Tunnels and Viaducts on the A03 Motorway in Italy, by Kilometre Point

• 23entries listed
• 0.5 kmlongest bore
• 4.62 kmtotal length

The record table

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

How this table is compiled

Between the longest and the tenth-longest the drop is 0.34 km, which is the part of the table that changes when a single scheme opens. Where one of these 23 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 41 m and not a rounded figure. The longest entry is 12.2 times the shortest and 3.3 times the median, which is the quickest measure of how uneven the table is.

A new scheme in Italy would have to beat 0.5 km to change the head of this table, and that is the figure worth rechecking when one opens. The eighth longest is Caiafa at 0.21 km, which is about where this record stops being about record holders and starts being about ordinary infrastructure.

The route table lists 23 structures with a recorded length, giving both carriageways where the two bores differ. The material on this page is held in 7 captions rather than in running text, 54 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 A03 in Italy, in a tunnel almanac maintained at this address since the late 1990s. The captions name 12 distinct places and structures — Ercolano, Portici and Salerno among them — and those names are the index into the length tables where each is recorded with its own figure.

Reading the figures

The twelfth longest, Iannone at 0.15 km, sits close enough to its neighbours that which of them ranks higher depends on how each was measured. On 1 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 next two longest are San Pantaleone at 0.48 km and San Giovanni at 0.45 km. San Pantaleone at 0.48 km and San Giovanni at 0.45 km follow it, and lengths are given per carriageway because the two bores of a dual route are rarely cut to the same length.

The table on this page runs to 23 rows and records Tunnel / Viaduct, Direction Salerno, Direction Napoli and Notes for each of them, which is the shape the original compiler chose rather than one imposed here. The oldest crossings still in service were built before any of the design codes that now govern their maintenance.

Also recorded here are Rotolo at 0.3 km and Medaglie d'Oro at 0.25 km. A tunnel list for Italy reads differently from a neighbouring country's: 0 of these 23 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 entries sum to roughly 4.62 km of bore, an average of about 0.2 km each, though that average describes no actual row. The tunnel / viaduct column names 17 distinct entries on this page, San Giovanni and Portici among them, each traceable to the operator or administration record it was taken from.