Why are there double dotted lines in the tunnel?

Double dotted lines have been established to allow for two-way traffic in each tunnel tube. This typically occurs during maintenance work.

The double dotted lines in the tunnel have been established to allow traffic to be diverted in each tunnel tube.

In normal traffic conditions, where both lanes travel in the same direction, the lines act as normal dotted lines.

In the case of two-way traffic, i.e., oncoming traffic in the tunnel tubes, the lines function as double lines, where overtaking is not allowed.

Two-way traffic typically occurs during maintenance work in the tunnel.