Visualisation is a crucial tool in understanding and communicating data. Its use in transport planning is growing, but it remains a specialist activity, often reserved for larger, higher profile projects.
However, the arrival of new tools that focus on movement data make it quick and easy for anyone to visualise sensor and modelling data key to transport planning.
The use of data visualisation has exploded across a wide range of industries over the last decade, with the pace ever increasing. There has been a shift from analysing data using statistical techniques alone, as people adopt graphical representations to aid analysis and understanding.
The growth of business intelligence (BI) tools such as Tableau, Qlik View and Microsoft Power BI that provide advanced analytics and visualisation is a measure of this transformation. These tools leverage the brain’s capacity to quickly understand and interpret graphical rather than numerical representations.
Such tools are increasingly being used within transport planning, alongside traditional GIS software such as ArcGIS and MapInfo for handling geospatial data; and 3D modelling tools to generate photo realistic renderings of transport schemes. BI and GIS software provide powerful functionality to look at static data and simple representations of temporal data but they lack the capability to easily and effectively combine spatial and temporal elements into informative interactive visualisations.
What if you could easily visualise this movement data? What would be the value to a transport project if you could easily analyse the data and communicate key metrics and findings? How do trip profiles change over time? How do traffic flow, speed, journey times or pollution levels vary throughout a network over an hour, week, month, year? And what is the impact of the scheme over five, 10 or 20 years?
Visualisation helps answer these questions. It provides clarity and facilitates discussion throughout a project, providing a means for everyone involved to understand the issues.
A selection of Ito World visualisations.
The use of interactive visualisation to present large complex datasets allows the viewer to comprehend and analyse data that would otherwise be impenetrable. You can quickly spot patterns, trends and anomalies that are difficult to identify when studied using numerical analytical tools alone. This is particularly apparent when dealing with movement data that varies by both time and location; for example, you can easily view trips by purpose, origin, destination, mode of transport or any combination, understanding how they vary over time.
Interactive visualisations exploit and enhance the viewer’s cognitive capabilities rather than relying on predefined numerical approaches. When both temporal and spatial dimensions can be easily and effectively presented simultaneously, visualisation becomes valuable at all stages of a transport project.
The ongoing transition to using large complex datasets automatically generated from sensors rather than traditional surveys to feed our transport models makes it more important than ever to understand the datasets being used. With the correct tools it becomes fast and easy to visually screen and validate this input data.
Visualisation is an effective tool for the calibration and validation of models as they are built. Model outputs can be visually compared against count data. While such visual inspection doesn’t replace statistical analysis, it can greatly accelerate the calibration phase by making it easier to spot inconsistencies, making iterations faster and reducing the number required.
Similarly, interactive visualisations of model output reveal insight during the analysis of results. Many leading traffic simulation software packages include visualisation capabilities for this purpose but others lack the functionality, as do custom developed spreadsheets, R or Python models.
Effective visualisation is vital when communicating study results. Outputs from a range of analyses and models need to be communicated to stakeholders who are not necessarily experts in the use of a particular technique and are not used to looking at such outputs. Results need to be shared between sub-teams working on a project such as transport, economic and environmental teams; with project managers; project sponsors; and, in some cases, with ministers and the public.
The ability to convey complex information in a concise and understandable way is crucial for a project to progress. An effective visualisation can summarise a two hundred page report into a two minute video. It can set out the issues, and present and quantify the benefits of the solution in a way that non-experts can understand.
A key component of a successful visualisation is the ability to present different datasets in a common visual language. Consider the case of a new road scheme where a report may include historical and projected traffic data for the base case and different schemes; accident data; noise and air quality data; journey time predictions; as well as contextual information. These come from multiple sources, both measured and modelled, in a range of data formats.
The report is much easier for both the expert and non-expert audience to understand if all this information is presented in a consistent style, rather than varying according to the software package used to produce or analyse the data. The images below illustrates different datasets presented in a common visual language.
Click to expand. Image: Ito World.
Ultimately, with the right tools that focus on movement data, visualisation will be used throughout transport projects – saving time, increasing insight and delivering a better result for the end client.
Johan Herrlin is the chief executive of Ito World.This article is from the CityMetric archive: some formatting and images may not be present.