Road Network Operations
& Intelligent Transport Systems
A guide for practitioners!
Road Network Operations
& Intelligent Transport Systems
A guide for practitioners!
ITS is not only about the use of telecommunications and information processing in road transport operations. Many of the challenges that accompany the introduction of ITS are not about technology but about different ways of working – especially different organisations working together in new ways. There is now a large body of ITS ‘know-how’ that draws on the practical experience of substantial numbers of ITS projects and case studies.
To properly understand how ITS works, there are a number of issues to take into account:
For ITS to work, a number of technologies are needed.
Collecting accurate information about the status of the transport system is a pre-requisite for almost all ITS applications. The problem needs to be identified before coming up with a solution. The front-line group of enabling technologies are those used for collecting real-time traffic information. Some of these are infrastructure-based and others are vehicle-based.
Infrastructure-based detection technologies include:
Vehicle-based detection technologies include:
(See Data and Information)
Telecommunications may be compared with the nervous system in the human body. Communication networks link the different components of an ITS system together, allowing for the exchange of information and for the implementation of the different traffic management and control strategies. They also link the traveller to the system allowing for the dissemination of useful information. (See Telecommunications)
To be useful, the real-time traffic and environmental data collected from the field must be processed, fused together with different sources and analysed. Data processing and computing technologies refer to the set of computer hardware and software that is needed to make sense out of the data, and convert the data into information that can support decision-making. (See Basic Info-structure)
Effective communication with travellers is an essential component of several, if not all, ITS applications. ITS uses several traffic information dissemination devices to keep travellers informed about current as well as expected travel conditions. These devices include Dynamic Message Signs (DMS), highway advisory radio (HAR), cable TV, traveller information websites, social media (Facebook, Twitter) and the internet, dedicated phone systems, and in-vehicle display devices. (See User Interfaces)
The most common technology currently used for location and navigation are satellite navigation systems for location determination (latitude, longitude, and elevation). These triangulate ground position based on satellites signals – and are known as Global Navigation and Satellite Systems (GNSS). The most well-known is the USA’s military Global Positioning System (GPS). The European Union is developing a compatible civilian system, GALILEO – aimed at providing higher availability and improved positioning accuracy. (See Navigation and Positioning)
Light Detection and Ranging (LIDAR), a remote sensing technology, can be used to generate three-dimensional information about different locations and their surface characteristics. LIDAR, either airborne, mobile or terrestrial, has been used in transport for various tasks, such as surveying, highway design and highway safety. With accurate mapping and positioning of roadway infrastructure, LIDAR can support various ITS applications – such as real-time roadway-weather monitoring and real-time evacuation support during emergencies.
Control technologies constitute another group of enabling technologies for ITS applications. They can be divided into two broad categories:
One of the most widely deployed ITS applications is in the area of electronic payment, which:
In terms of hardware, the most common technologies for electronic payment are: smart cards, transponders (such as a toll tag) and more recently, smart phones. (See Electronic Payment)
This group of ITS enabling technologies includes those designed to support Archived Data Management Systems (ADMS) – or what are sometimes also known as ITS Data Warehouses. ADMS offers an opportunity to take full advantage of the data collected by ITS devices in improving transport operations, planning and decision-making – often at a minimal additional cost. The technologies supporting ADMS are designed to archive, bring together (or fuse), organise and analyse ITS data from different sources and can support a wide range of useful ‘intelligent’ applications. (See Data Management and Archiving)
A feature of integrated systems that are designed to serve the mobility needs of people and goods distributed spatially over a large geographic area, almost always requires the collaboration of several stakeholders. (See Stakeholders)
Any ITS deployment generally involves a range of organisations. It is often the case that a champion or client agency will take the lead. This could be a road authority or a department of transport, local government , a public transport operations agency – or a coalition representing all these parties. (See Inter-agency Working)
One method of ITS procurement will involve a specialist consulting firm acquiring a wide range of ITS equipment and technologies from a number of vendors and manufacturers of ITS technologies. The consulting firm would typically act as a system integrator bringing together all the technologies and components so they work as a truly integrated system. (See Managing ITS Implementation)
For ITS to be effective, its different components have to work together as one integrated system. The components have to be able to communicate with one another, and need shared data dictionaries and communications protocols. This underscores the importance of adopting a systems engineering approach to the design, deployment and management of ITS projects. (See Systems Engineering)
A systems approach will consider the context of ITS deployment and how all the component systems fits together. A fundamental aspect of the approach is that User Requirements are defined at the start – and taken into account in the design and development of the system. It is different to a technology led approach. It also explores the various system interfaces, the data that needs to be exchanged, the equipment and communication standards – and the building blocks that need to be in place for effective operations. A systems approach also considers how ITS would fit within the larger regional transport system, and investigates how to maximise the benefits from the system. The approach considers not just the technical challenges, but the institutional ones as well – which are key to integration and collaboration. (See ITS Architecture)
Human factors are of great importance to ITS deployment and effectiveness – from the perspective of infrastructure, operations and vehicles. For vehicles, it is important to ensure that ITS applications do not distract drivers from their primary driving task – or overload them with information. This is particularly the case with Advanced Driver Assistance Systems (ADAS) – which continue to mature and increase in sophistication. Another important area is smart phone usage and “infotainment” applications. Many studies have shown the dangers of using a phone while driving (and worse still – texting while driving), and many countries have issued laws banning the use of cell phones and similar devices whilst driving.
