Tunnels and Viaducts on the A15 Motorway in Italy, by Kilometre Point

• 103entries listed
• 2.05 kmlongest bore
• 27.93 kmtotal length

The record table

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

How this table is compiled

The next two longest are Punta Monte at 1.44 km and Cucchero at 1.17 km. The table on this page runs to 124 rows and records Tunnel / Viaduct, Direction La Spezia, Direction Parma, Notes and km for each of them, which is the shape the original compiler chose rather than one imposed here.

The entries sum to roughly 27.93 km of bore, an average of about 0.27 km each, though that average describes no actual row. The tunnel / viaduct column names 102 distinct entries on this page, Via Emilia and Rio Dordone among them, each traceable to the operator or administration record it was taken from.

100 entries fall below a kilometre, short enough that portals and approaches usually decided their cost more than the bore itself. Read down the direction parma column, the 101 values run from 10 to 7 865 with a midpoint at 185; the spread rather than the maximum is what says how uneven this set is.

This page records the structures catalogued along the A15 in Italy, in a tunnel almanac maintained at this address since the late 1990s. The captions name 9 distinct places and structures — Prov, Emilia and Romagna among them — and those names are the index into the length tables where each is recorded with its own figure.

The route table lists 103 structures with a recorded length, giving both carriageways where the two bores differ. The material on this page is held in 3 captions rather than in running text, 19 words of it, each written against the image or row it belongs to by the compiler who put the page together.

Reading the figures

Between the longest and the tenth-longest the drop is 1.44 km, which is the part of the table that changes when a single scheme opens. Where one of these 103 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 21 m and not a rounded figure. The longest entry is 97.8 times the shortest and 11.4 times the median, which is the quickest measure of how uneven the table is.

A new scheme in Italy would have to beat 2.05 km to change the head of this table, and that is the figure worth rechecking when one opens. The eighth longest is Gordana at 0.74 km, which is about where this record stops being about record holders and starts being about ordinary infrastructure.

The ten longest average 1 km against 0.19 km for everything below them, and that ratio is the clearest thing this table says about the distribution. 90 of them are under 500 metres, which on a route of this kind usually means a cut-and-cover section or a short spur and not a driven bore.

Only 25 of the 124 rows carry anything in the km column, so that field describes a minority of this table and the rest of the rows are recorded without it. Norway builds more subsea road tunnels than anywhere else because its coast is deep, its islands are populated and a bridge would not reach.