World's longest purpose-built pedestrian tunnel?

Question

Where is the world's longest publicly accessible purpose-built pedestrian tunnel?

Wikipedia has:

• List of long tunnels by type, bicycle and pedestrian. This is incomplete, as the only long pedestrian tunnel I've been in, the 1.6 km Niwärch tunnel (photo), was unlisted until I added it. Worse, many of the entries are not pedestrian tunnels, but tunnels for disused railways now open to the public. That's cheating.
• A category on pedestrian tunnels, which is even more incomplete (only 13 entries!).

Where is the longest purpose-built pedestrian tunnel in the world? By a pedestrian tunnel, I mean a tunnel that, when built, was not designed for anything larger than a pedestrian or possibly cyclists. For example, the Niwärch tunnel counts; built for water + human but has always been publicly accessible, but does not fit anything larger than a pedestrian (the watercourse is less than a metre wide). Disused railways that are now open to foot and bike traffic don't count. For the purpose of my question, it should be a simple tunnel connecting A to B; large networks of underground pathways such as the Toronto PATH do not count, for the same reason that the Shanghai Metro does not count as the world's longest railway tunnel.

Answer 1

Your conditions are quite strict - "Longest", "publicly accessible", AND "purpose-built". A "simple tunnel connecting A to B".

There is indeed a tunnel that meets these criteria that at 1,635 metres is slightly longer than the one you've mentioned. The tunnel itself IS publicly accessible, although at the current time it's entire length is not accessible - only part of it.

For this "simple tunnel", point A is North Korea. Point B is South Korea. And the tunnel is commonly known as the 'Third Infiltration Tunnel'. It was built to allow "pedestrians" (in the form of North Korean soldiers) to travel from North Korea into South Korea. The southern end of the tunnel is currently open to the public (with restrictions around nationalities that can visit, but still...) and you can travel some way into the tunnel below the DMZ between the two countries.

Two additional, much longer tunnels in the same area meet all of your criteria except for not being publicly accessible. The first and second Infiltration Tunnels are both around 3.5km long and were purpose-built for "pedestrians". The forth Infiltration Tunnel rounds out the set, but is only around 2km long.

Answer 2

The pedestrian-part of the Galleria ENEL Alpe Croppi di Lago appears to be around 2.8 km long (and reportedly only around 1.8 metre high in places, though I'm not sure about the height in general). It is used by a variant route of the GTA and other hiking routes. It is described by this video on youtube.

Answer 3

There's a pedestrian tunnel under construction under Løvstakken, in Bergen, Norway. The length is 2900m. It's scheduled to open in 2023.

Parallelt med traseen bygges det en gang- og sykkeltunnel. Tunnelen vil bli en toveis bane med en bredde på seks meter. 3,5 meter blir sykkelfelt og 2,5 meter blir fortau.

In paralell with the [light rail] tunnel, a separate pedestrian and biking tunnel is being built. The tunnel will have two lanes [for bikes and pedestrians], with a total width of 6 meters. 3.5 meters will be bike lanes, and 2.5 meters for pedestrians.

Answer 4

Tunnel de la Croix-Rousse in Lyon, France, is a pair of tunnels, the first one for cars, the other one for sustainable transport (pedestrians, cyclists, busses). Their length is 1782m.