Freddie Slater

REGULATION 28 RESPONSE TO PREVENT FUTURE DEATHS 

THIS RESPONSE IS BEING SENT TO: 

The Assistant Coroner for North West Kent, His Honour Alan James Blunsdon of Oakwood House, 
Oakwood Park, Maidstone, Kent, ME16 8AE. 

National Highways  

I am 
of Viables 3, Jays Close, Basingstoke RG22 4BS. 

, Head of the Vehicle Restraint Systems Team at National Highways Limited 

CORONER’S MATTERS OF CONCERN  

The MATTERS OF CONCERN are as follows: –  

(1) The grass verge which separates the M20 and M25/ M20 slip road does not have erected 
upon it any physical barriers to prevent traffic crossing the verge from either of the 2 roads 
referred to and entering a parallel lane the opposite side of the verge. 

(2) The evidence received from National Highways confirmed that under the present policy 
guidance, barriers would not normally be required as there are no features such as an incline 
on the slip road, bridge supports or trees requiring physical protection between the two 
merging roads of traffic travelling at similar speeds in the same direction. 

(3) The facts of the present case illustrate that in the event of a loss of control of a vehicle 
travelling on either the M20 or in the slip road there is the potential for that vehicle, without any 
warning to drivers travelling at or about the same area in the coastbound direction, cross the 
grass verge to their side and enter their lane of travel. As both the material roads are subject 
to the same national speed limit of 70MPH, the risk of a high speed collision and fatality arises. 

DETAILS OF ACTION TAKEN  

This note has been prepared in response to a Regulation 28 report, received from the North West 
Kent Coroner’s Service by National Highways in response to a fatal road traffic collision on 16 
October 2024. The incident occurred in the proximity of the link road connecting the M25 junction 
3 southbound carriageway to the M20 eastbound carriageway. 

Nature of the current barrier provision at the material location 

The current barrier provision at the incident location is unchanged from the time of the incident; 
prior to the Button Street overbridge, there is a barrier in the nearside verge of the entry slip road 
to the M20 from the Farningham roundabout (i.e. located between the Farningham roundabout entry 
slip road and the M25 entry slip road).  

Initially,  this  barrier  takes  the  form  of  two  single  sided  lengths  of  Tensioned  Corrugated  Beam 
(TCB) barrier. These have been installed to reduce the risk of injury to a road user from impacting 
the trees  between  the  barriers  and to reduce the risk of injury posed by the difference in height 
between the two carriageways.  

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 When there are no trees between the two slip roads, and the difference in height between the two 
slip roads presents no/little risk of injury, the barrier transitions into a double sided TCB barrier to 
close the gap which would otherwise have been left between the two lengths of single sided barrier, 
and the next length of barrier.  

Shortly, prior to the bridge pier supporting Button Street, the double sided TCB bifurcates (forming 
a Y-shape) into two single sided lengths of TCB.  

These lengths of single sided TCB are then transitioned into two lengths of single sided Open Box 
Beam (OBB) barrier which are then aligned around each side of the bridge pier. This is to reduce 
the risk of injury to a road user from impacting the bridge pier.  

Each length of the single sided OBB is then terminated after the bridge pier with an end terminal.  

Additional lengths of barrier are not provided after the bridge pier at the material location as there 
are no further hazards after the bridge pier; the height difference between the two carriageways is 
negligible, and there are no physical hazards present within the grass strip, such as a bridge pier, 
tree, lighting column or sign post.  

A  review  of  the  current  barrier  provision  at  this  locality  with  reference  to  current 
requirements 

National  Highways’  current  requirements  for  road  restraint  systems  (including  barriers)  are 
contained within the document CD 377 – Requirements for Road Restraint Systems. These were 
first  published  in  March  2020,  with  the  latest  revision  (revision  4)  published  in  January  2021 
(https://www.standardsforhighways.co.uk/search/1fe48581-82ba-4b6f-95a1-ee93309bd1b5). 

As identified in paragraph 5(2) of the Regulation 28 report, current design requirements would not 
require a barrier to be erected within the grassed medium between the M25 link and the M20 link. 

