The use of technology to manage transport systems, and to improve their efficiency and safety, has a long history that predates the first use of the term “ITS” in the 1990s.
Among the first examples of technology applied to road transport were urban traffic signal control systems – with increasing levels of sophistication over time (in terms of sensing vehicle presence and control logic). Their purpose was to control traffic at road intersections to improve traffic flow and safety. Other early ITS applications were for motorway incident detection and improving the information available for travellers – with real-time traffic alerts and roadside Variable Message Signs. (See Traffic Control)
In the 1990s, there was increased recognition of the negative impacts of road transport (such as congestion, accidents and pollution) and the search began for solutions to the challenges that facing large, congested, metropolitan areas. The traditional solution of adding capacity by improving the road infrastructure was often no longer viable – for example, because of environmental concerns or the unavailability of space. These factors combined to motivate transport professionals to investigate the potential for utilising advanced technologies – such as sensing, communications and computing – to improve the performance of road networks.
ITS deployment is now almost ubiquitous in developed countries and has begun to take root in many emerging economies as well. The range of potential applications for ITS, has dramatically increased. Whereas initially the focus was on stand-alone applications, there are now examples of truly integrated systems – solutions that look at the transport system as an integrated whole – for example, integrated multimodal ticketing. (See Multiuse/Intermodal Ticketing)
The early years of ITS were championed by a handful of countries – including the United States, Canada, a number of European countries, Japan and Australia. In the USA, for example, several transport reauthorisation bills – from the 1991 Intermodal Surface Transportation Efficiency Act (or ISTEA) onwards, encouraged the deployment of ITS and the search for advanced technology applications in transport. A number of Field Operational Tests (FOT) were also undertaken – designed to test the feasibility of implementing the technology-based solutions, as well as provide information on their likely costs and benefits.
A decade or so ago the means for disseminating information to travellers were rather limited (such as Dynamic Variable Message Signs, Highway Advisory Radio, Television, and phone systems). Today, with the almost universal market penetration of smart phones and other mobile devices, it is much easier to reach travellers with the correct information. (See Traveller Services)
Recent years have witnessed a renewed and increased interest in the topic of connected and autonomous (self-driving) vehicles – which can be regarded as the latest phase in the evolution of ITS. Third and fourth generation digital mobile telecommunications have enabled higher levels of connectivity between vehicles and the infrastructure, coupled with greater automation within vehicles. This may radically change the way that motor vehicles are driven and the way that road traffic is managed. (See Connected Vehicles)
ITS service Areas
The principal applications of ITS – that contribute to road network operations are:
The table below illustrates the eight main ITS service areas – and provides examples of service applications in those areas.
| Service Area | ITS Related Applications | Operational Goal |
|---|---|---|
|
Traffic management |
Incident management; traffic control. |
Manage and control traffic on roadways to optimize its operation. |
|
Traveller information |
Pre-trip traveller information, en-route traveller information. |
Provide trip related information to travellers before, or during their trips |
|
Public transport |
Transit vehicle tracking; transit security. |
Improve public transport services to encourage their use |
|
Commercial vehicle operations |
Commercial vehicle administrative processes, Automated roadside safety inspection, hazardous material incident response |
Improve public sector fleet management; improve public sector administration of commercial vehicle operations |
|
Vehicle safety |
Vision enhancement, longitudinal and lateral crash avoidance; intersection crash avoidance. |
Improve the safety of the transport system by supplementing drivers’ abilities to maintain alertness and control of the vehicle, and enhancing crash avoidance capabilities of vehicles |
|
Construction and maintenance operations |
Fleet management; work zone management. |
Improve management of vehicles associated with construction and maintenance; managing work zones, managing roadways for supporting construction and maintenance |
|
Emergency management |
Emergency notification; emergency vehicle management. |
Support emergency management functions with faster identification of emergencies and response |
|
Archived Data Management |
Data depository |
Collect and compile data for traffic prediction, system performance monitoring and policy analysis |
ITS-based services share some general characteristics:
Time is a critical element in ITS services which often make use of real-time or near real-time data. The time frame for collecting and processing live data is limited, although historical data is frequently used. For example, traffic information – such as travel time, link speed and information about incidents blocking lanes – is only useful to travellers if it is made available in real-time or predicted near-future time. (See Traveller Services)
Many ITS services can enhance the capacity of existing road infrastructure by means of operational improvements that avoid the need for expenditure on major improvements – such as constructing new roads or adding additional lanes. For example, on congested motorways – managed lanes and speed control can benefit safety leading to fewer traffic incidents and improved traffic throughput. Strategic re-routing can divert traffic from congested roads to less congested roads at certain times of the day. Traffic signals can be made to be adaptive to real-time traffic demands to improve efficiency and capacity of signalized intersections.
