20 mph limits dangerous?
Discussion
I drive around London a lot and need my licence for my business, luckly my Mercedes sprinter cruise control can be set at 20mph, I seem to be he only one that sticks to the ridiculous limits as cars, vans and mopeds are always overtaking me which is surely more dangerous than a 30 mph limit when most people seem to stick to it what does everyone else think?
Your kid runs out into the road. Mr 20mph hits the brakes your kid more than likely lives.
At 30mph your kid is seriously injured or dead. You're still doing about 14 mph at the point of impact as 80% or so of the speed is lost in the last few feet of emergency braking. Physics.
Merc Sprinter you say. In white by chance?
Ultimately its up to your conscience regarding killing a kid, but the limits are set because of the areas high pedestrian numbers including family's, children, wifes, husbands, mums, dad, grandma's etc.
Accelerating up to 30/35 in an urban environment just to stamp on the brakes a few yards down the road seems like wasted effort and stress to me.
At 30mph your kid is seriously injured or dead. You're still doing about 14 mph at the point of impact as 80% or so of the speed is lost in the last few feet of emergency braking. Physics.
Merc Sprinter you say. In white by chance?
Ultimately its up to your conscience regarding killing a kid, but the limits are set because of the areas high pedestrian numbers including family's, children, wifes, husbands, mums, dad, grandma's etc.
Accelerating up to 30/35 in an urban environment just to stamp on the brakes a few yards down the road seems like wasted effort and stress to me.
StuVT said:
Your kid runs out into the road. Mr 20mph hits the brakes your kid more than likely lives.
At 30mph your kid is seriously injured or dead. You're still doing about 14 mph at the point of impact as 80% or so of the speed is lost in the last few feet of emergency braking. Physics.
Mr 0mph can let his kids pay in the road.... ban all vehicles At 30mph your kid is seriously injured or dead. You're still doing about 14 mph at the point of impact as 80% or so of the speed is lost in the last few feet of emergency braking. Physics.
Not sure whether you have the misery of driving round London or not, but these 20mph limits are popping up everywhere, not just on heavily populated narrow roads. Herne Hill is a good example. Massive wide road with huge wide pavements and relatively few pedestrians ... now 20mph. It's not really about safety though, it's about making London as awkward a place as possible to drive around in the hope that you'll hop on to the 'oh so excellent' public transport system or (God forbid) a bike.... not a lot of use if you need to deliver or move gear around, but that doesn't occur to Sadiq and his mates!
Most 20 limits will, in a massive majority of cases, only be signed off by Plod (who are responsible for enforcing it) if the average traffic speed is <24mph, that is one of the key criteria. Another is that they are self-enforcing, which can be speed bumps but is usually just additional signs and roundels on the road.
I regard 20's as doing what 30's did before cars got super-modern, refined and quick. OK, do 25mph in a 20 - it's not the end of the world, you in all likelihood won't get tugged because the Police generally don't enforce 20mph limits, your stopping distance isn't greatly increased, and you can still be aware of everything that's going on. You might even get up to 30. But it's stopping the mentality of "it's a 30, so I can do 37 or 38". Everyone breaks the speed limit on occasion. 20s try to stop people from really taking the piss.
(I once put 20 limits and zones in a City (not London) and the actual effect of changing the number on the lollipop from 30 to 20 didn't slow things down too much.)
https://assets.publishing.service.gov.uk/governmen...
Page 20 onwards gives the guidance - it will have been written with input from Plod, they don't want to make a rod for their own backs and have to go out and enforce a 20 limit.
I regard 20's as doing what 30's did before cars got super-modern, refined and quick. OK, do 25mph in a 20 - it's not the end of the world, you in all likelihood won't get tugged because the Police generally don't enforce 20mph limits, your stopping distance isn't greatly increased, and you can still be aware of everything that's going on. You might even get up to 30. But it's stopping the mentality of "it's a 30, so I can do 37 or 38". Everyone breaks the speed limit on occasion. 20s try to stop people from really taking the piss.
(I once put 20 limits and zones in a City (not London) and the actual effect of changing the number on the lollipop from 30 to 20 didn't slow things down too much.)
https://assets.publishing.service.gov.uk/governmen...
Page 20 onwards gives the guidance - it will have been written with input from Plod, they don't want to make a rod for their own backs and have to go out and enforce a 20 limit.
