What data will it need?
Themes: Data from technology; Existing MIS data; Other data sources
A broad set of data requirements need to be considered for ITS
Having defined the platform, it is necessary to define the specific data requirements associated with the ITS systems. The application software of ITS systems is highly dependent on data, and it is also the task of many ITS applications to generate, collect, store or transfer data. The data requirements will come into a number of broad categories:
- Support data which the ITS system needs to carry out its functions (background data, configuration data, daily assignment data)
- Real-time or event/transaction-specific data which the ITS requires when it is performing a specific function. It may generate this data itself, or receive it from another device or system
- Data which the ITS system should pass to devices, both for immediate and downstream use
Any assessment of data needs must be comprehensive at the entity level. It must consider both the specific ITS systems and the broader IT systems (including administrative systems) within the entity. It must also consider ITS/IT systems in other entities with which the Operator will need to exchange data from its own ITS/IT systems. The reason for doing so is that a very many ITS applications either receive information from IT systems as input, or transfer the gathered data to IT systems for downstream processing.
It is not possible to provide a comprehensive guide to data needs for all ITS devices, applications and services in a guidance document such as this. More detailed guidance can be found websites such as the RITA unit of US DOT, or of TRANSMODEL (see Links section) . This section provides a general introduction.
Categories of Data associated with ITS systems
The data needed by and associated with ITS systems can be broadly categorised under the following headings:
- Background or platform data. This is often system-wide and includes items such as GIS/mapping, network/route descriptors, bus stop inventories and bus stop attributes. This data does not normally change, although arrangements must be made to adjust the data when required (e.g. add new route)
- Configuration data: This includes lists of devices, vehicles, known staff, and where they are normally/currently located. It may include items such as faretables. This data is 'semi-fixed' - i.e. it does not change daily, but it is subject to ongoing change over a period of time (e.g. new vehicles enter the fleet, drivers join/leave, machines are reallocated to other locations). Due to the occasional nature of change, it requires a means of update and of verification.
- Daily operational inputs: This provides the data needed for the daily operations, and includes items such as the vehicles and drivers assigned to specific pieces of work (route/duty). It may be generated manually or from applications such as staff rostering software.
- Generated/sensor data: This is data generated by or for the ITS devices during the daily operations – e.g. vehicle location data, ticket issue transaction, fault sensor alert, CCTV images.
- Real-time transfers in to ITS devices: This is real-time data which an ITS device needs in order to perform a function – e.g. in-vehicle displays and ticket machines may both need the current location data, continually updated.
- Real-time transfers out to ITS applications: This is data which processing applications need to receive in (quasi-) real-time from the ITS devices – e.g. the Operations Management program at the Control Centre needs to receive the location data from all the relevant vehicles so that the dispatchers can see the current route status; the RTPI systems needs to receive the location data to forecast arrival times at bus stops.
- Data for downstream processing and analysis/reporting: A very large amount of data is generated by the ITS devices and applications. It is transferred, stored and analysed for an extremely wide range of purposes. Analysis that is routinely performed includes performance analysis, problem identification, route planning and scheduling, fuel consumption analysis. In other cases, analysis is carried out on request – e.g. in case of incident, accident or complaint.
- Data for downstream processing and re-input: Some data is gathered, processed, and re-entered into the ITS systems - e.g. the location data from the AVL system is analysed to identify speeds and journey times (and their variances) along each section of the route. This is re-input to update the background data of the AVL system, route scheduling and RTPI forecasting applications, so they are more accurate than the original inputs which were based on estimates or surveys, and/or reflect the gradual changes on the routes over time.
Using data and materials from other locations
This is a technical task that requires expertise and experience. There is considerable scope for transferring and re-using materials from industry good practice and from other successful ITS systems. Nonetheless, it is very important that any such replication is carefully adapted to the needs of the deployment site, and is fully compatible with the Functional Specifications and the site Technical Design.