APPENDIX B – TRANSPORT SCOTLAND PROCEDURES

TRUNK ROAD NETWORK

The Application of the National Guidelines to the Motorway and Trunk Road Network

The purpose of this appendix is to provide an example of how the Transport Scotland will apply these guidelines to effectively manage instances of high wind on the Scottish motorway and trunk road network. This process will not only focus on the roles and responsibilities of the stakeholders involved, but also concentrate on the elements of pre-planning and the procedures to be adopted and pre-agreed to ensure the safety of travellers and road users in the event of an incident. The roles of the trunk road maintenance organisations, bridge boards, local authorities, the police and the Traffic Scotland control centre will be identified.

The remainder of the section details the approach taken by the Transport Scotland towards the implementation of the ten steps identified. It should be noted that the scope, complexity and level of effort required to manage each step will be site specific and will largely be dependent on the scale of the perceived problem at each location.

Step 1 – Risk Identification

Transport Scotland will undertake an initial review of the trunk road network to identify sections at risk from high wind. This review will include stakeholder consultation, review of accident statistics and other specialist services such as wind profiling and climate trend analysis to identify all potential risk areas.

Step 2 – Organisational Arrangements

Transport Scotland will encourage the development of organisational arrangements to clarify the role/responsibilities of each stakeholder prior to, during and after an incident for that ‘key’ section of road. For the trunk road network, Transport Scotland will require that the appropriate trunk road maintenance organisation be responsible for the initiation and maintenance of the organisational agreements. These agreements will incorporate, where appropriate, the bridge boards, the relevant police force, local authorities and the Traffic Scotland control centre.

The local agreements will clarify the decision making process and critical path for information dissemination.

Step 3 – Diversion Route Planning

Transport Scotland will make the trunk road maintenance organisation responsible for the preparation of diversion route plans for each site on the trunk road network.

The trunk road maintenance organisation will identify, where possible, alternative routes for the various classes of diverted traffic as a result of extended closures or restrictions. Where alternative routes are not available, the trunk road maintenance organisation will identify locations for parking of the traffic which cannot continue the journey during the high winds.

The trunk road maintenance organisation will ensure that effective information dissemination is built into the response plans. This is to ensure that the opportunity is given to allow travellers to make informed travel choices.

The trunk road maintenance organisation will assess the alternative routes for high wind impact before they are brought into use. During the high wind incident, the trunk road maintenance organisation, or other agency as agreed in the local wind management procedures (e.g. local authority), will monitor these routes to ensure they are not experiencing similar effects to the problem site.

Although the trunk road maintenance organisation is responsible for the preparation and management of any diversion routes, these will be developed, implemented and maintained with full consultation with the relevant police force, Transport Scotland, local authorities, bridge boards and the Traffic Scotland control centre.

It should be noted that the decision to implement a particular diversion route rests with the local police force (who should consult the relevant road authorities). Consideration in making this decision should be given to the time required to implement and travel to the diversion. These times should be compared to the expected duration of the restriction or closure before deciding to implement a diversion.

Step 4 – Monitoring

For each location identified as being ‘at risk’, the trunk road maintenance organisation will be responsible for the predictive and active monitoring of the wind conditions during the lead up to, escalation of, and relaxation of, high wind incidents.

The trunk road maintenance organisation will set up agreements with meteorological forecasters to obtain severe weather warnings in advance of high winds occurring. This will permit them to adopt a ‘state of alert’ and prepare for the impact of wind and the restrictions to be implemented.

In order for the trunk road maintenance organisation to monitor effectively the real time wind conditions, they must identify if there is adequate meteorological equipment to provide the data. Meteorological sites located on the road network in the proximity of the site can be used to facilitate the implementation of specific actions, according to developed procedures, once predetermined thresholds have been reached.