Data collected through ITS – such as traffic speed, traffic volume and vehicle tracking data – can be used for real-time decision support for individual travellers, road network operators and vehicle fleet managers. Data collected through ITS can also be used in algorithms and models that assess current and future network conditions – which provide decision support. Data collected through ITS can also be archived until needed for planning purposes.
ITS services are most valuable and effective in unfavourable conditions – such as during an incident, evacuation, congestion or disruption of services. For example, an incident may cause significant delays and contribute to secondary traffic accidents. ITS services – such as quick detection of an incident, faster response and incident scene management – may reduce the duration of an incident, which will contribute to reductions in traffic delays and a lower probability of secondary accidents.
ITS provides an opportunity to enhance reliability and safety of a trip. ITS services – such as satellite navigation, incident management and adaptive traffic signal control – can reduce delays and improve the reliability of a trip. Similarly, ITS services geared towards safety – such as speed warning and enforcement and intersection collision avoidance – can decrease the probability of an accident.
ITS services have been developed for more than one mode of transport – and can target different types of vehicle. For example, roadway network monitoring services keep track of passenger cars, buses, emergency vehicles and commercial vehicles. ITS services can also determine priority routing for specific vehicle types – for example, buses and coaches can be prioritised with a green light at traffic signals along a corridor. Similarly, signal pre-emption technology can allow emergency vehicles to receive -of-way through an intersection by directly communicating with the traffic signal control equipment.
Miles J.C. (2014) Intelligent Transport Systems: Overview and Structure (History, Applications, and Architectures). Automotive Encyclopedia ISBN: 9781118354179 Wiley on-line Library.
Table of contents can be accessed on-line at: http://onlinelibrary.wiley.com/book/10.1002/9781118354179/toc
A common feature of ITS – when applied to traffic and road network management – is the use of real-time, conventional and historic data sources to produce information on the existing and future status of the road transport system. ITS applications play an important part in the way road networks are managed to improve the efficiency and reliability of transport operations and reduce negative environmental and energy consumption impacts. (See Traffic Management)
Examples of ITS applications in road network operations are:
Traffic and road network management applications aimed at improving road transport efficiency includes electronic payment to remove the need for vehicles to come to halt before paying a road toll and to simplify fare payment for public transport. (See Case Study: Traffic Management, Travel Information and Bridge Tolling at “The Ǿresund Link”)
Electronic tolling systems also provide the flexibility needed to implement innovative road pricing and congestion charge schemes.
The principal ITS applications that support traffic and road network management include:
Traffic control aims to manage and control the movement of traffic on roads to optimise the use of existing road capacity. ITS applications include:
The implementation of effective traffic control strategies requires timely and accurate traffic information. The better the data, the more effective the control strategies that can be implemented. Information is gathered from various sources – such as detector loops in the road pavement, roadside and overhead sensors and analysis of digital camera images. The data can be combined and used to decide upon the best (or optimal) course of action for managing traffic on the network. (See Traffic Control)
Traffic control is one of the most basic building blocks of an intelligent road transport system, since it requires detection, control, communications and support systems – that are fundamental to the operation of several other ITS services. Traffic control and traffic operations centres (TCCs and TOCs), responsible for these functions, now exist all over the world. (See Traffic Control Centres)
ITS plays a significant role in improving incident management, particularly on highways, motorways and other high speed roads. This is because it uses vehicle sensors (such as inductive, buried, loops, radar and CCTV cameras), data processing and communications technologies to quickly detect and verify an incident. Sophisticated decision support systems then help traffic managers to decide how to best respond to any given incident. Using ITS in this way can improve safety and network efficiency, saving lives and money. (See Traffic Incidents)
One of the application areas where ITS has achieved great success is in the area of electronic payment. Among the prime examples of electronic payment are Electronic Toll Collection (ETC) systems such as the EZPass System in the USA or the European Electronic Toll Service. These systems allow drivers to pay road tolls without stopping or slowing down their travel speed – minimising delays and improving air quality in the vicinity of toll plazas.
