UKTC Archive

RE: Windshield/Drive-by | Speed Limit

Subject: RE: Windshield/Drive-by | Speed Limit
From: David Evans
Date: Dec 02 2019 06:22:14
<<David, after re-reading your website I am still left asking how do you 

1) It's not reasonable
2) It's not proportionate
3) It's not reasonably practicable>>

Hi Michael

I'm a bit baffled about what you're after here.  You first asked me...

<<Can you please tell us exactly what is reasonable, practical and 

Which is written up in VALID's Tree Risk-Benefit Management Strategies, and 
you seem to be struggling with this*.  If you want to know more, there's 
always Chapter 2 & 3 of the NTSG's Common Sense Risk Management of Trees, 
which expands on it in more detail.  Or Professor David Ball's "Public Safety 
& Risk Assessment".  I'm pretty certain I can't explain it any further than 
what already I've set out.

Now, you appear to be asking why Jeremy's highways stuff isn't?

As for the rest.

<<I have no idea why you propose 5 years, not 4 or 6 or 7 years 2 months.>>

5 Years Active Assessment frequency is a serving suggestion based on a number 
of points.  Not least the 'proportionate' factors that the overall risk from 
tree failure is extremely low.  The "prospects of reducing the risk from tree 
failure below the current level are remote and comparable to finding a 
microscopic needle in a gargantuan haystack" - Professor David Ball (part for 
the risk advisory team to NTSG)

In application, Kent County Council (who were the first local government 
organisation to host VALID training) is one of the main Highways Authorities 
in the UK, and they carry out a 5 yearly assessment.  Birmingham City Council 
is the largest municipality in Europe, and they carry out a 5 yearly 
assessment.  Whilst putting VALID together, when canvassing local 
governments, urban forestry academics, and solicitors representing local 
government in the UK, New Zealand, Australia, and the US, there seems to be a 
general agreement that a 5 year Active Assessment frequency is 'reasonable' 
and 'proportionate'; particularly when it's being topped up by Passive 
Assessment.   Hence, the Tasmanian Government are going to adopt a 5 year 
Active Assessment frequency on their roads.  It's why I'm proposing 5 years 
instead of 7 years 2 months.  Up to now, there's been no benchmark for this.  
I'm suggesting one that seems to be widely agreed.  Have you got a better 

However, it's up to the duty holder to agree a frequency of assessment and 
they can go for whatever they want.  They could even go for your fatuous 7 
years 2 months if they chose.  It's their call.  But if as a profession we 
can get some kind of consistency, then when a legal claim is inevitably made 
we're in a better position to justify this frequency of assessment rather 
than be held hostage by highly questionable expert witness testimony, 
resulting in equally questionable court Judgments.  The court looks to our 
profession to set standards.  It's not the other way around, as some might 

<< In the case of KEW we know the number of visitors per year and the number 
of hours workers have been on the grounds.  We wold know similar numbers for 
many roads and public places, but we don't know for many other places, thus 
how do you determine under VALID your three criteria.>>

I really have no idea what you're asking here.  But it looks like you 
might've been confusing risk management with risk assessment from the get go*.


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