I wouldn't say significant. The vast majority of cyclists will use it mainly (or only) to travel to and from offices/schools/universities/shops. A tunnel that's closed at night will still be really useful. Especially if the alternative is not having a tunnel due to safety concerns.
if you are going to invest 100's of millions probably better to do it right. Current idea is a bridge far away from the central station which is even more silly.
It depends on what you mean by “right”. Just because it would be “better” to have a tunnel you could use at night versus a day only one doesn’t mean a day only one wouldn’t be better than the current situation. If a day only tunnel would save money in the long term (due to replacing ferries), take pressure off of other modes of transport, and increase revenue due to induced demand allowing people who may have otherwise not traveled into out or out of the city center on a given day choosing to because of the tunnel option, then it makes sense. Not building it until you could “figure out” how to keep it open at night sounds like a “perfect being the enemy of good” situation. If 50,000 people per day would use the tunnel, not building it because 2,500 people per night couldn’t use it isn’t a good solution.
