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Management of incidents

Authorised Professional Practice

This page is from APP, the official source of professional practice for policing.

First published
Written by College of Policing
Roads policing
16 mins read

Forces are responsible for determining the structure and resourcing of their road policing capability so as to enable roads to be policed effectively, based on their strategic aims and targets. Incidents should be managed in accordance with CLEAR Keeping traffic moving (National Highways, 2021) principles. Decisions should be made in accordance with the national decision model.

Forces should identify locations, for example, bridges, tunnels and transport hubs with particular hazards and vulnerabilities within their force areas, and allocate specific threat levels to them. Where appropriate, these may require specific plans.

Roads can be a high-risk environment. Staff will, therefore, benefit from appropriate training prior to operating in the higher-risk environments, but this is not always a prerequisite if Article 2 of the European Convention on Human Rights (ECHR) is a consideration.

Conducting an initial incident assessment

The first officers or police staff attending a collision that has resulted in a road death and/or life-changing injuries must conduct an initial assessment and send a situation report to the control room. The control room will, if necessary, coordinate the deployment of supervisors and additional resources to the incident. Effective communication is paramount at this stage, along with considerations of potential safety issues. The mnemonic, METHANE, helps officers to conduct this initial assessment.

The initial assessment should consider the Joint Emergency Services Interoperability Principles (JESIP) in the early and continuing management of the incident. These principles have been developed between blue light responders and partner agencies. They identify the chain of command and responsibilities upon individual agencies to implement, review and effectively deal with incidents through the effective coordination and combination of their skills, assets and resources.

For further information see:

Dynamic risk assessments

Officers must conduct a dynamic risk assessment when attending incidents on roads. These assessments should consider the following.

1. Location

  • Position/visibility – is the carriageway position dangerous, for example, in lane three or on a bend?
  • Characteristics – is the location on an elevated or narrow section?
  • Traffic flow – is the volume and/or speed of passing traffic an issue?
  • Signs – are signs close and correctly set to assist?
  • Communication – is it effective and are any special arrangements needed between agencies?
  • Constraints – do any physical constraints of the locality make safe working difficult?

2. Vehicles

  • Number and type involved.
  • Suspicion – is there anything suspicious about the vehicle or contents?
  • Crime/intelligence – has the vehicle been involved in any reported criminal activity?
  • Condition – damage and extent and is any part of the vehicle or load obviously dangerous?
  • Hazards in the vehicle or load.
  • Other hazards.
  • Owner/driver – is the owner/driver present?
  • Occupants – how many/are all accounted for?
  • Lighting – is the vehicle unlit during the hours of darkness?
  • Any special recovery requirements?

3. People

  • Number involved.
  • Demeanour.
  • Condition – eg, are they trapped or injured and how badly? are they sober, drunk, suffering illness?
  • Comprehension – are they able to understand instructions or guidance given?
  • Crime – has a criminal record PNC check been completed, if so what is the result and are there any warning markers?

4. Localised factors

  • What has happened – is it likely to happen again?
  • Environmental factors.
  • Security/impact issues.
  • Equipment – what is available or needed?


Each feature of ACE CARD must be considered in sequence, but each one may not necessarily be implemented on every occasion. Advance warning of the scene is critical to the safety of those present, and takes precedence over all other action at the initial stage.

The ACE CARD mnemonic reminds responders of the steps they need to consider when dealing with road incidents. It stands for the following.


Whenever possible, all incidents on motorways and dual carriageway roads should be approached from the rear (when all lane running (ALR) is in effect, alternative approaches should be considered). Where a critical or major incident occurs, special circumstances may apply and the control room will inform officers on how to approach the scene.

The first officers at the scene are expected to put into place the immediate safety measures, control the incident and be responsible for the overall management of the scene until relieved by a more suitable incident control officer, if required.

– caution signs

Early advanced warning of incidents ensures a safer scene for attending units.

Control rooms or regional control centres (RCCs) in England should display the speed limit and/or lane closures required on variable message signs (where available). Police officers should be trained to place signs and cones correctly. The incident commander should encourage partner agencies to update and/or remove any emergency traffic management measures in a timely manner.

