National Roads Authority

Hi,

The NRA finally got back to me, they have only recently appointed a new Environmental Manager which caused the delay in a response.

Their brief reply states that

The approach taken to road lighting for national road schemes is set out in the Authorities Specification for Road Works. In relation to light pollution, it is normal practice on new road schemes where lighting is required to use fully horizontal cut off lighting as a means to control the impact of road lighting

I think that means that they will use fully horizontal cut off lighting in all road developments. I cant find the specification as a free download on their site, so if anyone happens to have access to these documents I'd be very grateful if you could mail them on to me

Cheers,
~Al

Al,

The NRA standard is "TD 30/87 Design of Road Lighting for all purpose Trunk Roads"

However, this standard basically states that you need to refer to British Standard "BS 5489 Road Lighting" for the detailed lighting design.

BS 5489 doesn't categorically state "Thou shall only use FCO".
Rather, it gives recommendations and guidance.

Up to recently, best practice was the real governing factor for lighting design.

However, BS 5489 will be gradually phased out shortly to be superseeded by the European Standard ISEN 13201.
In certain situations, this standard calls for a reduction in the illuminance levels on certain roadways.

One of the arguments against FCO is that it may require more lighting masts and much higher wattage bulbs. However, as we all know, there are environmental benefits to FCO also.

Virtually all new contracts for road construction issued in the last year or so by the NRA specifically state within them that FCO must be used. This is to remove any ambiguity within the design standards and would seem to indicate the position the NRA and local authorities have on this issue.

Michael

Thanks Michael,

I knew of the British standard, I just thought the NRA had their own rules in addition to these.

From talking to people in the NRA before they would not commit that thay would exclusivly use FCO's, however this letter and your post about the contracts would seem to suggest that they are planning on using them exclusivly.

For lighting a motorway you really need to use high poles to get an even spread of light anyway, so using FCO's is the obvious choice.

It is good news anyway!

Cheers,
~Al

For lighting a motorway you really need to use high poles to get an even spread of light anyway, so using FCO's is the obvious choice.

At interchanges, high masts tend to be used. Due to their height, FCO would certainly be required otherwise they'd be seen for miles around. Few would have any arguments about that.

However, low level (10-12m) lighting columns would still be needed. It's this area that causes debate. Persoanlly, I think FCO should be used. However, considerable improvements have taken place in the design of lantern design which allow for a much more efficient SCO design. This has improved to such an extent that the latest SCO lamps shine only 1-2% of theior light above the horizontal.
It should be noted that FCO does require one of the following options:
1) Closer spacing of lighting columns than SCO
2) Higher wattage lamps than SCO
or
3) A combination of the above.
The problem with using more poles is that they pose a greater risk to traffic in the event that errate vehicles hit them.
Using the same number of poles for FCO as SCO leads to an increase in energy costs due to the higher wattage lamps required.
However, the obnvious benefits of FCO should outweigh the cons.

Michael