20 mph limit

[Pingu]

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The 20mph speed limit is expected to be self enforcing...

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LOL 

[Eccentrica Gallumbits]

People of Edinburgh will never be able to get a plumber again. http://www.edinburghnews.scotsman.com/news/transport/20mph-zones-will-drive-out-tradesmen-1-3654779

[ian]

People of Edinburgh will never be able to get a plumber again. http://www.edinburghnews.scotsman.com/news/transport/20mph-zones-will-drive-out-tradesmen-1-3654779

Well, that's some certainly extraordinary logic. I salute the good people of Edinburgh city centre for their efforts to keep those poor tradesmen in business by pretending to have problems with their plumbing, roofs, gardens etc.

[Eccentrica Gallumbits]

Perhaps all tradesmen's vans are set like the bus in Speed so if they drop below 25mph they explode.

[Kim]

As if to emphasise that point, someone just parked a Dirty White Van With Ladders on the pavement outside at speeds in excess of R17

[Cudzoziemiec]

Sounds to me like either the Ed News are recycling plot lines from "reasons to object to congestion charge" without bothering to check they fit, or the tradesmen see an excuse to put up call out charges.

[Regulator]

Perhaps all tradesmen's vans are set like the bus in Speed so if they drop below 25mph they explode.

That would explain why they never turn up when they're supposed to...

[Bledlow]

Is there any point?? <rant>It's never enforced (much like the seatbelt law & mobile phone usage in cars).</rant>

But some people will obey it, so it will become self-enforcing.

Weeellllll . . . . . . I obey 20 mph speed limits, & I've been tooted at a few times by impatient people who thought I should break the limit. I've also been overtaken in a 20 mph zone while driving at 20.

But I've been overtaken in a 30 mph zone while doing over 30 on a bike.

[Cudzoziemiec]

Some people seem to think that 20mph zones are a failure because people are not, all of a sudden, driving at 20mph. But one of their effects is that driving at 40 becomes less acceptable, not least to the police. I think they also signal the start of a change, or at least an attempt to change, road climate and traffic culture, making it easier to introduce other measures later (parking controls, road repurposing, etc).

[Kim]

Agreed.  I'm hoping that they might pave the way for selective permeability, if not more rigorous enforecement.

[Cudzoziemiec]

I see selective permeability as almost here already. But here isn't Birmingham! More rigorous enforcement I think depends on funding and stuff like vote-your-chief-cop.com.

[T42]

It's about the only speed limit I can break on my bike.

[bodach]

  The 20mph speed limit would be unecessary if drivers obeyed the 30mph limit and didn't take it as a target to be reached or exceeded. I drove thro' Linlithgow high street observing the 20 limit yesterday morning with a following driver shaking his head in disgust at my behaviour.

[Mr Larrington]

Some people seem to think that 20mph zones are a failure because people are not, all of a sudden, driving at 20mph. But one of their effects is that driving at 40 becomes less acceptable, not least to the police. I think they also signal the start of a change, or at least an attempt to change, road climate and traffic culture, making it easier to introduce other measures later (parking controls, road repurposing, etc).

Round here the polis are usually doing 50+ anyway.  When they're not parked like fuds outside the chippie.

[sg37409]

  The 20mph speed limit would be unecessary if drivers obeyed the 30mph limit and didn't take it as a target to be reached or exceeded. I drove thro' Linlithgow high street observing the 20 limit yesterday morning with a following driver shaking his head in disgust at my behaviour.

Agreed.
I was going to comment on the postive effect its had on Linlithgow high street.
Nobody does 20 (apart from you ;-) ) , but nobody did 30 when it was a 30.  Reducing the limit did slow the traffic down noticably.
If we really want people to drive at 20, it seems we need a 10 mph speed limit.

[ian]

Whereas in principle they're a good thing and do probably slow the overall speed down, they also fail in two ways (when not used with other measures). Firstly people don't assume an urban nirvana outside their door so kids stay locked in and every still fears the traffic. You can't assume that traffic will be slow. Secondly, a proportion of cars clearly ignore it and do so without sanction. I used to cycle through a 20 mph zone in Bromley and it was pretty horrible because it was a rat-run with single file streets, so some cars would barrel down them at speed as they tried to avoid the lights on the main road (the irony being that I'm sure that was nearly always a quicker route, the rat run only worked if a driver didn't mean another driver coming the other way, at which point the usual complex negotiation for road space would commence via the medium of aggressive beeping). LBC wouldn't countenance blocking the streets with a barrier 'because it would inconvenience residents and access to a local school'. Note the vehicle-focus. Crappy excuse, access for residents would have been straightforward from the two main roads that bordered the area.