ETC systems can take various forms such as:
These systems can impose different tolls for different classes of vehicles, and can provide for the automatic enforcement of violations. Other examples include integrated payment systems – designed to allow a traveller to pay for different services (for example driving on a toll road, paying for parking, paying for transit) using the same medium or device (See Electronic Payment).
ITS can be applied to implement strategies aimed at increasing the frequency of Multiple-Occupancy Vehicles (MOVs) and promoting the use of High-Occupancy Vehicle lanes (HOVs). ITS can help make the operation of HOV lanes more effective and adaptive to changing traffic conditions – by adjusting vehicle occupancy requirements at different times of day, based upon current traffic and congestion levels. ITS also can help implement congestion pricing strategies – where toll charges are adjusted to influence demand. For example, tolls can be increased during peak hours in urban areas or in the vicinity of environmentally sensitive tourist attractions in rural areas. (See Demand Management)
ITS can be applied to better manage the allocation and price of parking spaces. This helps improve the travel experience of drivers by providing real-time information on spaces in parking lots. ITS-based parking information systems can be integrated with city-wide traffic management and control – to minimise parking search times and optimise traffic management overall. Electronic toll tags can also be used as a means of controlling access to a controlled parking area. (See Access Control)
ITS can help improve the environmental sustainability of road transport. Some ITS applications use environmental sensors to collect information about exhaust emissions from vehicles at a certain location, or over a wide area. The information can then be used to intelligently divert traffic away from areas where air quality has fallen below an acceptable threshold – or by not letting vehicles access these environmentally sensitive areas. The information can also provide valuable input to the development of air quality improvement strategies – and to alert vehicles’ operators if their vehicles are not compliant with adopted emissions standards. ITS can also be used to manage congestion and reduce delay – which has beneficial impacts on emissions and air quality. (See Driver Support)
The purpose of a highway-rail intersection ITS application, is to provide improved warning and safety control devices where a railway (railroad) crosses a road or highway at a level crossing (an “at-grade” crossing). On the approach roads to the crossing, any signalised intersections can be connected to the control and warning devices at the highway-rail intersection (HRI), so that signals can be coordinated to manage queuing and divert traffic. The technology can also monitor the “health” of HRI equipment – and report any detected malfunctioning. (See Enforcement)
ITS system and service applications have an important role to play in emergency situations:
Emergency notification and personal security applications include systems that:
The European eCall and American OnStar systems are good examples:
Emergency vehicle management focuses on applications intended to reduce the time from the receipt of an emergency notification to the arrival of the emergency vehicle at the scene of the incident. This is accomplished through:
Traveller information systems is an application area that has seen numerous ITS developments and heavy investment. (See Traveller Services)
There are five of the leading applications:
The goal of pre-trip travel information is to provide travellers with information about the status of the transport network before they begin their trip. The information provided can be limited to road or multimodal transport – and can include:
In the early years of ITS, travellers were able to access this information at home or work (via a computer or a telephone system) and at places generating traffic (for example, a shopping mall – via a touch-screen kiosk). Nowadays, with the proliferation of smart phones and mobile devices connected to the internet, travellers can access travel information anytime, anywhere. More advanced versions of these systems can provide users with predictive travel conditions, as well as help with trip planning. (See Pre-trip Information)
En-Route driver information is aimed at providing drivers with travel-related information after they start their trip – during the journey. Traditionally, this has been achieved by means of Variable Message Signs (VMS), radio broadcasts and Highway Advisory Radio (HAR). More recently with the widespread introduction of smart phones and mobile devices – and with the interest in developing Connected Vehicles – more effective means are available to provide travel information and to personalise it for the traveller specific to the journey and locations.
