Road Tunnels in Taiwan — Complete List by Length

• 97entries listed
• 12.94 kmlongest bore
• 1974–2009openings span
• 73.44 kmtotal length

The record table

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

How this table is compiled

The three longest entries alone account for 21.74 km of the 73.44 km on this page, which is 30 per cent of the total from 3 of 86 rows. 43 entries sit above the median and 43 at or below it, so the table is evenly weighted and not clustered at one end.

Where one of these 86 lengths disagrees with an operator's own figure for Taiwan, the table keeps the published value and notes the difference instead of averaging the two. The 86 rows for Taiwan are ordered by length, not by date, so the 2009 opening sits well down the table without being any less current.

Lengths for Taiwan 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 longest entry is 86.3 times the shortest and 27.2 times the median, which is the quickest measure of how uneven the table is.

A new scheme in Taiwan would have to beat 12.94 km to change the head of this table, and that is the figure worth rechecking when one opens. Eighth on the list is Jhongliao at 1.86 km, which is where the table stops being about record holders and starts being about ordinary infrastructure.

Dated entries run from 1974 to 2009, and the busiest decade is the 2000s with 20 recorded openings. The table on this page runs to 97 rows and records Tunnel, Length (m), Date of opening, County and Notes for each of them, which is the shape the original compiler chose rather than one imposed here.

Reading the figures

1 of the 86 measured entries exceed five kilometres, and those are the ones that carry a full ventilation and escape regime. Laid end to end the entries on this page would run 73.44 km, which is a number with no engineering meaning but a useful sense of the scale of what is catalogued.

1 entries reach ten kilometres and 0 reach twenty, a distribution that decides how much of this table needs full mechanical ventilation. Only 45 of the 97 rows carry anything in the date of opening column, so that field describes a minority of this table and the rest of the rows are recorded without it.

Roughly 20 of the dated entries opened in this century, which is a rough measure of how much of the network is recent. The captions name 4 distinct places and structures — Pinglin, Hsinhai and Dahan-Wunshan among them — and those names are the index into the length tables where each is recorded with its own figure.

The dated entries carry 10 distinct opening years across 35 years, and the median opening year is 2000. Read down the length (m) column, the 97 values run from 150 m to 12 942 m with a midpoint at 500 m; the spread rather than the maximum is what says how uneven this set is.

The material on this page is held in 12 captions rather than in running text, 93 words of it, each written against the image or row it belongs to by the compiler who put the page together. Ventilation and escape provision, not bore length, drive most of the cost on modern road tunnels in Taiwan.