Transport Scotland Specifications – HDS Technology Selected by all Contractors

Transport Scotland are the first overseeing organisation worldwide to have released specifications that mandate the use of automated quality assurance technology during road maintenance and construction. Three asphalt contractors, Breedon, Aggregate Industries and Tarmac, all turned to HDS to help them comply with the new specifications and HDS now operate 16 paving crews across the whole of the Transport Scotland network through their technology.

The Transport Scotland specifications can be broken down into three areas: e-ticketing, paver monitoring and roller monitoring. The details of which are as follows:

eTicketing

All material must be ascribed a digital conveyance note at the point of dispatch from the asphalt batching site. The material must then be tracked on its way to site and the point of discharge into the paver marked with GPS co-ordinates. This approach is designed to reduce human error when constructing manual laying records, and to digitise data so that it can be uploaded easily into pavement management systems (PMS). A further advantage of this technology is that, by providing paving crews with real-time information about when the next load of material will reach site, site operatives can better regulate paving speed and reduce thermal segregation – a key cause of early pavement degradation and potholes.

Paver Monitoring

Transport Scotland require the use of a number of different paver monitoring technologies. Paver movements are tracked using GPS and weather stations provide local environmental information.Infra-red temperature sensors provide continuous monitoring of asphalt delivery temperatures and a backwards facing thermal imaging camera measures the temperature of material across the mat as it moves out from the paver screed. These technologies ensure that assurance information is captured in quick, reliable, granular detail, helping site operatives to make smart decisions in real time. The systems also remove the need for materials technicians conducting manual materials testing – helping to improve site safety and reduce costs for contractors.

Roller Monitoring

The Transport Scotland specifications mandate the use of high accuracy GPS systems to monitor the movement of rollers so that a record if made of the number of passes each square metre of asphalt under compaction is exposed to. In addition to the GPS systems, rollers must be fitted with infra-red temperature sensors to continuously monitor rolling temperatures. HDS conduct correlations with density gauges and cores to establish a target number of passes for each material under compaction. Roller passes and rolling temperatures are made available to roller drivers in real-time to ensure that they have a clear methodology to achieve perfect compaction. As with the e-ticketing and paver monitoring technologies, the roller monitoring systems help contractors build higher-quality, longer lasting roads without the requirement to put materials technicians out on site.

Technology Used in Addition to the Transport Scotland Specifications

HDS laser surveying systems are employed alongside technology mandated by Transport Scotland specifications. Contractors use the laser surveying systems to replicate and improve on testing usually carried out by materials technicians. The systems run at traffic speed and produce highly accurate measurements of surface macrotexture and surface regularity, removing the requirement for putting materials technicians in danger conducting traditional sand patch and rolling straight edge testing.

The deployment of HDS technology into the Scottish road market has been an overwhelming success for the whole asphalt supply chain. Data is made available in real-time to asphalt contractors to help them ensure that maintenance and construction is done right the first time, managing agents are provided with granular information about the performance of their subcontractors and Transport Scotland receives high-quality digital quality assurance data for use in asset management and deterioration modelling.

HDS technology is saving over 25% compared to the conventional provision of materials technicians and has successfully reduced HSE liability on site. Click here to find out more about the technology being used to comply with the Transport Scotland specifications: www.highwaydata.co.uk/products/