Network Monitoring Activities

The main objectives of road network monitoring can be summarised as follows:

• keep track of traffic volumes, service levels, incidents and road environmental conditions
• support road control room operators in making decisions on how to better operate the network
• monitor and evaluate network operations functions
• accumulate and archive data for off-line analysis

Each objective is realised through various solutions, including the application of ITS technolgies.

Network monitoring is expensive. When considering the provision of monitoring systems it is important to establish the key purpose of collecting specific information and to design systems accordingly. Depending on the local context, information may be needed on a variety of factors – such as traffic and weather conditions, incidents and other road and highway status alerts – in order to provide intelligence for network operations activities, traffic control and information systems. Other examples are:

• vehicle speeds – especially for incident detection and for speed control where traffic is heavy – or for enforcement where road safety is at risk from excessive speeds
• traffic flows – needed for local traffic control at signalised intersections and across a network to provide information on travel demand
• vehicle counts – often classified by different types of vehicles for traffic management purposes
• lane occupancy – to provide an appreciation of the level of service available to road-users on expressways and motorways
• point-to-point journey times – for route planning and as an important source of real-time information for road-users
• journey time reliability – to measure of the overall level of service offered to road users and to assess the effectiveness of network operations
• environmental characteristics – to monitor weather and road surface conditions and atmospheric pollution

Events On the Network

Managing events on the road network in real-time requires the means to detect and rapidly assess any situation that is potentially problematic as soon as it arises, with reliable procedures for a quick and suitable response.

To carry out these tasks, the desk operators must:

• have ready access to the necessary network and related information (See Basic Info-structure and Data and Information)
• be able to rely on the organisations that will be involved in event response (See  Incident Response Planning)
• have a clear vision of what must be done, on their own initiative or as part of an organisation set in motion elsewhere (See Traffic Incidents)
• know and maintain current response procedures (See Planning Procedures)
• periodically update their analysis, referring to indicators monitoring the event and the consequences they have recorded (See Monitoring Technologies)
• forward their analysis and compare it with those of the other players

Analysis of the situation must have regard to: 

• context, including site details, weather and environmental factors, sensitive points, traffic, stakeholders and players
• a search for complementary information (including cross-checks of all information received)
• identification of potential aggravating factors.

This task demands major efforts to develop systems that capitalise on and disseminate past experience. Crucially it requires good staff coordination to avoid instances where staff work at cross-purposes during an emergency.

All the organisations and agencies that have a part to play in the network operation will have an interest in network monitoring activities. In planning, designing and allocating resources to the network monitoring system the equipment, information systems and operational procedures need to be specified in line with the coordination arrangements. In particular, when multiple partners are involved at the operations centre a flow of command needs to be established in order to ensure smooth implementation. (See Operating Agreements)

Agreement on operational procedures is especially important when the data being monitored are used for enforcement purposes. Usually, network operators do not have the power to actually catch or rectify the offending situation even when it is necessary to do so in order to ensure a smooth operation. Close planning and cooperation with enforcement agencies are critical. (See Enforcement)