Tunnels and Viaducts on the A36 Motorway in Italy, by Kilometre Point

• 44entries listed
• 17.41 kmtotal length

The record table

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

How this table is compiled

The material on this page is held in 10 captions rather than in running text, 108 words of it, each written against the image or row it belongs to by the compiler who put the page together. The kilometre point is recorded for each structure on the A36, which is how the operator identifies it.

They are not uniform: the fullest runs to 19 words and the briefest to 6, and on a page of this kind the long ones are where the explanation lives — the caption carries what the picture cannot. A crossing whose two carriageways differ in length is recorded once per direction rather than once per crossing.

The tunnel / viaduct column names 57 distinct entries on this page, Artificiale Venegoni (C&C) and Artificiale S.P. 2 (C&C) among them, each traceable to the operator or administration record it was taken from. A single-track bore costs less than half a double-track one and constrains the timetable for the next century.

Read down the direction a4 column, the 56 values run from 15 to 1 447 with a midpoint at 205; the spread rather than the maximum is what says how uneven this set is. A disused tunnel is expensive to fill and cheap to seal, which is why so many survive behind a wall.

Read down the direction a8 column, the 56 values run from 15 to 1 447 with a midpoint at 205; the spread rather than the maximum is what says how uneven this set is. A figure quoted to the metre implies a survey that was actually done, and not every published length carries one.

Reading the figures

A tunnel list for Italy reads differently from a neighbouring country's, because the same journey time can be bought with one long bore in one country and a dozen short ones in another. A pilot bore driven ahead of the main tunnel buys knowledge of the ground and is often kept afterwards as the escape route.

The note column records 22 exits, 8 motorway connections, 1 toll barriers and 1 service areas along the route, in running order rather than by size. The route crosses 3 provinces, recorded in the note column by their vehicle-registration codes (CO, MB, VA), which is how the operator identifies a section.

Italian motorway inventories list tunnels and viaducts together in running order along the A36. Tunnel building in Italy is shaped by geology and settlement pattern as much as by transport policy. A concrete arch takes its load into the abutments, so it needs rock at both ends and appears where valleys are steep and narrow.

Where a structure has been lengthened by a later extension, the current figure is the one shown. Cross-passage spacing, not bore length, is what modern safety regulation actually governs. Tunnel openings arrive in waves, not at a steady rate, because contracts along a corridor are usually let together once a route has been funded.

Subsea tunnels are usually built with a low point well below sea level and pumped continuously. Smoke behaves differently on a gradient, and the uphill portal of a burning tunnel is the dangerous one. Sequential excavation takes the face in slices, which is slower per metre and far more tolerant of ground that changes.