Capturing Fast and Accurate Data for Highways England Area

Sun Hill Surveying and Engineering Ltd is a specialist Land Surveying and Engineering company with over 30 years’ experience, focusing on the civil engineering sector throughout the UK.  Delivering only the highest quality services through a portfolio of professional expertise, Sun Hill brings a modern approach to surveying with a unique combination of traditional and state-of-the-art technology.

Working closely with Leica Geosystems for over 20 years and investing heavily in Leica Geosystems products and solutions throughout this period; Sun Hill made a significant capital investment in the Leica Pegasus:Two in August 2015. Adopting this new mobile mapping technology from Leica Geosystems was a significant step for a growing company to invest in. Given their client base and smart ways of working, as well as the ever increasing pressures on the maintenance of the highways infrastructure, it made the investment in the Leica Pegasus:Two a necessity.

Highways England Area 3 project
Soon after this investment in mobile mapping technology, Sun Hill was approached and commissioned by Kier to survey 119 sites on behalf of Highways England Area 3. Area 3 is Highways England’s second largest network carrying around 10 per cent of the country’s overall traffic flows. It includes the M27, M3, M4, A3, A303 and the Hindhead Tunnel and provides the main link routes between several major towns and cities including Oxford, London, Reading and Swindon in the north, and Bournemouth, Southampton and Portsmouth in the south.

Challenge
The large scale project required detailed topographical surveys of the carriageway and verges, each survey measuring 600m long for the design and future replacement and installation of road signage for clearer visibility across the gradients on the road.  The topographical survey features for the design included the surveying of the carriageway extents, road markings, crash barriers, channels, top of kerbs, gullies, kerb weirs, verge levels, ironwork frames, sign locations, traffic loops, overhead cables, electrical boxes, railings, fences, steps, bridge soffit levels and pier positions.

To survey these sites traditionally is a long and protracted operation using laser scanners, total stations and GPS, to collect thousands of points of data per day. Typically, this would take a surveyor around 2 days per site to complete in the field.  Also to survey this many sites would have required 119 individual traffic management installations. With a project of this size, there is a significant health and safety risk associated to all involved, to personnel being both in the carriageway and in the verge during all times of the day and night.  A safer and more cost effective method was needed to deliver the project on time and in budget.

Data Capture through mobile mapping
Leica Pegasus:Two and the mobile mapping process have revolutionised the world of surveying.  Using the mobile mapping process and Leica Geosystems’ technology provided huge benefits to the Area 3 Highways England project.   Access to all sites was left clear with no road closures as the Leica Pegasus:Two acts in the same way as any other public vehicle when collecting the 3D geospatial data. In total, the surveyors travelled more than 13,000km using the Leica Pegasus:Two to collect millions of points per second.  There was no disruption to the network as traffic management was not required, allowing traffic flow to continue as normal.  Safety to survey personnel was considerably improved using mobile mapping as no surveyors or traffic management crews were needed in the road as all data was captured from the safety of the vehicle. The virtual surveyors were able to create traditional topographical surveys from point clouds.  Mobile mapping provided a rapid data capture solution for Kier, saving them time, reducing safety risk and maximising value by reducing a 200 field day project to 12 days with mobile mapping.

Results and Benefits
As a result of using the Leica Pegasus:Two, all 119 sites were surveyed in only 12 days, with no traffic management, allowing processing and extraction to be undertaken from the safety of an office environment.  Furthermore, all 119 sites were surveyed and delivered to Kier a week before the final deadline, thanks to the speed of accuracy delivered through using the Leica Pegasus:Two. The total project took 118 days to complete including field operations. Sun Hill was able to deliver this project with less than 20mm absolute accuracy.  The surveys were then delivered in a staggered program, allowing sites to be prioritised and enabling some sites to be delivered earlier than others.