Tunnels and Viaducts on the A8 Motorway in France, by Kilometre Point

• 86entries listed
• 1.59 kmlongest bore
• 1969–1992openings span
• 30.71 kmtotal length

The record table

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

How this table is compiled

Between the longest and the tenth-longest the drop is 0.98 km, which is the part of the table that changes when a single scheme opens. Where one of these 86 lengths disagrees with an operator's own figure for France, the table keeps the published value and notes the difference instead of averaging the two.

Lengths for France are recorded in metres which is how the operators publish them and why the shortest entry here reads as 30 m and not a rounded figure. The longest entry is 53.0 times the shortest and 5.4 times the median, which is the quickest measure of how uneven the table is.

The 89 entries are grouped on the page under 19 headings — exit 59 menton (16), toll barrier la turbie (13), exit 54 nice nord (10), exit 46 bouches de loup (8) and exit 37 puget sur arggens (4) — a classification the table carries as section breaks rather than as a column of its own.

The next two longest are Las Planas at 1.11 km and L’Arme at 1.11 km. The table on this page runs to 89 rows and records Tunnel / Viaduct, Direction Aix en Provence, Direction Italy and Notes for each of them, which is the shape the original compiler chose rather than one imposed here.

Roughly 0 of the dated entries opened in this century, which is a rough measure of how much of the network is recent. Only 50 of the 89 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.

Reading the figures

Dated entries run from 1969 to 1992, and the busiest decade is the 1970s with 11 recorded openings. The material on this page is held in 10 captions rather than in running text, 85 words of it, each written against the image or row it belongs to by the compiler who put the page together.

The longest stands 0.48 km clear of the next longest, which is the margin to watch when a new scheme is announced. The direction aix en provence column names 50 distinct entries on this page, 455 m and 140 m among them, each traceable to the operator or administration record it was taken from.

Also recorded here are Canta-Galet at 0.62 km and L'Oli at 0.61 km. A tunnel list for France reads differently from a neighbouring country's: 0 of these 86 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.

42 entries sit above the median and 44 at or below it, so the table is top-heavy and not clustered at one end. The captions name 17 distinct places and structures — Italian, France and Alpes among them — and those names are the index into the length tables where each is recorded with its own figure.

A new scheme in France would have to beat 1.59 km to change the head of this table, and that is the figure worth rechecking when one opens. The eighth longest is Castellar at 0.58 km, which is about where this record stops being about record holders and starts being about ordinary infrastructure.