The main methods of positioning a police vehicle on the carriageway are:

  • in-line – the police vehicle is parallel to the running lanes on the carriageway. This maximises rear-facing lighting and rear vehicle markings
  • fend-off – the police vehicle is angled, pointing front end towards the carriageway in the direction the traffic should pass. This method fills the lane that is going to be closed, and also acts as a visual reinforcement of the cone taper. It appears stationary to the approaching traffic
  • fend-in – the police vehicle is angled, pointing front end toward the nearside in the direction the traffic should pass. This method fills the lane that is to be closed and acts as a visual reinforcement of the cone taper

Officers should be aware that the effectiveness of rear-facing lighting on the police vehicle is reduced, as is their visibility of approaching traffic during fend-off and fend-in.

On roads with a speed limit of more than 40 mph, the police vehicle should be positioned at a minimum of 50 metres to the rear of any carriageway hazard. When providing advance warning of a scene, police vehicles should always remain unoccupied.

When out of vehicles, officers must (unless the policing purpose is frustrated):

  • wear high-visibility safety clothing
  • deal with motorists from the safest side of the vehicle

The early notification to road users through a range of mediums, for example social media should be considered. Where there are no matrixes or variable message signs (VMS), staff should consider the benefits, practicalities and risks of placing warning signs on the central reservation. Before erecting equipment, a dynamic risk assessment should be undertaken. It may be necessary to deploy a full rolling road closure on approach to the scene.

When locating signs, the following minimum distances should be observed.

Speed limit Distance from the start of the cone taper
70 mph (motorways) 300 metres 600 metres 900 metres
50 mph to 60 mph 300 metres 600 metres 900 metres
40 mph to 50 mph 200 metres 400 metres -
30 mph or less 50 metres - -

Consideration should be given to placing signage at 900 metres to further enhance safety. 

Whenever possible, signs should be placed to give a clear view of at least 100 metres to the first sign. On single carriageway roads, warning signs should be placed on both approaches to the scene.

 examine the scene

After providing sufficient advance warning, the scene should be examined to determine whether further assistance is required. Normally, the first officer at the scene acts as the communication link, and liaises with partner agencies to prevent duplicating requests.

In examining the scene, the mnemonic METHANE should be used to consider the key points systematically. This assessment should be repeated at regular intervals when new information becomes available.

– casualties

An early check should be made to ensure that all casualties have been located. Consideration should be given to using other resources, for example, an air support unit or police search dog units to assist in the search for casualties or the deceased. See Investigating road deaths.

Details of casualties should be obtained before they are removed from the scene where possible. If the injuries are considered life threatening or life changing, it may be necessary to deploy a continuity officer.

 ambulance, fire and rescue and other partnership agencies

The cooperation of all emergency services and other partners is required to maintain free passage to and from the scene, and to keep traffic moving at a safe speed. In a multi-agency response that requires police attendance, coordination and scene management rests with the police. They must inform the other partners of any special road conditions at the scene at the earliest opportunity.

All services must share information relevant to the safety of personnel at the scene and the command of the incident.

– remove the obstructions

The police are responsible for securing evidence at the scene of an incident on the road. No vehicle should be removed from the scene until the investigating officer is satisfied.

Incidents should be managed in accordance with CLEAR Keeping traffic moving (National Highways, 2021).

The recovery operator’s incident manager should still be notified of the anticipated need to allow them to plan a suitable response.

Considerations include:

  • staff should not manually handle vehicles unless there is a risk to life
  • control rooms should use authorised, nominated recovery operators
  • staff outside of vehicles (see C – caution signs)

– detailed investigation

When investigating serious collisions see Investigating road deaths.

Collision investigation

Investigations into collisions which result in little or no injury are investigated by an investigating officer, who collects evidence from the scene and prepares an accident report. Collisions resulting in a road death(s) or likely to result in a road death(s) require a roads policing lead investigator (RP lead investigator).

Roads policing officers should be aware of:

  • liquid petroleum gas – advice must be taken from the fire and rescue service (FRS) and/or a suitably trained police hazmat adviser
  • rollover protection system
  • hybrid vehicles – officers should seek advice from the FRS before touching the vehicle
  • environmental conditions which may affect driving, for example, snow and ice, flooding, high winds and fog
  • supplementary restraints systems (airbags) – officers should be aware of these systems and the dangers posed by them. If there is any doubt at a scene, advice should be taken from the fire and rescue service

Fire on the carriageway

When a vehicle is on fire, police officers should:

  • cone off and sign the lane(s), to create a sterile working area for the FRS, while having regard to their own safety
  • remember their own and the public’s safety – if smoke is present, it is likely to be highly toxic and can affect a wide area
  • on motorways, close lane one when the burning vehicle is on the hard shoulder so that the FRS can carry out their duties

Officers should be cautious of the chemical changes that occur when a vehicle is on fire. When dealing with any fire damaged vehicle or component, either at the roadside or during a later vehicle examination, officers must wear protective gloves. These must be disposed of safely after use.

