More thoughts on tunnel signage and tunnel safety

In this article, I give more thoughts on tunnel signage as well as tunnel safety.  For me, metrication is a big must, and the only thing really needed, as well as ensuring the signs are as clutter free as possible, and which respect international standards, specifically SI (metric system) and the Vienna Convention on Road Signs and Signals.

Tunnel entrances

I found this on Wikipedia, on an image of the (Mersey) Queensway Tunnel, a metric distance sign in use in the UK, when looking for tunnel entrance images in use in the UK. For some reason, the sign is on the right hand side of the road only, and apart from lack of space, I wonder why this is. This gives an example of such a tunnel entrance sign, and it is already metric:

Warning sign meaning Queensway / Birkenhead tunnel ahead.
The tunnel length is 3420m.

Since this sign is already metric, this does not really require change, and I think this type of sign is perfectly good for a tunnel entrance sign. However, what I would suggest is that the actual length symbol be used, to make it clear and unambiguous that the measurement shown is the length of the tunnel, and cannot be confused with "3240m ahead".  So that the supplementary plate would say "Mersey Queensway ↑ 3240m ↑":

Queensway / Birkenhead tunnel, the tunnel length is 3420m.
The sign above makes it clear that 3420m is a length (not the distance ahead).

Personally, I am perfectly happy for this sign to remain as is, and the same approach is used in Sweden and Norway, according to this comparison.  I do have one question though, apart from lack of space, I do wonder why does this metric sign only appears on the right hand side of the road.

However, it is worth noting that technically the tunnel in a red triangle means "Warning of a tunnel".  If there ever was the need to distinguish "Tunnel ahead" with "Tunnel regulations start here", we could consider using the sign shown in the example below, as is used in France, Germany, and in fact the vast majority of the countries in Europe (regardless of whether these countries are in or out of EU):

About to enter the Anytown tunnel.
The tunnel length is 3582m.
This sign is not used in the UK.

The above has been included for completeness, to see what British designs of such signs could look like.  My opinion though, is that the existing designs, with the red triangle warning of the tunnel and the name and length of the tunnel in a supplementary plate, are fine and can be left as is.

Metrication of signs warning of a tunnel ahead (mandatory)

Of course, what is compulsory, is that a warning sign showing the tunnel a certain distance ahead needs to be metricated, an example is as shown below:

Tunnel 300m ahead, after metrication.

Metrication of restrictions signs (mandatory)

And of course, the signs showing restrictions on entering a tunnel need to be metricated as part of a general metrication programme, as illustrated in this article (the same article also pointed out a serious error on the sign itself). Metrication has to happen. In addition regarding the text "TUNNEL RESTRICTIONS", superfluous words can either be removed or replaced with symbolic equivalent, or more helpful wording (e.g. in the example in the link, Rotherhithe tunnel, or symbol of tunnel with Rotherhithe next to it).

Following distances (Suggested new signs)

In a tunnel, one can also consider higher following limits for lorries, and higher still for lorries carrying hazardous materials or water pollutants (which would either need its own sign, or supplementary plate).  For example for cars it could be 100m, for lorries 150m, for lorries carrying hazardous materials 200m, but the actual distances can vary from tunnel to tunnel depending on speed, conditions, road classification, etc.

Below are example following restriction signs which were shown in one of our previous articles here:

70 m minimum following distance for vehicles 3.5 t or heavier

80 m minimum following distance for motor vehicles

Outside tunnels (and as an aside, mountain passes), I cannot see the following distance restriction signs being used anywhere else, and I don't believe they should be either in my opinion.

The overriding priority should be to improve tunnel safety

Note that the overriding priority however must be to ensure and improve tunnel safety, including by modernising the tunnels (many of which were built a long time ago, in Victorian times, and at an age when traffic levels were much lower). Furthermore, back in 2002, there was a report saying that some UK tunnels had been rated among the worst in Europe for safety.

I understand that in the UK, work is (or was) in progress in the UK to upgrade tunnels to match European safety standards, judging by this article on the Queensway tunnel. In general anything that helps improve safety in tunnels should be incorporated.

But one should not ignore signage. This is because clear, unambiguous, symbolic signage which is understood internationally can be read at a glance, be understood straight away, and therefore can potentially help improve safety. In addition, maintaining a safe following distance can only help in that regard. Where applicable, signs to remind people dipped headlights are required and when to turn them off on exit can also be considered (graphical is best of course), but only if actually needed. As well as this the motorists also need to be aware of what to do in the event of an emergency in a tunnel. All these measures should help.

From my experience, I have driven through the numerous tunnels between Nice and Monaco and they were well lit (not only on the top, and with numerous overhead electronic signage, but there was also lighting on the sides) and the signs (both before and in the tunnel) were easy to understand.