An assessment using the National Highways’ Road Restraint Risk Assessment Process (RRRAP) 
has been undertaken, and that has confirmed the merge arrangements do not constitute a hazard that 
would require protection by a barrier as traffic travelling down the M25 entry slip road and the main 
carriageway of the M20 are travelling in the same direction. 

The RRRAP identified that current design requirements would require a full height barrier to extend 
7.5  metres  beyond  the  Button  Street  bridge  pier  (as  the  bridge  pier  is  identified  as  the  hazard 
requiring protection). 

The existing length of barrier at full height beyond the Button Street bridge pier is approximately 
16.8 metres in the nearside verge of the M20, and approximately 9.6 metres in the offside verge of 
the M25 entry slip road. Hence both lengths of barrier beyond the Button Street bridge pier exceed 
the minimum requirement of National Highways’ current design requirements. 

It is also confirmed that the containment level of the barrier in front of the Button Street bridge pier 
is compliant with current requirements.  If it had been identified that a greater level of containment 
was required, this would have required longer lengths of barrier after the bridge pier (in order to 
accommodate the containment level of the system).  Again, this is not the case and both lengths of 
barrier  beyond  the  Button  Street  bridge  pier  exceed  the  minimum  requirement  of  National 
Highways’ current design requirements. 

 
 
 
 
 
 
 
 
 
 
 
 Barriers  present  a  level  of  injury  risk  to  road  users  and  are therefore  only  installed in  locations 
where a hazard cannot be removed, relocated, or made frangible, and the level of injury risk from 
the barrier is lower than the level of injury risk posed by the hazard located behind the barrier.  

Barriers also require installation, inspection, maintenance, repair and removal, all of which present 
a level of risk to our roadworkers, but also to the travelling public whilst temporary lane closures 
and speed restrictions may be in place to undertake such works. 

A review of similar incidents on the National Highways Strategic Road Network (SRN). 

A review of fatal incidents on the whole of the SRN in England has been undertaken to identify any 
other incidents where a vehicle has crossed over a strip at the end of the nosing at an on-slip road 
and impacted a vehicle on the adjacent slip road.  This search has been limited to fatal incidents as 
there is typically insufficient detail available for serious, slight and damage-only incidents in order 
to make a detailed assessment of the circumstances of the incident. 

The review of fatal incidents has identified a single event between 2014 and 2022 on the SRN, 
however in that incident, the fatality occurred to a member of the public who had left their vehicle 
due to a previous minor incident on the main carriageway. 

As a result, it is concluded that such incidents are uncommon on the SRN. 

A review of incidents at this locality 

A review of incidents in this locality has identified a single unrelated incident within the five year 
period from 1 October 2019 to 30 September 2024. The incident recorded was a ‘slight’ personal 
injury and from the description provided by the police, the road infrastruture (or lack of) was not a 
factor in this incident, and occurred in advance of the link road merge. 

TIMETABLE FOR PLANNED ACTION  

No further action is planned. 

SAFETY OF ROAD USERS  

The safety of our road users is an imperative for our business, and safety is a core value of our 
organisation. We are working hard to make our entire network safer.  

We consider that the action we have taken to date has confirmed that the length of barrier after the 
Button Street bridge piers meets current requirements.   

We have also identified that the circumstances witnessed in this incident are uncommon elsewhere 
on the SRN.   

Furthermore, we have also identified a single unrelated incident (of a slight personal injury) at this 
location (albeit in advance of the link road merge) within the five year period from 1 October 2019 
to 30 September 2024.   

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 We have also highlighted that barriers present a level of injury risk to road users and are therefore 
only installed in locations where a hazard cannot be removed, relocated, or made frangible, and the 
level of injury risk from the barrier is lower than the level of injury risk posed by the hazard located 
behind the barrier.  

All improvements to the SRN are required to be progressed in a considered and controlled fashion 
so that the consequences of changes to the SRN are fully understood and any linked safety risks are 
eliminated or reduced as far as possible. Furthermore, works to the SRN are required to demonstrate 
value for money, in accordance with the Highways England: Licence (April 2015), and our duty to 
manage public funds. 

As a result, it is not our intention to take any further action at this location, nor is it our intention to 
update the requirements for barriers at merges within CD 377 as a direct result of this incident. 

7  Signed and dated 

, 11th June 2025