Edited by OpulentBob on Thursday 4th October 07:15
I live on one of these new 20mph limits. This road runs parallel to the A22 and is used as a diversion when the A22 is closed by all traffic including artics, and is also a bus route with a school in the middle. I have yet to see a bus observe the new limit, at certain times used as a racetrack by Zafira and 4x4 mums in a rush to either drop of or collect their often vile offspring. and the local yoof in their blacked out Corsas love it to scream down at all times.
I can’t see what the point was, other than political - nothing has changed other than a load of 20 repeater signs making the view untidy.
I can’t see what the point was, other than political - nothing has changed other than a load of 20 repeater signs making the view untidy.
The 'think of the children' argument is flawed as it's parental responsibility to make sure that if their children are very young then they are supervised and if they are simply young then they know how to cross the road, entitlement by pedestrians has now reached epidemic proportions with lotd simply not even looking before stepping into the road.
I used to commute in by bicycle (Kent to Zone 1) when they first introduced 20mph zones and I immediately noticed it was more dangerous for someone cycling as lots of cars ignored it yet some cars abided by it but went 15mph which caused road rage, I live in a 30mph borough but the one next to me is a 20mph borough and KSI's per mile driven are a lot higher there.
Busses in London are now fitted with 20mph limiters which means that drivers can't make up time anymore if running late or at night and so now instead drive through red lights and perform other risky maneuvers to stay on schedule.
All buses fitted with ISA remained within the speed limit 97-99% of the time. The few incidences of speeding
occurred on downhill sections, as acceleration was the result of gravity.
The percentage of time spent travelling above the speed limit reduced from a range of 15-19% to 1-3% in 20mph
zones and 0.5-3% to 0-1% in 30mph zones (+/-50km/h).
No adverse effect on behaviour was recorded, despite an expected increase in riskier overtaking by surrounding
traffic. An increase in platooning from vehicles behind the buses was noted which led to a reduction in average
speeds in 20mph zones. A marginal increase in journey times was also reported.
https://etsc.eu/wp-content/uploads/ISA_BusesIntell...
I used to commute in by bicycle (Kent to Zone 1) when they first introduced 20mph zones and I immediately noticed it was more dangerous for someone cycling as lots of cars ignored it yet some cars abided by it but went 15mph which caused road rage, I live in a 30mph borough but the one next to me is a 20mph borough and KSI's per mile driven are a lot higher there.
Busses in London are now fitted with 20mph limiters which means that drivers can't make up time anymore if running late or at night and so now instead drive through red lights and perform other risky maneuvers to stay on schedule.
All buses fitted with ISA remained within the speed limit 97-99% of the time. The few incidences of speeding
occurred on downhill sections, as acceleration was the result of gravity.
The percentage of time spent travelling above the speed limit reduced from a range of 15-19% to 1-3% in 20mph
zones and 0.5-3% to 0-1% in 30mph zones (+/-50km/h).
No adverse effect on behaviour was recorded, despite an expected increase in riskier overtaking by surrounding
traffic. An increase in platooning from vehicles behind the buses was noted which led to a reduction in average
speeds in 20mph zones. A marginal increase in journey times was also reported.
https://etsc.eu/wp-content/uploads/ISA_BusesIntell...
StuVT said:
Your kid runs out into the road. Mr 20mph hits the brakes your kid more than likely lives.
At 30mph your kid is seriously injured or dead. You're still doing about 14 mph at the point of impact as 80% or so of the speed is lost in the last few feet of emergency braking. Physics.
This is the classic argument isn't it..... an engineered situation whereby in both cases the vehicle hits a pedestrian.At 30mph your kid is seriously injured or dead. You're still doing about 14 mph at the point of impact as 80% or so of the speed is lost in the last few feet of emergency braking. Physics.
This line of argument can be extruded to any extreme and for the promotion of any speed limit.
For example, if say the speed limit was 20mph, and you engineered a situation whereby a kid falls from the pavement and is laying in the road, just at the moment a 20mph car passes..... obviously the kid dies as the car runs over. So the argument solution is to reduce to 10mph?
Then for example, if say the speed limit was 10mph, and you engineered a situation where a kid crawls out from behind a parked car (ie. below the bonnet sight level of a driver)....and the car runs over the kid at 10mph...... argument solution....lets try 5mph ?
And so on, to the point that your argument is simply about the movement of vehicles, which is basically their design purpose. Therefore the argument about constantly reducing speed limits is nothing more than an argument to ban vehicles on the road.
Obviously this line of thinking is also an extreme, just as much so for many of the engineered accident cases that exist for constantly placing the blame on speed.
untakenname said:
The 'think of the children' argument is flawed as it's parental responsibility to make sure that if their children are very young then they are supervised and if they are simply young then they know how to cross the road, entitlement by pedestrians has now reached epidemic proportions with lotd simply not even looking before stepping into the road.
