I drove several times 25-km tunnel in Norway. It is the single tunnel for traffic in both directions with one line in each direction. It is not scary especially

I drove several times 25-km tunnel in Norway. It is the single tunnel for traffic in both directions with one line in each direction. It is not scary especially after driving through several older narrower tunnels before. The biggest problem is that it is very borring to drive through. To make driving less borring it contains 3 huge caves lit by light with different colors. It helps, but not much.