DRL Government Reading

[Efbe]

was looking through the government statistics website for something totally unrelated when I found this.

Thought it was fairly interesting if you have 15 mins to read through it, so here's the link; http://webarchive.nationalarchives.gov.uk/+/http:/...


The summary basically being:

GVMT said:

although an accident reduction potential exists, it is not possible to
say with certainty whether the benefits of implementing DRL would outweigh the costs.

So in essence there is a very small chance DRLs could help safety, however the claims being put forward are all grossly exaggerated.
And the cost-benefit of introducing DRLs is not high enough.

Just interesting how i've heard nothing from this point of view from either the government or media. From what information I have received had thought that DRLs would dramatically help road safety,it would appear not.

[saaby93]

lol where have you been
In the US many states found that DRLs made other road users relatively less visible
i.e. vulnerable road users pedestrians, cyclists, prams, cows anything without lights
Just the group you wouldnt want the stats to increase

[Yodafone]

DRL may help being more visible, but with them being so bright, people may not realise they have no headlights on.

I found this out tonight when following a DS3 who did not realise she had no lights on when I pulled up next to her as dash board lights come on when engine is running so she thought she had lights on as the DRL were so bright.

[Number 5]

DRL's a.k.a TW@ Lights.

[to3m]

saaby93 said:

lol where have you been
In the US many states found that DRLs made other road users relatively less visible
i.e. vulnerable road users pedestrians, cyclists, prams, cows anything without lights
Just the group you wouldnt want the stats to increase

This has certainly been my experience, just going by relative visibility of things roughly in the path of DRLs. (Though admittedly -- and fortunately -- I've yet to have this theory tested in anger.) This seems particularly true for the high-intensity DRLs that are more like tightly-focussed full beams or fog lights. Makes sense, because the eyes tend to adjust their dynamic range according to the brightest thing visible, even if it's not directly in the line of sight.

That said, despite my general dislike of DRLs, I've found they can help with visibility of oncoming vehicles when you're driving towards the sun. That's sometimes helpful, particularly around this time of year, what with the sun being low in the sky -- though I've also noticed that (regardless of time of year) oncoming cars DO tend to drive on the other side of the road. And I'm pretty sure that side lights or (non-high-intensity) dipped lights, in conjunction with a bit of attention, would do just as well.

[Efbe]

well you guys think the same way as me, I hate them with a vengeance.

but I had assumed statistics would show us how they "will save the world" but it would appear that even the governments own research says not

[briers]

Number 5 said:

DRL's a.k.a TW@ Lights.

My "tt" lights will get re-activated soon when the days start getting grey. No reason for them to be on in the summer.

[snoopstah]

Efbe said:

The summary basically being:

GVMT said:

although an accident reduction potential exists, it is not possible to
say with certainty whether the benefits of implementing DRL would outweigh the costs.

So in essence there is a very small chance DRLs could help safety, however the claims being put forward are all grossly exaggerated.

Erm, that's an interesting summary of the document, but a little biased to your point of view I think...

GVMT said:

Although it is possible to be critical of several specific aspects of the
work very substantial evidence has been presented that the introduction of DRL would result in a net
casualty reduction effect. However, there appears to be greater scientific uncertainty concerning the
size of the expected effect. Some of the parameters in the statistical analysis were not found to be
statistically significant and should, therefore, be treated with some caution. In particular, the evidence
for assuming a 15% reduction in fatal accidents is weak and it was considered that it would be more
technically defensible to assume that a mean effect of between 3.9% and 5,9% (depending on which
biases and assumptions are considered) applied to accidents of all injury severities and that there
would be no effect on damage only accidents.

GVMT said:

There is substantial evidence that the mandatory use of DRL would provide a net accident reduction. However, the evidence concerning the magnitude of the effect and particularly the relationship with accident severity is considerably weaker.

Efbe said:

...but it would appear that even the governments own research says not

What research? The entire paper is an analysis of research conducted by other groups, and the reason that the report is uncertain is due to the questionable quality of the research. The research available suggested a 15% reduction in fatal accidents, whereas the analysis suggests that this figure may be closer to 3.9-5.9%. As stated several times, there is clear evidence that a reduction in fatal accidents will occur, it's simply the size of that reduction which is unclear.

Efbe said:

And the cost-benefit of introducing DRLs is not high enough.

The cost-benefit analysis is based on two 21w incandescent bulbs used for dedicated DRLs, and 160w of general power usage if existing cars were modified to use dipped beam lights as DRLs. As most modern cars that have DRLs do so using LEDs which probably consume in the region of 6w in total, and there are no plans (that I'm aware of) to convert existing vehicles to use DRLs, I think the cost-benefit analysis is no longer relevant today.

Edited by snoopstah on Saturday 30th October 00:06