Zigana Tunnel is a dual lane, dual tunnel for each direction of traffic. You will not see oncoming traffic as the tunnel tubes are seperated. It is well lit with distinctive blue and green LED lighting on the tunnel walls and sides for visibility and orientation. Reflective green curb markers and overhead lights for lane safety. Large ceiling-mounted axial fans visible aid air circulation and smoke evacuation. If you were to cross this, best to pick weekend morning where traffic is light (I did). Turn on your rear blinkers and ride single file. If you do decide to turn around after entry, there are multiple point where you can cross over to tünel tubes on other side. Otherwise there are 16 lay-by areas about 200m long each for you to rest if required. This will give u indication of your progress.