Yes and no (imo)...As a kid (in the 80's) I remember there was a lot of emphasis on road safety (green cross code, tufty, etc) but I remember at least 2 kids were killed on the roads in our village when I was at school. Both would have been early teens, so you'd think old enough to know how to cross the road. One ran out from behind the school bus, the other I think just misjudged the gap in traffic. In both cases the car wasn't speeding, but if they'd been doing 20 instead of 30 you never know the outcome might have been different.
I remember reading an article a few years ago and think it said something about how your spatial awareness and perception of speed isn't fully developed until your late teens or even early 20's?
But back to the main point, I don't think 20mph limits are dangerous per se, but I do think the overuse of them is. Used properly and in the right areas people are more likely to pay attention, but blanket 20's everywhere will just piss people off and they'll just ignore them all the time.
Atomic12C said:
StuVT said:
Your kid runs out into the road. Mr 20mph hits the brakes your kid more than likely lives.
At 30mph your kid is seriously injured or dead. You're still doing about 14 mph at the point of impact as 80% or so of the speed is lost in the last few feet of emergency braking. Physics.
This is the classic argument isn't it..... an engineered situation whereby in both cases the vehicle hits a pedestrian.At 30mph your kid is seriously injured or dead. You're still doing about 14 mph at the point of impact as 80% or so of the speed is lost in the last few feet of emergency braking. Physics.
This line of argument can be extruded to any extreme and for the promotion of any speed limit.
We have a blanket 20 mph in our town. Like the 30 mph which was in place before there's no funding for speed enforcement (there was funding for all new signs and for trying to recruit volunteer speed monitors).
Habitual speeders continue to break the speed limit.
According to minutes from a local council meeting the 20 mph isn't even legally enforceable (due to access via unadopted roads or similar).
We moved from our last home in part due to being on a busy 30 mph road with people routinely breaking the limit - often by a significant margin. Again there was no funding for enforcement.
I too have little confidence in them being effective.
Habitual speeders continue to break the speed limit.
According to minutes from a local council meeting the 20 mph isn't even legally enforceable (due to access via unadopted roads or similar).
We moved from our last home in part due to being on a busy 30 mph road with people routinely breaking the limit - often by a significant margin. Again there was no funding for enforcement.
I too have little confidence in them being effective.
Zetec-S said:
A kid running out into the road isn't really an engineered situation, ....
Ah, but it is if your also include the vehicle that is always going to hit.The engineered case is that 'A' must make contact with 'B' given any travelling speed.
That is the pre-set condition which the argument is based up on.
ie.
'A' traveling at speed 30mph hits 'B' who is in the road.
'A travelling at speed 20mph hits 'B' who is in the road.
etc.
The premise of the argument doesn't take a specific case of reality, ..... if it did, then if for example if a kid runs in to the road and was hit by a car at 20mph, was run over and died. It could be said that the same car in the same situation would have passed the kid if travelling at 40mph a few seconds prior to the kid running out in to the road. the result being no contact and no death.
However, arguments on the basis of cars at speed 'x' hitting pedestrians in comparison to cars at speed 'y' hitting pedestrians are always an engineered situation (for the purposes of the argument).
In cases of 20mph speed zones, I would much prefer them to be scrapped in favour of 30mph with more of a police focus on things like dangerous driving, mobile phone use etc. Together with those common sense adverts that we used to see on TV a while back - focussing on parents educating children that roads are for vehicles and the dangers of being next to a road.
When I was young I remember from a very early age a clear understanding of dangers near a road, my parents were good at installing common sense. This is maybe something that has eroded over time in the UK as the culture of always pointing the finger of blame to a 3rd party has sadly become the norm.
Atomic12C said:
This is the classic argument isn't it..... an engineered situation whereby in both cases the vehicle hits a pedestrian.
This line of argument can be extruded to any extreme and for the promotion of any speed limit.
For example, if say the speed limit was 20mph, and you engineered a situation whereby a kid falls from the pavement and is laying in the road, just at the moment a 20mph car passes..... obviously the kid dies as the car runs over. So the argument solution is to reduce to 10mph?
Then for example, if say the speed limit was 10mph, and you engineered a situation where a kid crawls out from behind a parked car (ie. below the bonnet sight level of a driver)....and the car runs over the kid at 10mph...... argument solution....lets try 5mph ?
And so on, to the point that your argument is simply about the movement of vehicles, which is basically their design purpose. Therefore the argument about constantly reducing speed limits is nothing more than an argument to ban vehicles on the road.
