A83 Rest and Be Thankful - Managing Trunk Road Operation

Following the significant landslides that happened in August and September 2020, a bespoke operational strategy has been implemented to allow safe use of the A83 at the Rest and Be Thankful.

To carry out this strategy, BEAR Scotland collects a range of detailed information so that safe operation of the route can be planned, put in place and maintained for all road users.

The information collected on a daily basis includes:

  • Expert weather forecasting data
  • Site team observations on hillside condition and watercourse flows
  • Hillside movement and monitoring data using on-site surveys
  • Ground saturation estimates
  • CCTV imagery of the hillside
  • Trunk road condition data.

This information supports pre-emptive planning and decision-making for road operation. The hillside is monitored continuously by spotters (during the day) and roadside sentries (at night).

Traffic management operations

Road user safety is paramount. BEAR Scotland and Transport Scotland consider the forecast weather conditions and live information from the site on a daily basis to determine the most appropriate measures to protect road users and operatives.

Specialist traffic management teams use a range of traffic management responses to maintain connectivity at the Rest and Be Thankful, including:

  • A83 traffic signal operation – when weather and hillside conditions are favourable, traffic signals are used to control vehicle movements along the single lane section of the A83 where hillside mitigation works continue to be undertaken
  • A83 convoy control
  • Operation of the Old Military Road (OMR) local diversion route under alternate convoy working
  • Dedicated recovery services are stationed on site 24 hours a day to attend to any incident or breakdown that may occur.

Decision-making process

When hillside conditions become more challenging or when inclement weather is forecast, a number of factors are considered as part of the operational decision-making process, including:

  • Extent of rainfall, its timing (day/night) and intensity
  • Rate of surface water run-off from hillside watercourses
  • Presence of brown water in hillside watercourses – this indicates possible movement
  • Indications of abnormal hillside movements from inspections and site surveys
  • Estimated hillside saturation levels.

Traffic management response during challenging conditions

Every effort is made to maintain traffic on the A83. Inclement weather and the effect that this can have on the hillside can result in convoy operation being implemented, allowing the trunk road to remain in use as long as it is safe to do so.

The benefits of convoy operation include:

  • A greater level of control over traffic movements on the A83
  • Constant communication about hillside conditions between traffic management operatives, hillside spotters and roadside sentries
  • A physical ability to stop traffic in a safe location while appropriate inspections are undertaken.

Where there is concern regarding the ability to operate the A83 due to weather and hillside conditions, consideration is given to diverting traffic to the Old Military Road as a safety precaution.

Only in exceptional circumstances, where hillside conditions are deemed to pose significant risk, is use of the Strategic Incident Diversion Route via the A82/A85 considered.

Communications

Various communication channels – including stakeholder updates, media releases and social media updates are used to highlight significant changes to operational arrangements on the A83 at the Rest and Be Thankful, to keep interested parties informed.

Road users are encouraged to plan ahead before setting out on their journey and should obtain up to date information from Traffic Scotland at www.traffic.gov.scot or on Twitter at @trafficscotland.