The trunk road maintenance organisation will undertake a review of any existing meteorological equipment to ensure that it is adequate for the job. It may be that existing equipment may need to be relocated or upgraded. If no existing suitable meteorological equipment is available, the trunk road maintenance organisation will liaise with Transport Scotland with respect to the procurement of a suitable facility.

The trunk road maintenance organisation will review the alternative routes to determine if they are in turn susceptible to high wind. If such routes are, then the trunk road maintenance organisation, or local authority as appropriate, will consider the requirement for additional meteorological equipment on these routes.

Step 5 – Define High Wind Level Thresholds

The trunk road maintenance organisation will identify the wind threshold conditions that will trigger the onset and removal of restrictions on the affected road. In order to choose the appropriate wind thresholds, the trunk road maintenance organisation may access specialist meteorological expertise. Such thresholds are to be agreed with Transport Scotland and the local police force.

The trunk road maintenance organisation will take into account the increasing or decreasing trends of the relevant wind conditions when determining what thresholds should trigger the implementation and relaxation of any restrictions.

Step 6 – Develop the Levels of Restriction

The trunk road maintenance organisation will determine the level of restrictions through consultation with Transport Scotland and the local police force. When the level of restrictions has been agreed, the trunk road maintenance organisation will be responsible for deploying traffic management for the restrictions (but not enforcement, see Step 7). As such they will be required to liaise with the police and Traffic Scotland control centre, as well as any affected road authorities, to inform of a proposed restriction prior to its implementation.

Step 7 – Enforcement

The responsibility for enforcement rests with the police forces. The trunk road maintenance organisation will ensure that traffic management for the restrictions to vehicle classes or complete road closures have been agreed with the police and that the statutory powers they require are in place. Close liaison with the Traffic Scotland control centre will be required to implement any strategic variable message sign setting to provide sufficient advance warning of restrictions. These actions can help reduce the demands on police resources during restrictions or closures.

Step 8 – Implementation of Traffic Management

The trunk road maintenance organisation will be responsible for the implementation of the traffic management deemed necessary for the restrictions or closures. This will require agreement with and instruction from the local police force as appropriate. The level of traffic management required and the procedures should also be agreed between the road maintenance organisation, the local road authority and Transport Scotland. The scale of traffic management required will be site specific and dependent on location.

Local traffic management procedures including alternative routes will be agreed in advance with all relevant bodies including the Traffic Scotland control centre. It is essential that the trunk road maintenance organisation ensure that the alternative route is suitable for the purposes, i.e. that it does not suffer the same problem and has sufficient capacity to accommodate the additional traffic. Procedures must also formalise the provision of feedback from the trunk road maintenance organisation to the Traffic Scotland control centre and the local police for all periods leading up to, during and after any restrictions.

Step 9 – Information Dissemination

Building upon the critical path for information dissemination (identified in Step 2 – Organisational Agreements), Transport Scotland will require the trunk road maintenance organisation to implement formalised information dissemination procedures. As part of the procedures the Traffic Scotland control centre will issue updates of restrictions and closures to the trunk road maintenance organisations, bridge boards and affected local road authorities. In parallel, the Traffic Scotland control centre will also update other parties including local radio stations.

This step is key to successfully managing a high wind incident as it enables the Traffic Scotland control centre to monitor and manage the status of the trunk road on a nationwide basis with a focus upon the trunk road network and those roads that impact upon it. This will ensure that the Traffic Scotland control centre are best placed to inform the travelling public in the most efficient manner.

Step 10 – Relaxation of Restrictions and Information Dissemination

The trunk road maintenance organisation will be responsible for the relaxation of any restrictions as agreed in the procedures from step 5 above. It is important to note that this task is as equally important as the initial implementation of restrictions, with the key element being the real time dissemination of information. Transport Scotland will require that the trunk road maintenance organisation prepares an agreed procedure to liaise with the police and the Traffic Scotland control centre to confirm acceptance of the relaxation. Similar to Step 9, timely involvement of the Traffic Scotland control centre will ensure that the travelling public can be promptly informed.