It’s an interesting idea Erena, but one that has its own challenges; we did a post on this previously: https://cyclingchristchurch.co.nz/2016/08/14/can-we-put-cyclists-through-lyttelton-tunnel/

I recall seeing a bike-fixup person with an inflated spanner-balloon doing the route, and that there were a lot of people.

Coincidentally I’d also done the same in the late 90s when the tunnel was opened, but that time I roller-bladed through. I do recall how much dirter the tunnel was in the 2014 event – the porcelain tiles were much cleaner and brighter in the 90s, though to be fair, 2014 was only three years post quake and there was a lot still going on.

The tunnel openings are a rare event and well-worth attending.