Tunnels and Viaducts on the R30 Motorway in Italy, by Kilometre Point

• 5entries listed
• 2.29 kmlongest bore
• 2.88 kmtotal length

The record table

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

How this table is compiled

4 entries fall below a kilometre, short enough that portals and approaches usually decided their cost more than the bore itself. Cologna at 0.28 km and Salva at 0.17 km follow it, and lengths are given per carriageway because the two bores of a dual route are rarely cut to the same length.

Where one of these 5 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. The longest entry is 45.7 times the shortest and 13.5 times the median, which is the quickest measure of how uneven the table is.

The entries sum to roughly 2.88 km of bore, an average of about 0.58 km each, though that average describes no actual row. A fault zone crossed at an angle is longer to pass through than the same fault crossed square, which is why alignments bend for reasons the map does not show.

The table on this page runs to 6 rows and records Tunnel / Viaduct, Length (m) Direction Salerno, Length (m) Direction Avellino and Notes for each of them, which is the shape the original compiler chose rather than one imposed here. Toll arrangements are excluded here, because they change far more often than the structures do.

This page records the structures catalogued along the R30 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 2.88 km, which is a number with no engineering meaning but a useful sense of the scale of what is catalogued.

Reading the figures

Lengths for Italy are recorded in metres which is how the operators publish them and why the shortest entry here reads as 50 m and not a rounded figure. 1 of the 5 entries fall within a quarter of the median length, which is how tightly this particular list clusters around its typical structure.

The 6 entries are grouped on the page under 2 headings — slipway baronissi (5) and slipway serino (1) — a classification the table carries as section breaks rather than as a column of its own. Gradient inside a road tunnel is kept gentle for heavy vehicles, which lengthens the bore to gain the same height.

Read down the length (m) direction avellino column, the 6 values run from 50 m to 2 454 m with a midpoint at 184 m; the spread rather than the maximum is what says how uneven this set is. Tunnel building in Italy is shaped by geology and settlement pattern as much as by transport policy.

Italian motorway inventories list tunnels and viaducts together in running order along the R30. A tunnel list for Italy reads differently from a neighbouring country's: 0 of these 5 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.

A new scheme in Italy would have to beat 2.29 km to change the head of this table, and that is the figure worth rechecking when one opens. Only Monte Pergola sits within ten per cent of the longest figure, so one structure stands 2.01 km clear of the field here.