The development of Connected Vehicles that will be able to communicate with the infrastructure as well as with other vehicles, will allow greater opportunity for the delivery of advisory and warning messages to drivers (for example, warning motorists of unsafe conditions such as sharp curves, wet pavements, icy conditions – and alerting motorists if they exceed the safe speed limit and alerting drivers to unsafe weather conditions.) (See En-route Information and Driver Support)
The widespread use of GPS navigation devices provides drivers with detailed turn-by-turn instructions on how to get to their destinations. These directions traditionally relied on static information – for example historic travel times for different road segments, held in a navigation database. More sophisticated guidance systems are dynamic – with directions responding to changing traffic conditions based on real-time information about traffic speeds and incident locations. The digital maps that support these device need to be kept up-to-date – for example, by downloading updates on new road links and traffic restrictions.
Route guidance is now widely available through in-vehicle systems, portable devices and smartphone handsets. The benefits include reduced travel delays arising from navigational errors and lower stress levels for drivers, especially when driving in an unfamiliar area. Problems can arise for local communities when a product – intended for the general motorist – is used by drivers of large or heavy vehicles and the recommended route is a road unsuitable for those vehicles. (See Navigation and Positioning)
Ride-matching and reservation is aimed at encouraging carpooling by providing real-time matching of the preferences and demands of users with providers – and by serving as a clearinghouse for financial transactions. A traveller can call a service centre and provide it with information about the desired trip origin, destination, and time. In return, the traveller will receive feedback on a number of ridesharing options from which to choose. (See Ride Sharing / Matching)
Traveller service information is intended to provide travellers with “yellow-pages” information. This may include information on the location of services such as food, lodging, gas stations, hospitals, police stations – as well as information on the location of points of tourist attractions. Examples of these applications are already included in many GPS navigation devices and smart phone apps. (See Location Based Services)
ITS is widely deployed to improve the level of service offered by public transport – to make buses, coaches, metros, trams and trains more convenient and encourage their greater use as a means of transport. (See Passenger Transport)
Four examples of such applications are:
Public transport management applications use advanced communications and information systems to collect data to improve the:
Real-time data collected from vehicle tracking and location systems can be used to ensure schedule adherence – and to implement corrective actions when a particular vehicle is running behind schedule. Real-time information applications can also help facilitate passengers’ transfers at connecting stations. Off-line, the data collected can be analysed and used to revise schedules, to better plan routes, to satisfy contract reporting requirements, and to improve customer information systems. (See Operations & Fleet Management)
En-route information applications are intended to provide public transport travellers with information after their trips have started. Among the key pieces of information which are typically provided are:
Various information dissemination devices could be used including signs and kiosks at bus stops, internet websites that can be accessed via smart phones and mobile devices, and various types of smart phone apps. (See Information Dissemination)
Personalised Public Transport (PPT) is based on the idea of using flexibly-routed vehicles to offer more convenient services to travellers – in some cases door-to-door. There are two main types of PPT:
Ideally, this type of application will offer journey reservations – and vehicle assignment and scheduling to be developed in real-time. (See Dynamic Routing / Scheduling)
Video: Good News tests: Kutsuplus service – personalised public transport
Public transport security ITS applications are aimed at improving the security of public transport users, operators and support staff. This can be achieved by integrating vehicle location technologies and monitoring systems to provide a warning and response system to deal with security-related incidents. For example, transport stations and terminals, parking lots, bus stops and the inside of transport vehicles can be monitored with CCTV with image processing for surveillance – so that an alarm is triggered, either manually or automatically, by an “at-risk” event. Critical infrastructure, such as bridges, tunnels, rail track, can also monitored in this way as part of a public transport security strategy. (See Network Security)
ITS has been applied to improving the efficiency and safety of commercial vehicles. (See Freight and Commercial Services) There are two broad areas of applications:
Specific examples include:
Electronic clearance is designed to allow compliant commercial vehicles to continue past checkpoints at mainline speeds. As a vehicle approaches a checkpoint, communications between the vehicle and the inspection station take place – often by means of a dedicated short-range wireless link – allowing the authorities to check relevant information, such as the vehicle’s credentials, weight, safety status and cargo. This system allows enforcement personnel to select potentially unsafe vehicles for inspection, while permitting safe vehicles to bypass the commercial vehicle checkpoint. (See Credential Checking)
