JNugent wrote:

> Some satnavs do display road speed. Some don't.
>
> But there is a website (maybe more than one) you can go to (eg, on a mobile
> phone) which tells you how fast you are travelling. Put the phone on a cradle
> and in effect, it's a speedometer. Useful, among other things, for checking the
> accuracy of the car's speedo.
mine is +1mph over a wide range, also the roadside blinking speed displays agree.

In message <0sfijixa56.ln2@threeformcow.myzen.co.uk>, at 13:13:20 on
Mon, 25 Apr 2022, #Paul <news20k.noreply@threeformcow.myzen.co.uk>
remarked:
>Roland Perry <roland@perry.co.uk> wrote:
>> In message <t44gt6$7qj$1@dont-email.me>, at 22:53:42 on Sun, 24 Apr
>> 2022, Steve Walker <steve@walker-family.me.uk> remarked:
>>>On 23/04/2022 19:34, #Paul wrote:
>>>> Steve Walker <steve@walker-family.me.uk> wrote:
>>
>>>>> Yes. Manchester put one in place and just as they finished, the research
>>>>> came back that showed that they *increased* accidents. They refuse to
>>>>> remove the 20 limits, as they "can't afford it". Personally I'd
>>>>> surcharge the people who authorised the implementation in the first
>>>>> place, without the evidence to back it up, and use that money to
>>>>>remove it.
>>
>>>> Surely even if there were "more accidents", it may be that given the
>>>> presumably lower speeds involved, the amount or severity of any
>>>> injuries sustained -- or the damaged caused -- may have been lesser.
>>>> So I'm not sure that "number of accidents" is the correct criteria.
>>>
>>>The figures quoted just as the Manchester scheme was completed showed
>>>that the death rate was higher.
>>
>> How much of that was pedestrians taking greater risk because the traffic
>> was flowing more slowly (and quite likely more bunched together)?
>
>It would be an interesting thing to unpack, I think. You could easily
>propose quite a lot of reasons why (or why not) this might have happened
>in spite of (or because of) the changes. Perhaps because of pedestrian
>or driver behaviour - and maybe because of changes in outlier behaviour
>rather than average behaviour. Or maybe even some background reason not
>obviously related to the speed limit.
>
>You might, for example, imagine that drivers mostly ignored the new
>limits, and only slowed down by an average of less than 1mph, but
>pedestrians still felt safer and crossed more assertively, leading
>to more relatively more accidents against a background of (faster)
>decreasing accident rates elsewhere. If so, would the 20mph scheme
>be the thing that was to blame?

Also, when driving in a London borough that had fairly recently
introduced a blanket 20mph policy I was alarmed when driving early one
Sunday morning at 20.0mph how many other vehicles zoomed past me on the
inside, the outside, but probably not both at the same time.

Many of those overtaking on the inside were also infringing bus/taxi
lanes to do so.
--
Roland Perry