´óÏó´«Ã½

*ping!* An email arrives;

I was puzzled by your piece on ´óÏó´«Ã½ Midlands Today about dimmable street lighting in Worcestershire. The experts said that the lower levels would be indiscernible to the human eye. If this is the case, why aren't the lights set at that level all the time - saving even more energy and public money? It seems such an obvious question. Pity you never asked it. Regards, Bob Haywood.

Thanks Bob! Well of course it IS an obvious question and it only occurred to me as I was walking back to the car. So what's the answer? I put in a quick call to one of our guests from last night, Derek Powell from Worcestershire County Council.
Now according to him although the human eye can't detect the difference in light levels the level of dimming is measured by detectors which can. And there are strict rules about the light levels for roads based on the amount of traffic at various times of day.
The rules allow Wocestershire County Council to dim the lights on the stretch of road because there are just 1000 cars using it between midnight and 6am. During the rest of the day some 22,000 vehicles travel along the A44 at this and the requirement is the light should be brighter. Those levels are not set by eye, but by electronic meter.
Mr Powell says often the first question the police ask him after an accident is did the lighting meet the British code? If it didn't then there is a chance the police could bring a charge of corporate manslaughter.
So the rules set the levels and even though we can't tell the difference, light meters and the police can. Mr Powell has actually asked the governing body to look into all this. These regulations were set in the early days of the introduction of these lights and they may well be changed and updated in the future.
So the final question is am I dimmer than Worcestershire County Councils dimable streetlamps? Well I can only say in my defence that standing around in the very cold means perhaps my brain wasn't working at peak efficiency. But we got there in the end.

If you want to call me dim (or suggest a story) then just click on the email link to the top right of the page.

• Bookmark with:
• |
• |
• |
• |
• - What's this?