If contamination is suspected, officers should thoroughly irrigate the area with water, apply hydrofluoric acid antidote gel if available, and seek immediate emergency treatment.

Carriageway and road surface

Repair or improvement on the carriageway is planned by the highway authority in consultation with partners. Stopping vehicles in works areas must be avoided. Coned-off areas where people may be working should not be used by police vehicles, except in cases of extreme emergency. Contractors may mark out an emergency lane for the police and other services to use.

Patrols should report any carriageway faults, for example, potholes, collapsed areas or sections of safety barriers that have been damaged. Cones placed near a damaged barrier indicate that the highway authority has been notified and no further police action is required.

When dealing with a collision that involves damage to street furniture, the precise location must be identified using any reference numbers found on the item. The vehicle that caused the damage must be noted in any report. This enables the Highways England or local highway authority to correctly pursue a claim for repair work.

Removal of debris

Removal of debris on specified roads and motorways is primarily the responsibility of Highways England traffic officers. If police officers find debris and decide to remove it, they must assess whether they are equipped and capable of doing so without taking excessive risks. They should ensure that advanced warning signs are set, if available.

When removing debris, officers should:

  • not turn their backs on traffic
  • consider whether a temporary road closure is necessary
  • consider a rolling block on motorways and dual carriageways (if trained to do so)
  • use protective equipment

Where officers have to stop on a hard shoulder or verge to clear debris from a live carriageway, they should stop 50 metres before the debris. If the debris appears to be hazardous material, officers must take extreme care and consider closing the road. Special advice and early access by local authorities may prevent more costly road repairs being required and reduce the duration of closure.

Vehicle loads

Some loads transported on the road network may be considered to be dangerous goods or abnormal loads. An abnormal load is restricted to a notified route and should not be diverted or re-routed without prior consultation with the police. In the case of heavy loads (generally over 44 tonnes) Highways England and bridge authorities must also be consulted. The force control room will be informed of any such movements. If it is a vehicle with an abnormal load, authorisation is required from the Department for Transport (DfT). If a heavy load becomes immobile on a bridge or overpass, the highway authority should be informed.

The following should be considered when dealing with dangerous goods or hazardous materials.

  • Those involved in specialist escorts should carry dangerous goods identification guides.
  • The scene of an incident should be approached upwind and from a down gradient if possible. The wind should be blowing on the officer’s back while facing the incident.
  • The FRS should be informed of all suspected incidents involving dangerous goods.
  • Police officers should not become involved in rescue as they are not equipped to deal with chemicals.
  • If officers suspect hazardous chemicals, the carriageway should be closed and cleared for a considerable distance. It is usually be necessary to close the opposite carriageway as well, unless they are separated by a considerable distance.
  • All unknown loads or substances must be treated as hazardous until it is known that they are safe.

For further information see Association of Chief Police Officers (ACPO) (2010) Guidance/Practice Advice on the Movement of Abnormal Indivisible Loads.

Escort vehicle

An escort vehicle is usually required in the following situations.

Measurement For motorways For all other roads
Load/vehicle width exceeds 4.6 metres 4.1 metres
Overall vehicle length exceeds - 30.5 metres
Vehicle gross weight exceeds 130 tonnes 100 tonnes


The Motorway Traffic Regulations (England and Wales) 1982 control the use of motorways. Regulation 16 (as amended) provides exceptions and relaxations to the regulations. Patrolling officers need to be aware of these exceptions and mindful of what partner organisations are permitted to do under these regulations. The exemptions include persons under the direction of a constable in uniform or a Highways England traffic officer in uniform.

A partial or full closure of a motorway causes delays, economic loss, displaced traffic congestion and increases the risk of collisions on diversion routes.

Key partners and the media must be notified of any closure to allow the travelling public to be informed and advised of any diversionary routes.

Forces should have a policy for the removal of broken-down vehicles. When carrying out any procedures on the hard shoulder, a lane one closure should be considered to ensure an adequate safety zone.

The occupant(s) of a broken-down vehicle should be given advice that maximises their personal safety, dependent on the prevailing circumstances.

