Joanna Greensmith

Ya qweilhie ar ran
tlywodraeth Cymru

Working on behalf of the
Welsh Government

Asiant Gefnffyrdd De Cymru
South Wales Trunk Road Agent

Traffic Management Advisor
Gwent Police

Police Headquarters
Croesycciliog

CWMBRAN NP44 2X]

Dear Sir

RE: A465 LLANGUA,

1 refer to your letter dated 13 February 2014 regarding the fatal coilision which
occurred on the 10 February 2014 near Liangua and in particular the request for
details in relation to winter maintenance treatment undertaken prior to the collision.

Tn response to your request J haye outlined details as follows:

i, Date and times any road surface treatment may have been applied in relation
lo the surface conditions prior to the reported collision.

Presaiting was instructed on Sunday 9 February 2014 commencing at
L700hs at a spread rate of 20g/sqin. the record of instruction to Parinership
Service Providers is attached with route highlighted in yellow.

2. What records are heid io determine that these works took place together with
the level of substance apptied?

Following the instruction South East Partnership returned a_ Daily
Operational Report on if Februasy 2014 indicating treatment undertaken
(attached with route highlighted in yellow).

gen ang Read : Service - ae Wales Trank Read Agent
Pee y Es . Pennaeth Gwasanaeth - Asiant Cefnffyrdd Be Cyrara
3 Come i Unit 12, tfamdarey House, The Courtyard, Uandarcy, Neath SAIG bt}
‘_——— me E-mail: enqnizics@sauthwales-ra.govek

Wracessees®® Tel: 01792 325960, Fax: 0F792 325802
. wew suuthwates-la.govek
an0ETE

What carriageway surface temperature equipment is availabic to you near this
collision site, and what records of temperature were given ducing the night
prior to this collision?

SWTRA obtain a route based forecasting service provided by the Welsh
Government’s specialist ‘all Wales’ forecast provider, McteoGroup, whe
consider a munber of factors and use various sources of data to produce their
weather forecast models.

This witl include data from roadside weather sensors which record
information such as road surface temperature and air temperature. One of
these sensors is located on the A465 at Llangua.

A text based forecast for the 24 hours ahead is provided by 1300hrs each day
and inchides a colow coded graphical representation of the predicted road
surface temperatures acrass the network, a tabulated route schedule that
indicates those routes likely to require treatment including iminimun road
surface temperatives and worst hazard.

The forecast information provided on the 9 February 2014 indicated a
minimum road surface temperature of +0.6 C on the A465.

What factors you would use to determine the works necessary on a highway (o
reduce the risks of ice forming on the carriageway?

Decisions in relation to presalting action requirements are based on forecast
information provided hy MeteoGroup and are made in accordance with the
guidance contained within the decixion guide and treatment matrices provided
in the SWTRA Adverse Weather Plan (2013/14) in accordance with
WOTRMM Part 5 Adverse Weather (62/07/12).

in consideration of the forecast provided on 9 February 2014 a decision was
made io undertake presalting on the A465 at the time and rate of spread
instructed in accordance with the decision guide and treatment matrices.

A copy of the Decision Matrix Guide and Treatment Matrix Guide is attached.
Are the surfaces determined by a risk assessment or other recognised advice?

The road surface material is considered within the WGTRMM Part 5 Adverse
Weather (02/07/12) guidance in so far as poraus or open textured asphalts
are ireated at a higher spread rate ihan other read surface types.
Purthermore where there are known areas of water seepage onio the
carriageway this is aiso treated ai a higher spread rate. This location was not
a known seepage area,

How does the substance used on the carriageway react with the surface
conditions,

to prevent the formation of ice or frost or to melt existing snow, salt musi
first form a brine solution (dissolution). Therefore, after spreading the salt,
there is a time lag before it becomes effective. The length of the tine required
is dependent upon a number of factors (e.g. the size af the salt grains,
availability of moisture, humidity and vehicle traffic runing on treated
surfaces). Treatment times are considered to allow, where practicable, the
required time for ihis dissolution to take place in order to increase the
effectiveness of the treatment.

What visual evidence can be expected io be seen for persons viewing the
carriageway surface?

Visual evidence is dependant on the rate of spread undertaken and the

prevailing road conditions. During the time lag before the sait enters in to
solution, the salt grains are subject to the effects af wind and traffic whereby
evidence of sali inay be more prevalent in the channels and non trafficked
areas, such as lay-bys, rather than on the main carriageway running lanes
where salt has formed a brine solution due partly to vehicle traffic on treated
surfaces.

I trust that this information answers your enquiry however if you require further
details please do not hesitale to contact me.

