 torino - aosta (1) — a classification the table carries as section breaks rather than as a column of its own. Italian motorway inventories list tunnels and viaducts together in running order along the R04.

The table on this page runs to 7 rows and records Tunnel / Viaduct, Length (m) Direction Ivrea, Length (m) Direction Santhià and Notes for each of them, which is the shape the original compiler chose rather than one imposed here. Tunnel building in Italy is shaped by geology and settlement pattern as much as by transport policy.

A tunnel list for Italy reads differently from a neighbouring country's: 0 of these 6 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. Where a tunnel crosses an international border, it is listed under both countries.

The longest entry is Passo d’Avenco, at 0.58 km. The longest stands 0.06 km clear of the next longest, which is the margin to watch when a new scheme is announced. 6 entries fall below a kilometre, short enough that portals and approaches usually decided their cost more than the bore itself.