Geo-spatial mapping of road surfaces
The challenge
According to statistics in the latest Department for Transport report Road Conditions in England 2014, £4.2 billion was spent on the maintenance of roads in England in 2013/14. Public satisfaction with the condition of our roads is at an all-time low and the need to maintain roads cost-effectively is pressing.
Current standard methods for surveying the UK’s highways are costly, involving a time-consuming investigation requiring lane closures, speed restrictions and associated hazards to personnel exposed to live traffic.
Disruptions to traffic flow, particularly on busy roads, brings substantial economic impact to the region and local community.
The project
CSIC has developed a novel method of geo-spatially mapping the condition of roads using highly-accurate and cost-effective sensing technologies that identify and prioritise defects in our roads.
CSIC’s unique mapping system has been developed in direct response to an engineering challenge presented by a geotechnical engineering client who required an accurate and detailed measurement of the surface of an 18-mile section of a three-lane road and hard shoulder. Data collected enables the client to identify and prioritise the areas of road requiring urgent maintenance.
The approach
The construction of the road, using concrete slabs covered with a layer of asphalt, meant remedial work required the excavation and replacement of the 5m x 3m slabs, making repairs costly and disruptive.
A previous survey of the road, employing a laser-scanning system, failed to capture defects on much of the road length and resulted in an inaccurate report which presented the road as essentially defect free.
Engineers needed a more accurate method of evaluating problems in the road in order to produce an effective risk-based maintenance and repair programme.
CSIC’s novel road mapping system uses sensors to measure road height changes and produces a detailed geomap of the road locations that exhibit sharp changes in height. The approach is cost-effective, requires only two people and takes less than half a day to complete. The resulting 3D-topographical map identifies the exact location and severity of problem areas as well as the impact on driving conditions. CSIC’s method offers a 10-fold increase in spatial resolution and identifies road defects more accurately than existing laser-based technologies.
The benefits
CSIC’s geo-spatial road mapping method requires no disruption to traffic and can be completed without imposing speed restrictions or road closures, saving asset owners money. Turnaround of survey results and mapping report is rapid and the database and map produced shows the precise locations and severity of road defects, prioritising the top 20 per cent of these faults.
The method is cost effective and enables engineers and asset managers to make more effective decisions to better use increasingly limited resources. CSIC’s geo-spatial road mapping method has the potential to be scaled-up to map extensive areas of road network.