Trial site selection

In support of the research, an initial analysis by Transport Scotland of the Trunk Road Network identified 660 collisions involving motorcyclists between 2013 and 2017. Using STATS19 data (reported directly from Police attending accident scenes) the work highlighted the North-West region as a priority area for motorcycle casualty reduction.

Following this, BEAR Scotland Ltd (North-West Unit) conducted an in-depth review of collision cluster sites between 2008 and 2017. This work identified sites within a 100m radius where three or more personal injury accidents (PIAs) involving a motorcyclist or pillion had occurred (Figure 2).

Chart showing distribution of injury motorcycle collisions on trunk roads. The highest number of casualties are on the A82 (30) and A85 (19).
Figure 2: Motorcycle casualty profile for the North-West Region

For more information on the review of collision cluster sites please refer to BEAR (2019, 2021)

With a focus on the A82, A85 and A83, sites were identified in the region ranging from Glencoe, Oban, Inveraray, Loch Lomond and towards Stirling and Crieff (Figure 3).

Map of Scotland showing the location of PRIMEs trial sites as described in the text above.
Figure 3: PRIMEs trial sites

Expert reviews were conducted for each potential site (e.g. complex geometry, tightening or double apexes, descents and inclines prior to bends, bends off fast sections of road) and 22 trial sites were identified and categorised as motorcycle cluster (MCL) sites or PRIME trial (PT) sites.

In addition, BEAR Scotland produced a checklist of site characteristics that each trial site was scored against to identify suitable locations and to also help plan the scheduling of any upgrades required.

The trial sites were spread over a large geographic area of approximately 750 square miles. They represented a range of bends on rural roads with speed limits over 40mph in line with recent casualty statistics (Transport Scotland, 2020).

Two comparison sites were also included in the trials where data were collected but PRIME road markings were not installed. The comparison sites were of a similar standard to the PRIME trial sites. Due to the wide variety of bends and road characteristics on the Trunk Road Network, these comparison sites were not regarded as experimental control conditions (i.e. where identical conditions are usually compared statistically). All trial sites were brought up to similar standards prior to data collection. A summary of the PRIMEs trial sites is presented below.

Table one

PRIMEs trial sites 2020
Site Code Road Heading Bend type
Appin House - north PT-05 A828 North Left-hand
Appin House - south PT-06 A828 South Left-hand
Kingshouse - north PT-07 A82 North Right-hand
Kingshouse - south PT-07 A82 South Left-hand
Loch Lubhair - east PT-04 A85 East Left-hand
Loch Lubhair - west PT-04 A85 West Right-hand
Rob Roy's Dip - east 1 PT-03 A85 East Right-hand
Rob Roy's Dip - east 2 PT-03 A85 East Left-hand
Rob Roy's Dip - west 1 PT-03 A85 West Right-hand
Rob Roy's Dip - west 2 PT-03 A85 West Left-hand
PRIMEs trial sites 2021
Site Code Road Heading Bend type
Taynuilt - west MCL-04 A85 West Left-hand
Inveruglas - south MCL-11 A82 South Left-hand
Runacraig - north MCL-21 A84 North Left-hand
Runacraig - south MCL-21 A84 South Left-hand
Dunira - west MCL-08 A85 West Left-hand
Bonawe - east MCL-07 A85 East Left-hand
Landrick Bends - comparison n/a A84 North Left-hand
PRIMEs trial sites 2022
Site Code Road Heading Bend type
Dailnamac - east PT-20 A85 East Left-hand
Pulpit Rock - north PT-11 A82 North Left-hand
Butterbridge - north PT-02 A83 North Left-hand
Middle Kames - south PT-12 A83 South Left-hand
Salmon Draft - north MCL-03 A83 North Left-hand
Salmon Draft - south MCL-03 A83 South Left-hand
Carrick - comparison n/a A83 North Left-hand
Dunira - revisited from 2021 MCL-08 A85 West Left-hand
Rob Roy's Dip - revisited from 2020 PT-03 A85 West Right-hand

Images from a selection of the trial sites are presented below (Figure 4).

A selection of six images showing some of the left-hand and right-hand bend trials sites where PRIME road markings were installed throughout 2020 to 2022.. In all of the images a motorcyclist approaches the bend and there is Scottish highland scenery in the background.
Figure 4: Selection of trial site images

These images illustrate some of the left-hand and right-hand bend trials sites where PRIME road markings were installed throughout 2020 to 2022.