Police should inform the regional control centre of any broken-down vehicles so that action can be taken.

Partial closure

There are two types of partial closure – individual lane closures and rolling roadblocks. Police officers who work in a motorway environment must be trained to implement a rolling roadblock. Individual lane closures must be completed in accordance with ACE CARD.

Full closure of a motorway

If the decision is taken to fully close a motorway, there must be sufficient resources to ensure that it is implemented effectively. A road policing officer can make the initial decision that the motorway should be closed, but a supervisor and the Highways England’s regional control centre and/or highway authority should be notified at the earliest opportunity so the decision can be reviewed. If the closure is likely to be lengthy, the highway authority will be asked to arrange for the initial closure to be replaced by a full closure in accordance with Department for Transport (2006) Traffic Signs Manual Chapter 8.

If the police implement full closure, the following should be undertaken.

  • Early notification to road users through a range of mediums, for example social media.
  • Emergency welfare of displaced and/or stranded road users.
  • Divert traffic along predetermined routes, which need to be checked for obstructions before using them.
  • Close all slip roads likely to affect the closure.
  • Visually check of all the closed area (to be completed by a patrol car officer) to ensure there are no broken-down vehicles or pedestrians present.

Hard shoulder

Officers should take the following into account when using this section of the road.

  • Driving on the hard shoulder (hard shoulder running) should be kept to a minimum.
  • It may be in use as a live lane.
  • There could be vehicles obstructing or straying into the hard shoulder.
  • Keeping to an appropriate speed.
  • The hard shoulder may be unsafe because of dirt and debris.
  • If attending a stationary vehicle, especially in darkness, the driver or another vehicle occupant may be walking on the hard shoulder.

Emergency refuge areas

These are to be treated as a break-out area from a live lane, for the safety of road users. Gaining access to and from emergency refuge areas (ERAs) presents an increased risk and may require assistance from the emergency services or partner agencies.

ERAs should not be used for non-emergency purposes.

Reverse flow

This is deployed when emergency or highways authority vehicles are required to travel the wrong way down the motorway, to access the scene of an incident.

Reverse flow needs to be carried out under strict guidance by specialists fully trained in motorway procedures. It can only take place once the motorway is confirmed as fully shut in the normal direction of travel.

Rolling roadblocks

A rolling closure is a traffic control measure which is used to gradually slow the traffic to create a gap in the flow, or bring the traffic to a halt. It can be implemented by using one patrol vehicle or more than one patrol vehicle driving alongside each other and blocking the lanes. All rear-facing emergency lighting must be illuminated to prevent vehicles passing. Consideration should be given to using motorway signs to provide advance warning of any build-up of traffic.

Considerations include:

  • officers carrying out this procedure should have received suitable training
  • at the start of this manoeuvre, the speed of the patrol car matches that of the traffic and then gradually and safely it is reduced
  • lifting a rolling roadblock – once the incident has been cleared, the patrol car in the offside lane will leave first, followed by the vehicle in the centre lane and lastly the nearside car. The block should be lifted gradually with the blocking vehicles building up speed over a distance of one to two kilometres before turning off their emergency lighting and returning to other activities

Emotionally and mentally vulnerable individuals

Emotionally and mentally vulnerable individuals may present a danger to officers, emergency service personnel and the public. The police should consider:

  • turning off sirens on approaching the scene (other emergency vehicles attending should also be requested to do this)
  • reducing speed on both carriageways to reduce the risk to motorists
  • stopping traffic on both carriageways
  • requesting two ambulances if a person is on a bridge over a road, so that medical assistance is available both on the bridge and the carriageway below
  • the assistance of expert negotiators
  • multi-agency support post incident
  • approaching the person with extreme caution and maintaining a safe distance from them. The person’s judgement may be distorted by having taken drugs or alcohol. They may also have concealed weapons on them


When the police become aware of a protest or potential protest activity, their response should be coordinated and the impact on the road network mitigated.

As protests may involve offences being committed or public safety concerns, they are police-led in accordance with Highways Agency and ACPO (2005) The Network Operations National Guidance Framework. Police should ensure that the guidelines are followed.

Air support

Police air support units are recognised as a key resource in the policing of roads and can be deployed for:

  • police pursuits
  • locating stolen vehicles
  • searches for missing persons
  • containment
  • high-risk prisoner movements
  • searches for suspects
  • casualty evacuation
  • policing of large events
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