A key challenge in SRUS design was identifying the SRN roads that users had travelled on, and which Highways England Areas they had travelled through. Earlier surveys of this type used paper maps, which were time consuming to deploy, many maps were needed to cover all of the roads in England and they required manual decoding of which Areas the journey included.
Transport Focus wanted to increase the number of SRUS respondents across greater parts of England and to cut survey interview time in half. This required a digital mapping solution to integrate journey details into the survey software. Beacon Dodsworth were appointed to build the interactive map that could be embedded in the survey software.
After evaluating survey methods, Transport Focus decided that the most appropriate approach would be a home-based, face to face, random location survey.
Beacon Dodsworth worked with Transport Focus’ appointed research agency, Kantar TNS, to create a mapping tool that could be used within their Computer Assisted Personal Interviewing (CAPI) system.
They faced three fundamental challenges in providing a solution:
- Simplicity: the mapping software needed to be simple for quick, on-site use, while being flexible enough to capture non-trivial journeys.
- Integration: survey software usually includes very rigid coded or tabular data. Journey data has more structure, so bridging software is necessary in order to integrate it into third party survey software.
- Data volumes: the road network for the UK has over 4 million road links. There are 1.7 million postcodes. All of these needed to be included but, critically, they needed to differentiate those on the SRN and those that formed other parts of the journey. This is more difficult on a relatively small tablet device.
Beacon Dodsworth’s initial interactive mapping solution was developed for use in a browser for online surveys. However, when they reviewed the range of locations where potential respondents would be interviewed, they found that not every place would have an accessible or fast enough internet connection. They had to innovate fast to this new project reality and generate an offline, embedded solution.
To enable it to work quickly in an offline situation, they needed to build all the data and software into a local app that would be housed on the Kantar CAPI machine. They wanted to mirror the online solution as closely as possible so they reimplemented the software using a local server on the interviewer’s device. They created three mechanisms for transferring the interviewee’s last journey data (start / finish locations, SRN roads used and lengths travelled, etc.) back to the survey software – where questions could then be asked specifically about the SRN travelled on. Because they also stored the whole journey information in a local database, the route taken could be recalled for prompting and analysis purposes.
- The mapping is invoked through a Uniform Resource Locator (URL) and the return URL is also passed – so that control can be handed back to the survey software, along with the journey information, when the journey capture is
- The map puts the journey data onto the Windows clipboard to be picked up by the survey software.
Beacon Dodsworth were also asked to support the creation of the survey sample – by analysing the proximity of each Output Area (OA), of around 170,000 areas of equal population sizes and similar social groups in England, to each named road of the SRN (113, e.g. M23) – both in drive distance and crow-fly distance. This involved customising their base network navigation software to reduce the search space. Knowing how many people can access the SRN in a given time informs how to distribute the sample of respondents.
As a backup to the interactive map, a new set of static maps were generated which could be reproduced on paper. For consistency, the road network data came from the same sources as the journey capture software. The challenge here was to choose a suitable scale to encompass the full strategic road network but provide enough detail that the interviewee could orientate themselves on the map.
Other users of the SRN
While the SRUS measures satisfaction among drivers using the SRN, Transport Focus has undertaken research to understand levels of satisfaction among other users of the SRN (e.g. cyclists, pedestrians and horse riders). This is subtly different because users might not travel on the carriageway but alongside, or across it – possibly using a bridge or underpass. The online version of the mapping was adapted to accommodate this, with appropriate changes to the prompts. The journey information passed back reflects the user’s proximity to the SRN rather than the route along it. They also added the ability to add “hotspots” of particular concern to the interviewee.
Data used in the project
Central to this entire project was Ordnance Survey (OS) data. OS offer a Public Sector Mapping Agreement (PSMA) to public sector organisations such as Transport Focus. This allows organisations in the public sector to benefit from high-quality mapping data, free at the point of use. Under this agreement, OS supplied the following data, for use with Transport Focus:
- Detailed road network data via OS Integrated Transport Network
- Background maps as raster tile images
- Output Area data as polygon boundaries
Beacon Dodsworth also used SRN – HAPMS: a definition of the Strategic Road Network used by Highways England, matched to the underlying road network. In addition, they used postcode data from the Office of National Statistics (ONS) National Statistics Postcode Directory (NSPD).
Transport Focus officially announced the first set of quarterly findings on 7 November 2018 at the Highways UK conference. At the launch, Anthony Smith, Chief Executive of Transport Focus, called the results, “the most significant and robust picture ever of driver satisfaction on the motorways and major ‘A’ roads maintained by Highways England.”
Initial results showed that 82% of road users were satisfied with their last journey on the SRN, while 93% were satisfied with how safe they felt on Highways England’s roads. Information on permanent road signs scored well at 89% satisfaction, whereas information provided on electronic signage was lower at 83%.
The detail of these results will allow Transport Focus to provide useful, specific advice on where Highways England need to focus their resources in order to improve the SRN. An ongoing process, Transport Focus aim to survey around 9,000 people each year to provide continuous and timely feedback to Highways England.