Illumination of speed limit signs on side roads

[Haydn1971]

From a discussion at work the other day....

Item 10 requires terminal signs to diagrams 670, 671, 672 and 673 sited on trunk and principal roads (other “A” roads) to be illuminated by internal or external lighting throughout the hours of darkness when they are located within 50 m of a street lamp

This of course means that speed limit terminals on B and unclassified roads don't need to be illuminated, however.... what about terminal signs for drivers turning off of the main A/Trunk road into a B/Uc road ?

Now I can't recall what I've done in the past, but my translation currently is that terminal signs on the side roads of an A/Trunk road should be directly illuminated, but get the feeling I've actually done it both ways in the past... Looking at my old schemes in street view it tends to err on the illuminate the side road signs, but I seem to recall a scheme recently that Bryn did for me where I said we didn't have to illuminate

Any thoughts from sign designers on this ?

[M4Mark]

This of course means that speed limit terminals on B and unclassified roads don't need to be illuminated, however.... what about terminal signs for drivers turning off of the main A/Trunk road into a B/Uc road ?

Now I can't recall what I've done in the past, but my translation currently is that terminal signs on the side roads of an A/Trunk road should be directly illuminated, but get the feeling I've actually done it both ways in the past... Looking at my old schemes in street view it tends to err on the illuminate the side road signs, but I seem to recall a scheme recently that Bryn did for me where I said we didn't have to illuminate.
Any thoughts from sign designers on this ?

My thoughts on this:
1.Are there street lights present at all within 50m on either the main or side road?
If yes then I would most likely illuminate the signs subject to my 2nd thought, if not then no as if no street lights then cost to client to install a new electric supply may be prohibitive and unnecessary.

2:Does Item 10 or Item 11 apply? Subjective decision this one as I may consider that the sign is technically placed on the side road and not the main road so that Item 10 no longer applies and Item 11 actually applies which gives you the option not to illuminate. Chapter 3 advises:

Other terminal signs, i.e. those on unlit roads and those on lit roads that are not trunk or principal roads, must be either directly lit or reflectorised (Schedule 17, Item 11). Where a road has a system of street lighting, but is not a trunk or principal road, it is recommended that speed limit terminal signs are directly lit. Although this is not a specific requirement of the Regulations, it would minimise the risk of drivers failing to see them.

So illumination of the terminal signs is dependent upon the proximity of street lighting and the which of Item 10 or 11 is applicable to the location of the sign.

[Conekicker]

As Mark says, if it's within 50m of a streetlighting system, I'd light them. Given the angle a turning vehicle is likely to be coming in at, the retroreflective material probably won't be at the optimum angle, so the light ensures drivers will see it - no chance to then claim "What speed limit sign, officer?".

[traffic-light-man]

It always seemed illogical to me to have the rules whereby the sign must be lit within the 50m from a street light. It makes more sense in my mind the other way around, as the light from the lantern would light the sign.

But was this done just for the reason that its more logical from the power source point of view?

[Bryn666]

But light from the lantern doesn't light the sign... that's why you have to have extra illumination as the streetlighting drowns out signs.

[traffic-light-man]

Ah I see. Hence the reflectivity being more apparent when the sign is unlit by street lighting?

[M4Mark]

But light from the lantern doesn't light the sign... that's why you have to have extra illumination as the streetlighting drowns out signs.

The following reasons were given to me when I started as to why signs were generally illuminated if in street lit areas:
1. There was historically and possibly still is as I understand it the ability in law to drive on side lights only at night in a street lit area (Why you'd want to escapes me but as I understand it you can). Thus there would be no light from the headlights for the reflective material to work with. (Original reflective materials were less effective as well when the illumination regs were first written back in the 60's). Outside street lit areas headlights were required so direct illumination not.

2. If a sign is installed within 50m of a lamp column, don't assume the light from said column shines on the face of the sign, the column could be behind the sign or the pattern of light from a sequence of columns could leave the sign face in shadow, thus requiring illumination.

[boing_uk]

Well the way that I was tought and indeed how LCC did it for the HA when they were agents and of course how our signs section at the time interpreted it as was that as the signs are for and indeed ON the side road, then they are not subject to the same lighting requirements - assuming of course that the side road is not itself an A-class road.

Its all very well putting in additional lighting, but that comes at a fairly significant cost to the local authority and you may find that the street lighting guys will take your lantern away in a few years.

One anomaly which has recently come to light from our investigations at work is that plain faced bollards didnt seem to be required to be illuminated. Whether this is true or not I have yet to discover, but from cursory reading that seems to be so. And on the flip side of that coin; why on earth do shared path cycle signs need to be illuminated?

But the fact is that the cost of sign lighting is a surprising proportion of a street lighting budget; a proportion we could really do without spending on superfluous lighting of signs.

[traffic-light-man]

A plain face bollard doesn't hold a sign of legal meaning though, whereas others do, perhasps this is the reasoning? Despite this, retro-reflective plain faced bollards always seem to come with a plain face circle none the less.

Furthermore, I have not seen a shared cycle path sign that is illuminated for a while. I know there are some around, but thats in a scheme where all the signs appear to be lit, and I can't for the life of me remember where it is!

[M4Mark]

One anomaly which has recently come to light from our investigations at work is that plain faced bollards didnt seem to be required to be illuminated. Whether this is true or not I have yet to discover, but from cursory reading that seems to be so.

That is correct, I researched this a few years ago when I was researching the different non-illuminated bollards and authorisation required and found no legal requirement to illuminate a plain face bollard. If I remember correctly I spoke to DfT Traffic Signs who confirmed it (I may have even mentioned it on here when I found out).
This was confirmed in writing last year when TRL published their "Guidance on the lighting requirements for traffic signs and bollards"
(J Cooper, J Mitchell 2009) available to purchase or download Click Here.

In which they confirm that

It should be noted that the single sided Opal/Plain Face type of traffic bollard is exempt from the above criteria and requires no authorisation for its use in any location regardless of street lighting provision, because it carries no traffic sign.

[AndyB]

It is still legally permissible in Great Britain to drive on sidelights only in built-up areas after dark. Thankfully, in one of Northern Ireland's more enlightened (or less unenlightened) moments, the requirement to use at least dipped headlights after dark or in poor visibility is absolute.

The result for us is that sidelights have no practical use while driving as they're not needed in good visibility and legally inadequate in poor visibility - so they truly are parking lights only. I was still shocked to see a car behind me driving on sidelights only in the horrible weather a few days ago.

[flyingscot]

From a discussion at work the other day....

Item 10 requires terminal signs to diagrams 670, 671, 672 and 673 sited on trunk and principal roads (other “A” roads) to be illuminated by internal or external lighting throughout the hours of darkness when they are located within 50 m of a street lamp

This of course means that speed limit terminals on B and unclassified roads don't need to be illuminated, however.... what about terminal signs for drivers turning off of the main A/Trunk road into a B/Uc road ?

There are a surprising number of unlit trunk and principal speed limit signs around these days for Mr Loophole to use. I'd say if the sign is on the trunk road (i.e) slip still under motorway regs, safer to illuminate than not bother.