As a complement to commercial vehicle electronic clearance, automated roadside safety inspection ITS applications use automated inspection capabilities to facilitate safety checks with greater speed and accuracy during a safety inspection at a vehicle inspection site. This helps reduce the amount of time spent by the vehicle examiners inspecting vehicles, whilst also providing more reliable data on the safety status of the vehicle. (See Safety Information Exchange)
Among the many ITS automotive engineering applications are systems that monitor the safety condition of a vehicle and cargo as well as the driver – without the need for the vehicle to slow down. The monitoring capabilities may include:
Safety warnings are provided to drivers and can be made available to vehicle fleet managers or controllers and to roadside enforcement personnel. (See Safety)
ITS applications can smooth the administrative processes required of commercial fleet operators by government or regulatory bodies. They may allow the automatic purchase of credentials (such as a port permit or other selective access toll) and include automated reporting of mileage and fuel use. This saves the operator time and money. (See Enforcement)
ITS has a part to play in the response to incidents involving hazardous materials (HAZMAT). Law enforcement and HAZMAT response personnel can be provided with timely, accurate information on cargo contents at the scene of an accident – so they know exactly how to handle the materials involved in an appropriate way. Emergency responders can be provided with access to this information – either through remote access to the relevant databases, or, in real-time, through the use of readers that communicate with the HAZMAT vehicle’s on-board transponder. (See Emergency Response)
ITS applications provide real-time communications between drivers, dispatchers and intermodal transport providers for the purposes of vehicle location identification, dispatching, and tracking – to help optimise freight operations and vehicle utilisation. (See Operations & Fleet Management)
A number of ITS developments in the automotive sector are focused on improving the safety of the road transport system by complementing, or enhancing, drivers’ abilities to maintain alert and in control of the vehicle – and improving the accident avoidance performance of vehicles. A major motivation in their development is recognition of driver error as a major factor in the majority of car accidents. Developments in this area are moving towards the concept of self-driving cars and automated vehicle-highway systems. Examples of this type of safety-related ITS applications include: (See Driver Support)
The automotive industry has been working on a variety of collision avoidance systems that are either already in production or close to market. (See Warning and Control) These systems include:
These systems monitor the separation distance between vehicles and warn drivers when sensors detect another vehicle that may be dangerously close. If the driver does not react appropriately, automatic vehicle control actions may be initiated. Examples of these systems are already installed in the vehicles of some automotive manufacturers, such as Mercedes and Volvo.
Advanced Emergency Braking Systems (AEBS) detect the possibility of a collision with the vehicle ahead and warn the driver – using visual, audio or tactile feedback. If the driver takes no action, the system automatically applies the vehicle's brakes. At lower speeds AEBS acts to prevent a crash – at higher speeds it will reduce the severity.
Adaptive Cruise Control (ACC) tracks the vehicle in front, and automatically maintains a desired minimum distance (or time headway) from that vehicle. So long as this minimum distance is maintained, the vehicle will travel at the set speed. If the separation distance falls below this minimum value, the ACC system adjusts the vehicle’s speed to regain the minimum headway (in time or distance).
These systems detect slow moving or stationary objects and pedestrians that are in the path of a vehicle that is reversing – and warn the driver accordingly. Detecting these objects requires the use of relatively short-range sensors on-board the vehicles, such as a rear-view camera. Examples of these systems can be found fitted to many of today’s vehicle models.
Lane departure systems aim to help drivers avoid accidents that could result when a vehicle leaves its own travel lane and strays into the path of a vehicle in another lane. This is achieved by warning drivers and/or assuming temporary control of an at-risk vehicle. Among the most well-known of these systems are:
ITS technology has been tested in applications that will avoid, or to decrease the severity of, collisions at intersections. These systems track the position and status of vehicles within a defined area on approach to an intersection through the use of vehicle-to-vehicle communications and/or vehicle-to-infrastructure communications. If a potentially dangerous situation is detected that is likely to lead to a collision warning messages are delivered to the driver – for example, in cases where a vehicle fails to stop at a red light or attempts to make a turning manoeuvre in the absence of an adequate gap.
ITS applications have been developed to help eliminate and/or reduce the severity of accidents that result from poor visibility – such as night driving, heavy rain or foggy conditions. These systems include in-vehicle sensors that can capture images of the driving environment and display them graphically to the driver, for example through a head-up display. One example that illustrates the concept is the Driver Assistance System for Snowploughs developed by the University of Minnesota http://www.lrrb.org/media/reports/200313.pdf).