Obviously this line of thinking is also an extreme, just as much so for many of the engineered accident cases that exist for constantly placing the blame on speed.
Agreed, if the speed limit was 30 then the car would have already passed the incident and all the kids would be safe!This line of argument can be extruded to any extreme and for the promotion of any speed limit.
For example, if say the speed limit was 20mph, and you engineered a situation whereby a kid falls from the pavement and is laying in the road, just at the moment a 20mph car passes..... obviously the kid dies as the car runs over. So the argument solution is to reduce to 10mph?
Then for example, if say the speed limit was 10mph, and you engineered a situation where a kid crawls out from behind a parked car (ie. below the bonnet sight level of a driver)....and the car runs over the kid at 10mph...... argument solution....lets try 5mph ?
And so on, to the point that your argument is simply about the movement of vehicles, which is basically their design purpose. Therefore the argument about constantly reducing speed limits is nothing more than an argument to ban vehicles on the road.
Obviously this line of thinking is also an extreme, just as much so for many of the engineered accident cases that exist for constantly placing the blame on speed.
Piston heads, Speed Saves!
Funky Squirrel said:
Atomic12C said:
This is the classic argument isn't it..... an engineered situation whereby in both cases the vehicle hits a pedestrian.
This line of argument can be extruded to any extreme and for the promotion of any speed limit.
For example, if say the speed limit was 20mph, and you engineered a situation whereby a kid falls from the pavement and is laying in the road, just at the moment a 20mph car passes..... obviously the kid dies as the car runs over. So the argument solution is to reduce to 10mph?
Then for example, if say the speed limit was 10mph, and you engineered a situation where a kid crawls out from behind a parked car (ie. below the bonnet sight level of a driver)....and the car runs over the kid at 10mph...... argument solution....lets try 5mph ?
And so on, to the point that your argument is simply about the movement of vehicles, which is basically their design purpose. Therefore the argument about constantly reducing speed limits is nothing more than an argument to ban vehicles on the road.
Obviously this line of thinking is also an extreme, just as much so for many of the engineered accident cases that exist for constantly placing the blame on speed.
Agreed, if the speed limit was 30 then the car would have already passed the incident and all the kids would be safe!This line of argument can be extruded to any extreme and for the promotion of any speed limit.
For example, if say the speed limit was 20mph, and you engineered a situation whereby a kid falls from the pavement and is laying in the road, just at the moment a 20mph car passes..... obviously the kid dies as the car runs over. So the argument solution is to reduce to 10mph?
Then for example, if say the speed limit was 10mph, and you engineered a situation where a kid crawls out from behind a parked car (ie. below the bonnet sight level of a driver)....and the car runs over the kid at 10mph...... argument solution....lets try 5mph ?
And so on, to the point that your argument is simply about the movement of vehicles, which is basically their design purpose. Therefore the argument about constantly reducing speed limits is nothing more than an argument to ban vehicles on the road.
Obviously this line of thinking is also an extreme, just as much so for many of the engineered accident cases that exist for constantly placing the blame on speed.
Piston heads, Speed Saves!
StuVT said:
Your kid runs out into the road. Mr 20mph hits the brakes your kid more than likely lives.
At 30mph your kid is seriously injured or dead. You're still doing about 14 mph at the point of impact as 80% or so of the speed is lost in the last few feet of emergency braking. Physics.
Merc Sprinter you say. In white by chance?
Ultimately its up to your conscience regarding killing a kid, but the limits are set because of the areas high pedestrian numbers including family's, children, wifes, husbands, mums, dad, grandma's etc.
Accelerating up to 30/35 in an urban environment just to stamp on the brakes a few yards down the road seems like wasted effort and stress to me.
Didn’t take long for think of the poor deceased children I see. Like I said, I’d like to see some stats showing if 20mph limits have had any effect on the injury rate on those roads. At 30mph your kid is seriously injured or dead. You're still doing about 14 mph at the point of impact as 80% or so of the speed is lost in the last few feet of emergency braking. Physics.
Merc Sprinter you say. In white by chance?
Ultimately its up to your conscience regarding killing a kid, but the limits are set because of the areas high pedestrian numbers including family's, children, wifes, husbands, mums, dad, grandma's etc.
Accelerating up to 30/35 in an urban environment just to stamp on the brakes a few yards down the road seems like wasted effort and stress to me.
BTW, your kids bicycle is likeky the most dangerous thing they own, irrespective of where it is used. You better stop using it. Have you taken your kids bicycles away?
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