Tunnels and Viaducts on the A51 Motorway in Italy

The 12 entries are grouped on the page under 10 headings — exit 20 – arcore - villasanta sp 45 (3), exit 1 – san donato milanese (1), exit 5 - c.a.m.m. (1), exit 8 - lambrate - sp103 rivoltana (1) and exit 10 – via palmanova (1) — a classification the table carries as section breaks rather than as a column of its own.

This page records the structures catalogued along the A51 in Italy, in a tunnel almanac maintained at this address since the late 1990s. Only 5 of the 12 rows carry anything in the tunnel / viaduct column, so that field describes a minority of this table and the rest of the rows are recorded without it.

The route table lists 4 structures with a recorded length, giving both carriageways where the two bores differ. The material on this page is held in 11 captions rather than in running text, 79 words of it, each written against the image or row it belongs to by the compiler who put the page together.

4entries listed
3.34 kmlongest bore
5.15 kmtotal length

The record table

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

Tunnels and Viaducts on the A51 Motorway in Italy, by Kilometre Point
Tunnel / Viaduct	Direction San Donato M.se	Direction Usmate	Notes
			Connection A1 Milano - Bologna, Connection A50 Tangenziale Ovest; Reg. Lombardy – Prov. MI
			Exit 1 – San Donato Milanese
San Donato	853 m	853 m
			Exit 2 - SS 9 Via Emilia
			Exit 3 - SS415 - Paullo - MM3 San Donato
			Exit 4 - Via Mecenate
			Exit 5 - C.A.M.M.
Dei Parchi	2 896 m	3 342 m
			Exit 6- Linate Airport – V.le Forlanini (on viaduct)
			Exit 7 - Via Rubattino (on viaduct)
			Exit 8 - Lambrate - SP103 Rivoltana
	Agip	Agip	Service Areas "Cascina Gobba"
			Exit 9 – Via Padova - Gobba MM2
			Exit 10 – Via Palmanova
	-		Connection A52 Tangenziale Nord Sesto S.G. - Paderno D.
			Exit 11 - Cologno Monzese Sud
			Exit 12 – Cologno Monzese Nord
	-	Totalerg	Service Area "Cologno Est"
			Exit 13 – Cernusco / Brugherio SP 113
			Exit 14 - Carugate
	Tamoil	Tamoil	Service Areas "Carugate"
			Toll barrier Agrate
			Connection A4 Torino - Trieste
			Exit 15 - Agrate
			Exit 16 – Monza SP13 - Custom Concorezzo
		-	Exit 17 - Concorezzo
			Exit 18 – Burago SP 200
			Exit 19 – Vimercate Sud
			Exit 20 – Arcore - Villasanta SP 45
		-	Exit 21 – Vimercate Centro
Vimercate I	150 m	150 m
Vimercate II	800 m	800 m
			Exit 22 – Vimercate Nord
			Exit 23 – Carnate SP 117
			Exit 24 – Usmate Velate Sud
	Agip	-	Service Area "Vimercate Ovest"
			Connection SS 342 dir
TOTAL tunnel	950	950

How this table is compiled

38 rows are rendered in total, so 34 of them carry a note or a blank where a length belongs and are shown without being counted. The middle half of the table runs from 0.31 km to 2.72 km, and that band is where most of the engineering on this page actually sits.

The median entry measures 0.83 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 0.15 km against 3.34 km at the top, a spread of 22.28x across the same table.

The longest stands 2.49 km clear of the next longest, which is the margin to watch when a new scheme is announced. The captions name 27 distinct places and structures — Tangenziale, Milano and Bologna among them — and those names are the index into the length tables where each is recorded with its own figure.

3 entries fall below a kilometre, short enough that portals and approaches usually decided their cost more than the bore itself. The direction san donato m.se column names 8 distinct entries on this page, 853 m and 2 896 m among them, each traceable to the operator or administration record it was taken from.

Where one of these 4 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 22.3 times the shortest and 4.0 times the median, which is the quickest measure of how uneven the table is.

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 150 m and not a rounded figure. The note column records 24 exits, 5 motorway connections, 1 toll barriers and 2 service areas along the route, in running order rather than by size.

The next two longest are San Donato at 0.85 km and Vimercate II at 0.8 km. San Donato at 0.85 km and Vimercate II at 0.8 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 entries sum to roughly 5.15 km of bore, an average of about 1.29 km each, though that average describes no actual row. A new scheme in Italy would have to beat 3.34 km to change the head of this table, and that is the figure worth rechecking when one opens.

Laid end to end the entries on this page would run 5.15 km, which is a number with no engineering meaning but a useful sense of the scale of what is catalogued. The note column places the route in Lombardy, and the administrative area is recorded because a section is identified by it.

The table on this page runs to 12 rows and records Tunnel / Viaduct, Direction San Donato M.se, Direction Usmate and Notes for each of them, which is the shape the original compiler chose rather than one imposed here. Tunnel building in Italy is shaped by geology and settlement pattern as much as by transport policy.

Questions about Italy

What is the longest structure in Italy?

On the figures recorded here it is Dei Parchi, at 3.34 km. It is the longest of the 4 entries recorded here, measured by bore length rather than span, cost or construction difficulty.

How many structures are listed for Italy?

4 entries with a recorded length appear on this page, from 0.15 km at the short end to 3.34 km at the top, with the middle of the set around 0.83 km. The table renders 38 rows in total; the rest carry a note or a blank where a length belongs.

What is a typical length among the structures listed for Italy?

The median entry measures 0.83 km and the middle half of the table runs from 0.31 km to 2.72 km. The headline figure of 3.34 km is the outlier, not the norm, which is why the median is the more useful number when comparing one national list against another.

How close is the top of the Italy table?

The longest stands 2.49 km clear of the next entry, and nothing else comes within ten per cent of it. A newly announced scheme therefore has to beat 3.34 km to displace Dei Parchi.

How many structures does this route carry?

4 named tunnels and viaducts have a recorded length on this route, the longest being Dei Parchi at 3.34 km, followed by San Donato at 0.85 km and Vimercate II at 0.8 km; 1 of the 4 are under 500 metres.

Other pages in this section

Cite this page

Tunnels and Viaducts on the A51 Motorway in Italy, by Kilometre Point. The World's Longest Tunnels. https://www.lotsberg.net/data/italia/A51.html

Tunnels and Viaducts on the A51 Motorway in Italy, by Kilometre Point