Closing lanes for safety
Road workers are often out on busy trunk roads in all weather conditions. To protect them and keep road users safe, closing lanes to traffic is often necessary.

The OCs are required to keep the number of lanes closed to a minimum by completing as many tasks as possible within each closed area. They also plan works to be carried out during off-peak periods to reduce delays for road users.

2.1 Planning roadworks

Transport Scotland’s budget for capital investment in the trunk road network for maintenance and improvement was £168.5m in 2007/08. This was marginally lower than the previous year, as can be seen in figure 8.

Figure 8 Capital investment budget for maintenance and improvement

This budget is allocated to maintenance and improvement schemes through the OC contracts. It is the responsibility of the OCs to programme all works on the trunk road network to minimise the level of disruption and inconvenience to all road users.

The delivery of this investment programme is pivotal to a safe, efficient, reliable and environmentally acceptable network that meets current and future needs of road users.

Overall the OCs managed 13,146 individual roadwork sites, which is an average of 36 roadworks sites per day. Figure 9 provides a breakdown on the number of roadworks sites managed by each OC during 2007/08.

Figure 9 Number of roadworks sites managed by the OCs

To cope with increasing traffic volumes, OCs used a variety of measures for major works to minimise delays, maintaining reliability and network wide safety. These included:

• Traffic management measures such as contraflows, use of temporary vehicle restraint systems (see figure 10), lateral safety zones and convoy working.
• Advance notice of roadworks using media campaigns and placing of signs advising of start dates and durations of the works.
• Average speed cameras to reduce speeding through roadworks sites.

The OCs measure and report lane occupations for roadworks via a Key Performance Indicator (KPI), which is calculated by multiplying the number of lanes closed by their length in kilometres. This figure is then multiplied by the number of hours the lanes were closed. This can then be used to calculate the overall percentage of the network available.

Figure 10 use of temporary barrier to protect workforce on M77 scheme in SW

As can be seen from figure 11, the OCs continued to perform well in keeping the trunk road network open throughout 2007/08, with an overall accessibility of 99.20%. This is marginally down on last year’s figure of 99.4%.

Figure 11 KPI reporting road occupations and percentage of network available to road users

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