[Cudzoziemiec]

Yes, any speed limit, or indeed any road blockage, parking restriction, limited access zone, etc, is only a palliative for the fundamental problem of too many cars. Perhaps even too much traffic.

[Diver300]

https://www.bbc.co.uk/news/uk-wales-63646023
The headline says no significant improvement in safety, but looking a bit deeper, there's no significant reduction in

crashes, casualty rates or average speeds

This reinforces my opinion that speed limits are ignored to such an extent that they are virtually irrelevant without enforcement.

Of course, the irrelevance of speed limits allows councils to post some pointless ones.

[ian]

You don't even have to finish the abstract

Results showed little change in mean traffic speed at year 1 (0.2 mph, 95% CI −0.3 to 2.4, p=0.14) and year 3 post-implementation (0.8, 95% CI −1.5 to 2.5, p=0.17).

So, yeah, unenforced pretend speed limits unsurprisingly don't work.

[Jaded]

You don't even have to finish the abstract

Results showed little change in mean traffic speed at year 1 (0.2 mph, 95% CI −0.3 to 2.4, p=0.14) and year 3 post-implementation (0.8, 95% CI −1.5 to 2.5, p=0.17).

So, yeah, unenforced pretend speed limits unsurprisingly don't work.

You mean like every speed limit that doesn't have yellow gantries at the beginning, middle and end?

Not sure why 20mph is silly when people 'unsurprisingly' ignore 30, 40, 50, 60?

If we are to not put in speed limits where people ignore them then we should have no speed limits.

[fd3]

I viscerally agree with you Jaded, but confronted with the data that shows that the limits make f all difference I now am struggling for the next step.
To me I think that putting in the speed limits can’t hurt, and then we can enforce them at some point.  The story I always bring up at this point is motorway speed limits in Belgium; growing up they were always ignored and not enforced, then one year I came back in the summer from uni and everyone was driving below the limit.  Turns out that it took three months of police enforcing the speed limits for the whole country to change behaviour.

[Jaded]

Motorway driving on Scotland is generally more law abiding than in England.

A few years ago Scotland Police* said they were not going to allow any leeway, so no 10% plus 2 or whatever the accepted 'limit' is in England.

*Not sure if that is their name nowadays, or ever.

[Diver300]

I viscerally agree with you Jaded, but confronted with the data that shows that the limits make f all difference I now am struggling for the next step.
To me I think that putting in the speed limits can’t hurt, and then we can enforce them at some point.  The story I always bring up at this point is motorway speed limits in Belgium; growing up they were always ignored and not enforced, then one year I came back in the summer from uni and everyone was driving below the limit.  Turns out that it took three months of police enforcing the speed limits for the whole country to change behaviour.

I think that the biggest problem with unenforced speed limits is that it encourages a culture of ignoring them, especially when the response to that is to reduce the speed limit that is already ignored.

In my experience enforcement is what makes a difference.

[Kim]

The roll-out made little difference here, but then everyone's favourite police officers made a big fuss about enforcing them, which did seem to have an effect.  It's now reached a state where most drivers ignore them, but at busy times they're forced to drive at 20 behind the few who don't, which makes cycling in traffic a lot more pleasant.

The real problem is on residential roads that don't have a continuous flow of traffic.  The only thing that controls speed is having to squeeze past oncoming vehicles.

[ian]

You don't even have to finish the abstract

Results showed little change in mean traffic speed at year 1 (0.2 mph, 95% CI −0.3 to 2.4, p=0.14) and year 3 post-implementation (0.8, 95% CI −1.5 to 2.5, p=0.17).

So, yeah, unenforced pretend speed limits unsurprisingly don't work.

You mean like every speed limit that doesn't have yellow gantries at the beginning, middle and end?

Not sure why 20mph is silly when people 'unsurprisingly' ignore 30, 40, 50, 60?

If we are to not put in speed limits where people ignore them then we should have no speed limits.

My point was that the study wasn’t measuring the effect of an actual speed limit since everyone was driving the same speed. It was measuring the effect of an advertised speed limit. It seemed ineffective at reducing speed or driver behaviour so, of course, no change in casualties. My take-home is that we enforce these limits and we take speeding seriously. I’m biased having had the benefits of a nice relaxing coma courtesy of a speeding driver, of course.