Highways Agency

• Traffic Incident Management Bulletin

Removal of the central reserve is one method of relieving congestion following an incident and has been high on the Agency’s agenda in recent months.

The system has significant potential to speedily release traffic by sending it onto the opposite carriageway away from its desired direction of travel.

This method is championed by Derek Turner, Traffic Operations Director, who is eager that it is considered at every opportunity by all incident responders. One recent example took the practice a step further by ensuring traffic continued along its intended route.

At 9:45am on Tuesday 15th August, a Heavy Goods Vehicle (HGV) collided with a lorry a mile south of Junction 28 on the northbound carriageway of the M6. The lorry was loaded with pallets of aggregate, and had stopped on the hard shoulder.

Having impacted the aggregate lorry, the HGV veered across 3 lanes and hit the central column of the nearby overbridge, hitting another four vehicles on the way.

The accident blocked all three lanes and the hard shoulder covering the carriageway with diesel. Before long there were 7 miles of traffic backed up to J27, and a need to get everyone moving somewhere and soon; not least because of the warm weather.

Fortunately, none of the vehicles involved were carrying hazardous substances, no serious injuries were sustained, and as a result the southbound carriageway was unaffected.

The M6 was closed between J27 and J28. Congestion between J27 and Charnock Richard Services was alleviated by taking the traffic onto the service station forecourt; enabling motorists and passengers to rest and use facilities. However, approximately 6 miles of traffic remained, and carriageway repairs meant a minimum 12 hour closure to the road.

Insp. Phil Cottam of Lancashire Motorway Police was leading the incident and raised the idea of relieving traffic by taking it across the central reserve, up the southbound carriageway and back onto the northbound carriageway beyond the incident.

Stakeholders present were consulted as nothing of this sort had been done before and there was no formal plan in place as to how it could be undertaken. In spite of some reluctance by other responders, dialogue continued and, with mutual agreement, a plan between all parties was created.

Due to previous maintenance works on the road, redundant crossover points were positioned south of the incident and also a few hundred yards north of the bridge, with good line of sight between them. Whilst complete compliance with Chapter 8 would have been desirable, control measures were added to implement the contraflow more quickly to alleviate traffic as soon as possible.

A rendezvous point for stakeholders was established at J28, with one HA Traffic Officer team managing the point and another patrol escorting vehicles to and from the incident. An additional HA Traffic Officer patrol was positioned at Charnock Richard Services to provide information and updates to the motorists stranded there.

With agreement of all stakeholders, the temporary traffic management system for crossing the carriageway was set up.

1. On the southbound carriageway, a rolling block closure was instigated whilst the Traffic Management Vehicle travelled south down the northbound carriageway to the upper crossover point, where the barrier was removed. In the meantime, the HA Traffic Officers were organising the traffic south of the incident so that HGVs were occupying lanes 1 and 2 and domestic and light goods vehicles were in lane 3. See rolling block closure diagram.
2. With the barrier open, the Traffic Management Vehicle created a taper north of the cross over point and coned off lanes 2 and 3. Incident response, HA Traffic Officer and Police vehicles were parked in lane 2 to create a barrier between lanes 1 and 3. See Traffic Management diagram.
3. The rolling block was then removed from the southbound carriageway, and traffic was permitted to run in lane 1. The Traffic Management Team then removed the barrier from the lower cross over point. See southbound running diagram.
4. With all the Traffic Management in place, and the southbound carriageway running, HA Traffic Officers were positioned to marshal cars and light goods vehicles into, along, and out of the contraflow back onto the main carriageway. A HA Traffic Officer Supervisor was positioned halfway along the contra flow, in the line of sight of both crossing points, and radio contact was maintained between the officers at all times. See northbound contraflow diagram.

Throughout the day, local and strategic diversions were in place for vehicles travelling both north and south. An additional 10,000 vehicles were detected on the parallel running M61, whilst, in total more than 24,000 additional vehicles were detected on alternative routes.

Once all light vehicles and cars were cleared northbound, the TM team returned and reversed the changes they had made whilst a rolling block closure was undertaken in the southbound carriageway. HGVs were led past the incident in an opened lane, at controlled speeds, before carriageway repairs were completed.

The incident timeline developed as followed:

• 9.45am: Incident occurred
• 11am: Possibility of crossover discussed
• 12.41pm: Barrier down and HA Traffic Officers briefed
• 12.50pm: Traffic started running through the contraflow

Insp. Phil Cottam stated “This process had been considered in the past but not implemented, but on this occasion the circumstances were right and it worked well. This couldn’t have been completed without the Traffic Officers or the close working with the Highways Agency, Atkins and AmeyMouchel”.

Roy Wood, the Highways Agency Area Performance Manager for Area 10 stated “This worked well on this occasion, but we would like to standardise the approach to this type of emergency traffic management and look at the ability to run greater flows of traffic where able”.

There were a number of factors which made this incident a particularly good example to try this type of contraflow, and whilst it would not be suitable for all types of incident, it does highlight a lot of factors which would need to be considered before implementing such a process. In all instances, Dynamic Risk Assessments are of paramount importance.

The following list gives an indication of the items which would need to be considered if it might be possible to undertake this process for another incident. It should be noted that this list is not exhaustive, and other factors or options appropriate to the specific situation would also need to be considered.

• Time of day
• Current Traffic Flow
• Number of lanes (and condition of hard shoulder) on opposite carriageway
• Availability of staff and vehicles
• Proximity to Junctions
• Available crossover points
• Line of sight between possible crossover points
• Duration of required closure
• Severity of incident
• No other suitable alternative
• Agreement from all parties i.e. Police, HA, MAC, Traffic Officers etc.

Further considerations, along with other options that may be more appropriate in some circumstances, are available in the guidance being developed by the TIM Programme. This will be released on the Traffic Officer Service WwW portal site over the next few weeks. For details prior to that release email the TIM Bulletin address.