Tunnels

Signs

An array of signs and devices should be used to ensure proper operation of tunnels and their approach infrastructure. Appropriate regulatory signs (eg speed control); warning signs, direction signs and variable message signs may be used to meet these requirements. It is desirable to discourage unnecessary lane changing in tunnels and appropriate signs and lane marking should be considered.

Variable message signs located outside of a tunnel may be required to manage incidents in the tunnel. Lane control signs and variable speed limit signs (single or combined VSL or VSL/LCS) may be required to manage lane usage and speed over a range of operational and emergency scenarios. Traffic signals may be required to prevent entry into a tunnel when an incident occurs, where there is one lane only, or there are restrictions on the type of vehicles that can use it (eg Haitaitai bus tunnel, Wellington). See Figure 6‑7 for an example of signing and supplementary markings for tunnels. Refer also to emergency vehicle - flashing signals for information regarding the use of flashing red signals to alert road users to the need to stop as may be required for tunnels. Larger tunnels may have restrictions imposed through bylaws and further information should be sought from the relevant authorities in relation to those restrictions.

Emergency vehicle - flashing signals

For one lane priority operation, refer to one-lane bridges and other roadways otherwise, the signs described in Table 6‑5, Table 6‑6, and Table 6‑13 should also be used.

One-lane bridges and other roadways

Table 6‑5

Table 6‑6

Table 6‑13: Tunnel signs

Sign code	Example	Description/use
W13-6 Tunnel		Should be installed on those approaches to a road tunnel where the portal is not visible for a distance of at least 120m. The sign is not normally necessary in urban areas. For sign location, refer to note 1.
A50-1 General advisory - Use headlamps in tunnel		Should be located in advance of a tunnel to advise road users to use their headlamps in the tunnel. For sign location, refer to note 2.

Table 6‑13 note:

1. The sign should be installed so that approaching drivers have an uninterrupted view of it over a distance of at least 120m in rural areas and at least 60m in urban areas. The sign should be installed in advance of the tunnel portal by at least the distance shown in the table below.
   

   Operating speed	Distance
   50km/h	65m
   70km/h	100m
   80km/h	120m
   90km/h	140m
   100km/h	160m

2. The sign should normally be mounted on the tunnel portal or on the left-hand side of the roadway as close to the tunnel portal as possible.

Markings

For one lane priority operation, refer to one-lane bridges and other roadways.

One-lane bridges and other roadways