Head of South Wales Trunk Road Agent

Encs

SOUTH WALES TRUNK ROAD AGENT

Asiant Cefnftyrdd De Cymru Fv) 2 eae oa

2 ‘Warking on behalf af the
Unit 12, Liandarcy House, Weish Government
The Courtyard,
Llandarcy, Neath. SA10 SEJ Fors, NMF/033

Created on: 13/1212

Scattered showers and bright speits this afternoon. The odd squally hail shower possible with sleet

or wet snow failing above 350m. The showers wili become isclated this evening as clear spells develop
but then more widespread showers will spread iin from the north-west after late evening, again wintry
on high ground, reaching many places by 02-03h. RSTs below zero for a time, exact timing variable
from place ta place - low confidence especially on zero crossing times. Clearer later in the night.
Occasional showers tomorrow morning, wintry or on hits,

Minimum Ait Temperature Minimum RST
-1.5°C

, Route Description... : ‘1 Spread |. Star Time Service Provider
an tgimn?y
M4, SSC ta JZ5 Ne Action
M48, A466, A48 No Action
bad, 124 8. 29, AABN No Action
1 AAO, Aa AAAS atip Fords ™

AAD, Ad4D
South East
AADA2 Watos

AAS, ASO Partnership

No. Action |
Ne Action -

No Action ye South Central
Wates
[Seseon | ne Partneretip

No Action
an on NPTCBC
Ne Action nia

SOUTH WALES TRUNK ROAD AGENT |

Asiant Cefnffyrdd De Cymru < a ewoihio oe ca
‘Working on behalf of the
Unit 12, Llandarcy House, Welsh Government
The Courtyard, "
Llandarcy, Neath. SA40 6EJ Form: NMF/033

— Creaied on: 13/f2M2 ~_Page 2 of2

‘South West
Waies

Partnership

‘Templeton +
Teanprefon 2

Delay treatment if raining

haonod by Ce
Date & Time: 09/02/14 at 13.15 — at 13.45

PR

South Wales Trunk Road Agent Yagwettho arian
Asiant Cefnffyrd@ De Cymru Y% Lipwadraeth Oynoru 6 |
‘Working on behall of the
Unit 12, Liandarcy House, Welsh Government a)
The Courtyard, Form: NMF/056 |_ Edition: 61

___ Llandarey, Neath, SA10 6EJ

Created on: 8" Nov. 2012

To: South Wales Traffic Management Gentre {SWTRA)
Fax. 01792 325805

. DAILY OPERATIONAL REPORT for SWTRA
: SL SRT FERRTaR undertaken bt

CN51 FBA

CN5?7 HGU

CN6é1 DDL

YJ60 BXH
> 46:45 | 18:30

Please note that these salting records are ‘er a 2 24he period from ¢ 42:00pm on the date of ~
action.

eZ
Edition: 0!
_[. Page 2of I

South Wales Trunk Road Agent Yaqnahioarme
Asiant Cefnffyrdd De Cymru ¥ Ke Cywodeneh pare
Working ea dehall of the
Unit 12, Llandarcy House, ‘welsh Goverment
The Courtyard, Form: NMF/0S6

Liandarcy, Neath. SA10 6E3 Created on: 8 Nov. 2012

Aclveise Yeather Phan 2013-14

Decision Matrix Guide

Predicted Road Conditions

Road Surface «ane Wet
Temparature . Precipitation atc. Wet Patches
No rain
May fall below
wee No hoar frost fall before No aclion likely,
eee ee Ne rain Salt (See note monitor weaiher
No hoar frost before A) (See note A}
frost
No fo

Expected rain ‘
BEFORE freezing _| Salt afler rain stops
Expected rain Salt before frost and after rain stops
Expected to fall DURING freezing (See note C}
below #1°C Possible rain Mon} thar
Possibla hoar frost | Sail before frost onitor weal
conditions :
Expected snow Sait before snow fall :
a: Salt before rainfail (See role C} i
Freezing rain Durng rain sf Salt during rainfall (See note ©
After rain Sak after rainfall (Sae note C}

A Particular attention should be given to any possibility of water running
across carrlageways and such locations should be monitored and treated
as required.

B When a weather warning contains reference to expected hoar frost
considerable deposits of frost are Iikely ta occur and close moniforing will
be required. Particular aftention should be given io the timing of
precautionary treatments due io the possibility that salt deposited on a dry
road may be dispersed before it can become effective.

© Under these circumstances rain will freeze on contact with running
surfaces and full pre-treatment should be provided even on dry roads. This
is a most serious condition and should be monitored closely and
continuously throughout the danger periad.

NiNelwork ManagemeatiNctwork Contral Con Advena: 34
Weather - WMS LI-WATTS WME 13,7 Severe Weather

PlantWorking Copy'SWTRA Adverse Weather Pian 13-14

fiext onty}.doc

Adverse Wealher Plan 2013-14

Treaiment Matrix Guide
{in accordance with WGTRMM 2012 Part:5.8 Appilcation of Saly

