GNSS for Road Signage Survey

Before testing the system, the Council's Traffic Safety Team looked at various ways of carrying out the review and consulted with a number of different Local Highway Authorities.  

Owing to the legal requirements and interpretation issues of the order, they decided to use a high-accuracy GPS to collect the site information, which could then be easily transferred to their corporate ESRI GIS. Using GPS at this stage would also benefit the Council's eventual move to ‘map based' orders.

Already familiar with Trimble technology and KOREC's service and support, Northumberland County Council's Traffic Safety Team tested a Trimble R8 with VRS Now to ensure that the system met accuracy, software flexibility, ease of use for the surveyor, and for an engineer (so that preloaded data on the controller could be taken on site and orders updated following resurfacing etc.), straightforward downloading and ability to validate collected data.

Independent Consultant for the project, Terry Luck, explains. "Our Team has a lot of experience in building in-house Asset Management Systems for Highways, so we knew exactly what we wanted a new system to deliver - the Trimble system met all our criteria. The main benefit is that we need just one surveyor to carry out the work and that we can capture a huge range of useful positional and attribute information due to the flexibility of the software. Not only are we recording line colour, width, type, sign type, size etc, but also non TRO information such as condition, which I feel provides a platform for greater use of the system in that it now interfaces with maintenance work orders.." 

Once collected, the surveyor downloads the data and makes his initial edits the same day as the survey. The data is then loaded into Northumberland's GIS using ESRI's Arcview and checked again.

By using the R8 in conjunction with Trimble's VRS Now Service, the Traffic Safety Team has been able to benefit from instant access to RTK corrections without the need for, or additional cost of a base station. The system is consistently achieving +/-10-15mm, only having limited problems when surrounded by very high buildings - any issues were quickly identified in the first stage of validation checks.