The goal of safety readiness ITS applications is to eliminate and/or reduce the number of collisions caused by impaired drivers (though tiredness, alcohol or drugs), a failure of vehicles’ components, or any degraded infrastructure conditions that could affect the safety of the vehicle. Systems are available that monitor the performance of the driver – and either warn or assume temporary control of the vehicle if a driver’s performance is impaired. Other systems monitor the performance of critical components of a vehicle (such as the braking system), and warn drivers of their imminent failure. There are also systems that can monitor the roadway and provide warnings to the driver of unsafe conditions – such as loss of tire traction on wet or icy road surfaces. (See Policing/Enforcement and Warning Systems)
Pre-crash restraint ITS applications anticipate an imminent collision and activate the appropriate passenger safety systems prior to the actual impact. For example, sensors are available to detect the rapid closing of distance between the vehicle and an obstacle. On detection, the system attempts to reduce the danger of the impact of the collision by settings restraints to absorb or dissipate the force of the impact – such as triggering an airbag. (See Partially Automated Driving)
A long-term goal of vehicle safety systems is a fully automated highway-vehicle system (AHVS) – where specially equipped vehicles travel, under fully automated control, along dedicated highway lanes – or where a self-driving vehicle pilots itself through mixed traffic. The AHVS concept has the potential to significantly improve the safety, as well as the efficiency, of highway travel by reducing the number and severity of crashes, decreasing congestion, and reducing vehicle emissions and fuel consumption. (See Automated Highways and New Applications)
The safety risks associated with AHVS operations need to be analysed carefully so that the risk of mal-function is minimised. Many automotive manufacturers are currently involved in significant research and demonstration projects aimed at making autonomous (or self-driving) cars, a reality. A number of countries are preparing to test the readiness of driverless cars. Nissan, for example, has promised the production of autonomous cars by 2020 – and Google has sponsored the development of a self-driving car. Initiatives from public and private enterprises may help accelerate the deployment of self-driving cars. An example is here: http://www.autoblog.com/2013/08/27/nissan-promising-autonomous-car-production-by-2020/ (See Warning & Control)
ITS has a lot to offer in terms of supporting and facilitating the maintenance and management of highway infrastructure, winter maintenance operations, as well as improving the management and safety of road construction and work zones. Technology applications range from those aimed at tracking and routing support for maintenance and construction vehicles, to systems designed for monitoring and predicting weather conditions, to applications aimed at construction and work zone management. Some examples include:
ITS technologies can be used to keep track of maintenance and construction vehicles such as snow ploughs – so that operators can monitor whether required tasks are being carried out as planned. ITS can also be used to monitor the condition of maintenance and construction vehicles – using on-board sensors to alert users of any required maintenance or repair activities. (See On-board Monitoring and Telematics)
Using Road Weather Information Stations (RWIS) and other similar environmental sensors (whether fixed location or on-board maintenance vehicles), ITS can help collect accurate, localised information about the weather – including road surface conditions. ITS can also help in the processing of the data and in disseminating information to the public. Information from RWIS can help detect hazardous conditions – such as icy roads, high winds, dense fog – and to plan, more effectively, winter maintenance operations and optimise resource allocations. (See Weather Monitoring)
Winter maintenance operations can be supported by systems that monitor and track routes for snow ploughs and grit spreaders – to determine the correct roadway treatment needed. This will be based on current and predicted weather information and information collected from environmental sensors. (See Weatther Management)
ITS can play a key role in helping improve the safety of work zones and construction sites on highways – as well as better manage the flow of traffic through the work zone. Information collected from permanent and temporary ITS monitoring facilities can be used to better control traffic and to provide advisory and warning messages to drivers – for example through dynamic message signs (DMS). The traffic information collected from the work zone can also be shared with traffic operations centres and to support traveller information systems. (See Work Zones)
ITS technologies can be used to monitor the condition of critical infrastructure such as bridges and road tunnels. Information from fixed sensors as well as vehicle-based sensors play a part. One recent idea is to use information from probe vehicles – about their vertical acceleration – to determine the pavement surface condition and detect different types of distress, such as potholes or surface roughness. (See Probe Vehicle Measurements)