Data and Information

A pre-requisite for Road Network Operations is the collection of accurate data that defines the status of road network, the traffic conditions that prevail and information about roadway conditions and the immediate environment. (See  Planning Procedures) Data on traffic and weather conditions, incidents and other road and highway status alerts is used to provide intelligence for network operations activities, traffic control and information systems. This process of gathering data is called network monitoring, and can be undertaken by using a variety of means or a combination of them:

• Automatic Incident Detection (AID)
• traffic flow and speed sensors
• probe vehicles
• driver reports on mobile phones
• monitoring social networks (crowd sourcing)
• closed circuit television (CCTV)
• information provided by other parties such as vehicle fleet operators, road maintenance teams or the emergency services

The extent and reliability of monitoring directly affects the amount of information available to plan operational activities and, in turn, the degree of management and control that is possible. It also determines the quality of information that is available to travellers and road users. (See Network Monitoring)

The Network Information Supply Chain

A number of steps are involved in the organisation of data processing and information supply. Together they form an information supply chain.

Data Acquisition

The first step is to acquire data about the status of the road network and the traffic using it, as well as other transport modes that connect with it. This data can come from a wide variety of sources including probe vehicles and roadway sensors such as inductive loops and microwave sensors, Closed Circuit TV (CCTV), webcams, video image processing, toll tag readers. It can be augmented with other information gathered from crowd sourcing and journalistic sources. Data mining techniques are applied to historical data to gain further insight into traffic operations and to provide predictive information on network conditions. (See Traffic & Status Monitoring)

Data Processing

Once the data is collected, the next step is to process it in ways that will yield useful information. This covers a number of basic functions:

• proper formatting of the data
• cleaning-up data that is unreliable or irrelevant
• adding an appropriate time stamp and location referencing
• coding, using data dictionaries, that ensure that the data can be made available for data processing
• data fusion, involving the integration of data from different sources

Information management

The third step relates to the data analysis. This requires an appreciation of contextual relevance, processing of content to produce information according to user needs and preferences – including formatting the data for service. Data needs to cover the geographical area of interest and be checked for timeliness. Key issues are:

• data exchange between the different systems and applications
• quality control to check the data is collected and processed accurately

To provide predictive information, various time series analysis, data mining, mathematical modelling and Artificial Intelligence (AI) methods are used (See Data Aggregation and Analysis).

Transmission and distribution

Various methods are used to disseminate the data that has been collected, processed and analysed. A variety of transmission media are available. For example, incident warnings and travel information is provided via many dissemination media, including data subscription services, travel news broadcasts, Highway Advisory Radio (HAR), roadside Variable Message Signs (VMS), internet websites and social media such as Facebook and Twitter. The security and integrity of transmission needs to be checked and maintained at all times. (See  Traveller Services)

End-user interfaces

Information needs to be presented appropriately in response to user needs and the context of use. Good design of the user interface is essential. In traffic control centres, data may be displayed alongside CCTV camera images on a video wall or on-screen at operators’ work stations. Other stakeholders and the travelling public will use a range of devices to access information – such as desktop, laptop and tablet computers, mobile devices and smartphones, in-vehicle displays, public information points and kiosks. (See User Interfaces)

Supply and ownership issues

Issues may arise related to data ownership and intellectual property in respect to the use of public sector data versus commercial and proprietary data, information branding, value-capture, revenue and payment. (See Legal and Regulatory Issues)