No, not the tunnel. I found a good pad that bypassed it. This was all on the Munyang side of the river. It got a bit steep in one section (and I hate sidling steep loose slopes) but there was enough scrub to use as handholds to stop me sliding down.
Of course, I was a lot fitter and stronger then. Or maybe just so determined to keep off the road that I blocked out any consideration (or memory) of the worst aspects.
It's a shorter route than going over the tops from Whites, but not really a whole lot quicker.
This gives a very rough Idea of the route I used - it was kind of spur of the moment as I'd originally planned to follow the road. Turned the GPS off during a lunch break and forgot to turn it back on again.
The zigzagging down - and I probably did more than that - was due to the gradient - it gets very steep in places.