‘Troatmant Matrix (2012-2013) ~

I
Weather Conditions Alr Dry Salfing | Pre-Weited |
Road Surface Conditions Temp (gin?) Salting !
Road Surface Tamperature(RST} ighn?} i
|_{see Note 1) |
(MARGINAL CONDITIONS} i
Frest or forecast frast, RST ator 10 40 :
above -2°C and dry or damp road
conditions. (Porous / open textured {12} {12}
surfacing, see Note 4). a i
Frost ér forecast frost, RST at or H
above -2°C and wet road conditions 40 42 i
{see Note 3 if wet and lightly See Note 2 :
trafficked}. (Poraus / open textured 45) Below i
surfacing, see Note 4}. { H
a = i) a ee i
Frost or forecast frost, RST balow !
-2°C and above -5°C and dry ar 15 15 49 No
damp road conditions (sea Note 3 if i
daimp and lightly trafficked). {20} (203 (15)
{Porous / open lexturad surfacing, H
see Note 4}. nue i
Frost or forecast frost, RST below
2°C and above -5°C and wet road 20 20 46 No
conditions {see Note 3 if lightly - See Note 2
trafficked). (Porous / open textured 45) Below (20) i
surfacing, sea Nate 4}. {25}
Frosl or forscasi frost, RST at or
betow -5°C and above -10°C and 20 20 No |
dry or damp road condillons (see
Note 3 if damp and lightly {25) (25) :
baificked}. (Poraus / open textured i
surfacing, see Note 4). ee es !
Frost or forecast frost, RST at or i
below -8°C and above -10°C and 2x18 X45 H
wel road conditions (existing or Sea Note 2 |
anticipated) (see Note 3 if lightly % on. :
trafficked). (Porous / opan texlured (2x 20) etow
surfacing or particularly low 2420
temperatures at iawer end of ¢ J
tamperature band, see Note 4}. ee
Light snow forecast (<tOmm). 10-20 18-20 See
a . ___1_ Note 2 Below
Modium/heavy snow or freezing 2x20 Sea Note 2
tain forecast. _j__ Below
Freezing rain failing. 20 See Note 2
(successive) Below _
After freezing rain. 20
(successive se ete 2
as required)
Ice formed {minor accumulations}. above 29 See Note 2
SC _— Below
NaANetwork ManngementiNetwork Contre] CentrclAdverst: 35 ;

Weather « WM\1314-WMI3SVWM 13,7 Seve Weather i
PlantWarking Copy SWIRA Adverse Weather Pisn 13-t4 i
(text only).doc i

Adverse Weather Plan 2013-14

Sf

° ator
low farmed. below L 2x26 » | Sy Sep Mote 2 il 2x15 = No
Treatment Matrix (2042-2073) “pantie
_____ Treatment _.
Weather Conditions Air Ory Saiting Pre-Wetted Pre-Coated § Ploughing
Road Surface Conditlons Temp fat’) Salting Salting
Road Surface Temperature(RST) igh’) (gim?}
a . sae Note 1) . _
Snow covering exceading 30mm. 40-20 See Nole 2 10-45 Yo
. _ __| (successive) | Below —|_ {successive} =
Hard packed snow/ice. above 20 See Note 2 a) No
a : [8c (successive) | Below {successive}
ator
. Saltfabrasive See Note 2 Saltfabrasiva
Hard packed snow/ice. re (succes sive} | Below (successive) No

Rates of ‘spread for precautionary treatments mal iy be adjus fed k to fake account of residual salt or surface
moisture. Refer to mare detailed Advice and Guidance Notes.

JF the indicated spread rate can not be accurately applied due to limitations of the equipment or
calibration difficulties, the next higher spread rate shauid be used. (Fer example: when indicated t2g/m*

use 45gin"}.

Equipment shail be calibrated and adjusted fo ensure that the required spread rates throughout the
sailing route {with varying loads} does not falt below the piininuun rate specified, this is particularly
important for the lower spread rates indicated.

Where double treaiment Is necessary the initial first treatment shall be af the highest spread reate
possible within the fimitations of the spreader for the route length. For example 2xt5g/m’ applied as
4420 gfii® + Ix10 gin’.

_—_t

Notes

4) Spread rates for pre-wetted sait |s the combined weight of dry rock sait and brine
combined at 70:30 proportion by weight respectively. Please see Guidance /

Advice regarding the addition of Agricultural by Praducts (ABP’s} within the brine
10% by volume maximum) cr use of pre-coated salt (3% by welghtof salt).
When ice has formed or snow is lying, dry or pre-coated salting is the preferred
freatment unless the road Is closed to lraific whan pre-wetted salting may he used.
Pre-weted and pre-coated salting !s a more effective treatment in advance of such
conditions. Pre-coated and dry salting should be undertaken when roads are wet

from recent or anticipated pracipiiation. .
3) Treaimants should be carried out, whenever possible, after fraffic has dispersed

standing water. Successive normai or half rate treatments (for pre-wetled, pre-
coated and dry sait) may be considered, based on operational experience for
lightly trafficked roads at the lower end of the temperature bands indicated and
_| climatic variations experienced, |
4) Where @ surfacing is of an open lexfure and for porous or surface Water is evident
the higher spread raie (indicated in brackets} should be used. Where

| iemperalures may reach the lower end of the temperature bands, light traffic or a

2)

more cauilious approach to treatment is required based on operational experience,
local knowledge, the higher spread rate {indicated in brackets) may be used.

AANetwark Manayement(Nctwork Control ContreVMdlvenst 36
Weather ~ WMi19 14-30 13.7 Severe Weather

PlantWorking CapyiS TRA Adverse Weather Pla 13-14

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