Author Topic: Times article on new road safety strategy  (Read 2333 times)

rogerzilla

  • When n+1 gets out of hand
Times article on new road safety strategy
« on: 16 May, 2008, 09:14:35 am »
http://business.timesonline.co.uk/tol/business/industry_sectors/transport/article3941769.ece

Hopefully h*lm*ts aren't part of it, but the goverment are fully aware of the problems in trying to bring in a MHL, given low existing h*lm*t wearing rates.

I like this bit:

Quote
Cameras that detect a vehicle’s average speed will be used instead of road humps to enforce the limit in some of the new 20mph zones.

because I hate speed cushions and humps, although I suppose cameras don't catch the unregistered or false-plated vehicles.

The comments include those from the usual "stay on the pavements and keep out of my way" retards.
Hard work sometimes pays off in the end, but laziness ALWAYS pays off NOW.

Re: Times article on new road safety strategy
« Reply #1 on: 16 May, 2008, 09:20:59 am »
Roger, I agree with you about road humps. We in the UK seem to think of everything in terms of technological fixes - so we end up with a cluttered streetscape of barriers, speed humps, buildouts and chicanes. Buildouts are a bugbear of mine - I read a quote somewhere else to the effect that pinch points use the soft, squishy bodies of cyclists as mobile speed humps. Why do we put up with things like that which are actively dangerous to cyclists just to control the anti-social speeding of the few?

IMHO, we should be looking at more Home Zones and psychological traffic calming - people would modulate their speed if the visual cues on the road saud "This is a shared space. People live and play here". Instead we have streets with "safety railings" to cage those pesky pedestrians and create highways to zoom along.

Re: Times article on new road safety strategy
« Reply #2 on: 16 May, 2008, 09:26:03 am »
Prize eejit comment:
"don't understand. One minute we're complaining of road congestion slowing the traffic down - making it safer. Then we introduce bigger faster environmentally unfriendly roads to speed the traffic up. Then we want to slow it down again !!"

Errr.... in central London average traffic speeds are 12mph. I know this - it takes me around one hour to reach the start of the M4. A distance of 14 miles.
And exactly what is the variable speed limit on the M25? Errrrr... it acts to slow down the traffic in times of congestion, which results in overall more traffic passing along the road.

If I'm not wrong (need a reference) it has been proved that slowing traffic on urban streets in fact raises overall traffic throughput. Am I right here?








rogerzilla

  • When n+1 gets out of hand
Re: Times article on new road safety strategy
« Reply #3 on: 16 May, 2008, 09:39:34 am »
If I'm not wrong (need a reference) it has been proved that slowing traffic on urban streets in fact raises overall traffic throughput. Am I right here?

On main roads a limit of 50mph rather than 70mph (or, more realistically, 80mph where unenforced by cameras) allows cars to travel closer together, increasing the number of vehicles per mile of road space, and this seems to outweigh the slower speed of travel.  It also reduces the "concertina effect" where you can be doing 70mph one minute and parked the next, familiar to anyone who has used the M4 around reading at peak times.  In slower urban areas I'm not sure whether the same applies.
Hard work sometimes pays off in the end, but laziness ALWAYS pays off NOW.

Re: Times article on new road safety strategy
« Reply #4 on: 16 May, 2008, 09:51:35 am »
A drop in speed limits alone would make some difference.  People do tend to drive differently in traffic-calmed areas. 

Just as long as it isn't accompanied by speed bumps, which are actively dangerous.  I felt moved to write to the council about the ones in my street, as they're wide enough apart for a tranny van to straddle them at speed, and as people ignore the yellow lines, I've nearly been in a head-on collision a couple of times.

The council's response?  No reply, and extra speed bumps for a radius of about a quarter mile.

rogerzilla

  • When n+1 gets out of hand
Re: Times article on new road safety strategy
« Reply #5 on: 16 May, 2008, 09:55:14 am »
I felt moved to write to the council about the ones in my street, as they're wide enough apart for a tranny van to straddle them at speed,
Or big 4x4s, apparently a reason some people buy them in urban areas.
Hard work sometimes pays off in the end, but laziness ALWAYS pays off NOW.

Furious

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Re: Times article on new road safety strategy
« Reply #6 on: 16 May, 2008, 10:07:47 am »
The comments are funny.  ;D
It's a bit like reading Viz Top Tips...
Quote
"This number is based on the idea that using the road network should be no more than twice as dangerous as everyday activities such as DIY."
Can't we make DIY more dangerous instead.
Tom, London,
Quote
If fewer traffic police results in less accidents reported, surely the answer is to get rid of all the traffic police
Aarnie, Bedlam,
Wer sein Fahrrad liebt, der schiebt.
He who loves his bike, will push it.

Re: Times article on new road safety strategy
« Reply #7 on: 16 May, 2008, 10:21:50 am »
If I'm not wrong (need a reference) it has been proved that slowing traffic on urban streets in fact raises overall traffic throughput. Am I right here?

On main roads a limit of 50mph rather than 70mph (or, more realistically, 80mph where unenforced by cameras) allows cars to travel closer together, increasing the number of vehicles per mile of road space, and this seems to outweigh the slower speed of travel.  It also reduces the "concertina effect" where you can be doing 70mph one minute and parked the next, familiar to anyone who has used the M4 around reading at peak times.  In slower urban areas I'm not sure whether the same applies.

If you actually think of a "unit" as being a car plus it's stopping distance, then you can fit x units on a mile of road, providing a throughput of y units per hour at z mph.

Remember: The stopping distance quadruples every time the speed doubles. 

Now I accept that not all drivers do honour the stopping distance, but in town at 10mph they do have a much smaller one than on a motorway at 80mph (in general).  A bump at 10mph due to no stopping distance causes little long lasting blockage, whereas a bump at 80mph can close three lanes for a few hours.

So, back to the original formula, if you compute all iterations of z (the speed) then you find that as the z decreases x increases due to the smaller stopping distance.  Graphing y clearly shows that from zero mph the faster you go the more vehicles can travel through a section of road, until about 15 or 16 mph, at which point the volume starts decreasing again.

To get the maximum number of people from A to B on a motorway they all need to move at that speed (as seen during the bank holiday rush).  This also has the advantages that should a bump occur it won't be long before it's cleared.