The likely response of drivers and travellers to an ITS system recommendation is another key area. An ITS system may recommend to drivers, a certain speed or a specific route to arrive at their destination – but there is no guarantee that the driver will follow the system’s recommendation. Building trust in ITS systems is critical for public acceptance.
In terms of future development of ADAS, human-machine interaction is critical in ensuring that the driver interacts safely with the vehicle and the technology on board. The prospect of vehicles with various levels of automation – which may soon lead to partially or fully autonomous (self-driving) vehicles – makes this a more urgent issue. (See Human Factors)
ITS is all about acquiring data and information, the exchange of information, the processing of information, the use of information to support decisions – and the dissemination of information to travellers and other end-users.
It shows ITS using detection and monitoring technologies to collect data in real-time – about the transport system and other external factors (such as the weather). The ITS then uses its communication network to exchange this information between different traffic centres, different agencies, and different regions. The information gathered is then processed and analysed to understand how the transport system is operating – and to identify “optimal” management and control strategies aimed at improving system performance. The information is also disseminated to a wide range of ITS stakeholders – such as traveller information to the transport system users. (See Data and Information)
ITS applications include the information infrastructure that supports the collection, archiving, processing and distribution of a wide variety of data – for example about travel demand, traffic volumes and journey patterns.
Data is collected continuously by different ITS tools with different characteristics – such as quantity, frequency, timing (real-time, near real-time or historical), and reliability. By systematically validating, storing, archiving and fusing data from different sources, the compiled data can be mined and analysed to gain useful insights into how to best plan, operate and manage the transport system.
ITS data provides a very important resource for calculating performance measures to assess the quality of service provided by the road network – and any associated ITS applications, such as automatic incident detection.
Performance measurement is a topic that has received increased attention in recent years. Growth in the data sources for ITS – such as social media, GPS and communication-enabled connected vehicles – are coupled with changing security and privacy concerns. The impact on the planning, design and evaluation of ITS information infrastructure will be in the forefront of any ITS deployment consideration. (See Performance Measures)
The development, deployment and operation of ITS requires coordination and collaboration among a wide range of stakeholders. (See Stakeholders) Those stakeholders typically include (amongst many others):
The deployment of ITS also needs a “champion” – or a strong leader – who believes in the vision and can inspire others. The first step in any ITS planning initiative is to identify the key stakeholders and build local partnerships (with memoranda of understanding if required) to allow for combined action and joint problem-solving. (See Inter-agency Working)
In ITS the term ‘architecture’ describes a structured framework within which the components of ITS systems are brought together so that the whole can function efficiently – much as construction products and services in a building.
ITS architecture is essential for the planning and design of an ITS deployment – that will meet the needs and requirements of users. An understanding of ITS architecture helps to define how the component systems need to interact with each other – and will clarify the roles of individual stakeholders in the implementation process. The analysis should be firmly based on an assessment of the functions and system performance that are necessary to meet user needs. (See What is ITS Architecture?)
An ITS architecture can provide many benefits to a region as it begins to develop and deploy ITS-based systems and services. A properly designed ITS architecture will:
The concept of interoperability is very important in ITS. For example:
To facilitate this kind of interoperability, an ITS architecture (where one has been adopted) will identify the system interfaces or information flows that need to be harmonised – and, if possible, standardised. The ITS architecture is an important tool for the success of this process, since it describes how the different components of a system should interact with one another. (See ITS Architecture)
The real advantage of interoperability becomes more obvious when the different ITS systems share and exchange data and information with each other. For example:
The process of linking the different components of a system is typically referred to as “system integration.” This becomes a major issue as more and more ITS components are deployed. (See Systems Engineering)
Within the context of ITS, the term “user services” is used to describe what ITS does for the users of the transport system – including travellers, transport operators, planning organisations, road authorities, government ministries and departments of transport. The US National Architecture, for example, currently defines 33 ITS user services, grouped into eight major user services bundles as shown here: http://www.iteris.com/itsarch/html/user/userserv.htm.
ITS user services share a number of basic characteristics.
In the US National Architecture, the different user services have been arranged or grouped into eight bundles, which define focus areas for ITS applications: (See Using the US Architecture)
The European Frame architecture adopts a comparable approach based on user needs that are grouped into nine broad areas:
The Frame Architecture also provides for links to other modes of transport – for example, to provide travellers with multi-modal travel information, to manage mixed mode at-grade crossings (where a road or highway meet at a level crossing) and to respond to incidents that take place on other modes. (See. Using the FRAME Architecture)
Evaluation studies and operational tests have shown that ITS applications have provided significant benefits across surface transport modes. In the road transport sector, ITS aims to improve the performance of roads and highways by using real-time and historic information on the status of roads and traffic. ITS applications can enable better road transport operations – more safely, efficiently and in a more sustainable way, with better inter-modal connections. Benefits include safety, journey time, travel reliability, energy consumption, emissions and customer satisfaction. (See Benefits of ITS)
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