Tunnels and Viaducts on the R33 Motorway in Italy, by Kilometre Point

• 6entries listed
• 0.38 kmlongest bore
• 1.05 kmtotal length

The record table

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

How this table is compiled

The median entry measures 0.15 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 0.05 km against 0.38 km at the top, a spread of 7.21x across the same table.

Between the longest and the tenth-longest the drop is 0.32 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 52 m and not a rounded figure. The longest entry is 7.2 times the shortest and 2.5 times the median, which is the quickest measure of how uneven the table is.

Laid end to end the entries on this page would run 1.05 km, which is a number with no engineering meaning but a useful sense of the scale of what is catalogued. China's list grew faster in twenty years than most national lists did in a century, and its longest entries are all recent.

The next two longest are Annunziata at 0.25 km and Card at 0.2 km. 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.

Reading the figures

The entries sum to roughly 1.05 km of bore, an average of about 0.17 km each, though that average describes no actual row. A new scheme in Italy would have to beat 0.38 km to change the head of this table, and that is the figure worth rechecking when one opens.

6 entries fall below a kilometre, short enough that portals and approaches usually decided their cost more than the bore itself. Annunziata at 0.25 km and Card. Portanuova at 0.2 km follow it, and lengths are given per carriageway because the two bores of a dual route are rarely cut to the same length.

0 of the 6 entries fall within a quarter of the median length, which is how tightly this particular list clusters around its typical structure. 6 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.

The longest entry is Spirito Santo, at 0.38 km. Also recorded here are Vallone Petrara at 0.07 km and Calopinace at 0.05 km. Only Spirito Santo sits within ten per cent of the longest figure, so one structure stands 0.12 km clear of the field here.

The longest stands 0.12 km clear of the next longest, which is the margin to watch when a new scheme is announced. The note column places the route in Calabria, and the administrative area is recorded because a section is identified by it. Italian motorway inventories list tunnels and viaducts together in running order along the R33.