Infrastructure Based Wireless ITS
Infrastructure based ITS is a term generally used to describe ITS services that are provided without two way communication to the road user. Many of these services are transparent to the road user, although he will be the beneficiary. Traffic signal management, control centre - control centre communications and information systems provide typical examples. Such systems may manage traffic flows, even redirect traffic, and in general these systems have been implemented using copper and fibre optic cables and general communications technology generic standards. Some of these standards are referred to in this book, but the reader who is interested in generic IT/Telecommunications Standards is directed towards books on these subjects. This area is too complex and too generic to be covered within a book on ITS standards. However aspects of such standards that are specifically adapted for ITS are covered in several Chapters of this book.
The traveller becomes aware of such systems most usually when there is a visual interface. Examples here include “Variable Message Signs” which provide relevant information to the driver, but are performed by a computer to a remote display screen using fibre optic or copper cables; “ramp management” where traffic lights control entry to highways; or “green wave” sequenced traffic light operation to both control traffic flow and encourage compliance with speed limits. Arrival and departure boards at stations and airports provide other examples. Two trends are worthy of note.
The first is a trend to use wireless communications for infrastructure↔infrastructure communication. General wireless, usually microwave, standards are used for such systems which are often carried over public networks. Traffic managers are increasingly also using dedicated local systems to collect environmental data, and in some cases communicate with remote traffic signals. Such communications are also commonly carried out using GPRS cellular communications.
There is also a dedicated microwave band allocated within Europe specifically for infrastructure↔infrastructure communications at 64-66 GHz, and this is foreseen as particularly appropriate for ITS communications to end infrastructure nodes or between nodes. This band is adjacent to a band at 63 GHz that is dedicated for ITS. Here it is envisioned that 64-66 GHz will be used to get the communication to the roadside, and 63 GHz will be used to communicate to/from and between vehicles.
The second trend is to communicate to mobile equipment using wireless communications. Currently , this is effected using GPRS or 3G cellular communications, but it is envisaged that once infrastructures to enable quasi-continuous communications to/from vehicles are in place, these will also be able to be used for wireless infrastructure-mobile infrastructure communications.
Examples of Infrastructure based ITS include:
Adaptive Traffic Signal Control
A traffic control system that solves these problems by continuously sensing and monitoring traffic conditions and adjusting the timing of traffic lights according to the actual traffic load.
After Theft Vehicle Recovery
The centralised provision of after theft vehicle recovery services, including:
· User initiated distress calls
· Automated theft warning
· Automated vehicle intrusion and stolen vehicle monitoring
· Stolen vehicle tracking
· Remote vehicle immobilization
Commercial Vehicle Pre-clearance
The commercial vehicle pre-clearance service group provides services that enable commercial vehicles, including trucks and buses to have credentials and other documents, safety status and weights checked automatically at normal road speeds. A principal objective of this service is to effect preclearances with minimal disruption to the vehicle journey and the traffic flow.
Examples services include:
· Non-stop pre-clearance
· Vehicle safety records monitoring
Commercial vehicle administrative processes
This service group is complementary to the service group ‘Commercial Vehicle Pre-clearance’ described above.. It enables hauliers and shippers to purchase annual and ad-hoc credentials, using communications and computer technologies.
Example services include:
· Automated credential filing
· Automated commercial vehicle administration
· Automated border crossings
Control Centre Information Sharing
The automated sharing of traffic management, traffic load and incident data between adjacent Traffic Management Centres, to improve planning, load management, incident management, etc.
Corridor Traffic Management - Surface Street (local road) and Freeway/Highway
Traffic management system to co-ordinate usage of surface street and freeway/highway traffic management.
When congested traffic conditions occur on one roadway, travellers typically respond by shifting to another route, selecting a different roadway (freeway versus surface street), adjusting their trip to another time of day, or remaining on their current route encountering significant delays. These disruptions range in scale, frequency, predictability, and duration. Depending on the cause, they have the potential to affect a number of transportation facilities or modes. Corridor Traffic Management is a management control technique to encourage or discourage certain driver decisions.
Proactively managing and coordinating the control of traffic is a viable and effective strategy to improve the safety, efficiency and reliability of traffic on and between freeways and surface streets (minor roads) within urban corridors. Corridor Traffic Management can reduce travel times, improve travel reliability, increase traffic throughput, decrease crashes, and reduce the number of stops and delay at traffic signals.
Achieving these results requires an aggressive traffic operations program, strong partnerships between agencies, commitment of necessary resources and support, deployment of technology and traffic control systems, development of operational strategies and control plans, and proactive management and control of traffic within freeway corridors in metropolitan areas. Using managed lane strategies, alternate routing of traffic, operational strategies, coordinated control plans, proactive management and control of traffic, and coordinated response to changing conditions offers the potential to achieve significantly greater use of the existing roadway capacity. Within an ITS context refers to the use of data collected through cameras, sensors, probe vehicles used to manage a corridor and the transmission of information to VMS signage and ITS equipped vehicles.
An Archived Data user service provides an ITS historical data archive for all relevant ITS data and will incorporate the planning, safety, operations, and research communities into ITS. It will provide the data collection, manipulation, and dissemination functions of these groups, as they relate to data generated by ITS.
A Data Warehouse service integrates the planning, safety, operations, and research communities into ITS and processes data products for a regional ITS community
ITS data warehouse management supports the archiving and retrieval of data generated by other ITS applications and enables ITS applications that use archived information. Decision support systems, predictive information, and performance monitoring are some ITS applications enabled by ITS information management. In addition, ITS data warehouse systems can assist in transportation planning, research, and safety management activities.
Detection and Confirmation of Incident Presence
The use of data gathered from ITS sources, camera monitoring etc. to support confirmation of incident and advisory to relevant parties; instigation of on-on-site motorist assistance response; on-site traveller assistance; and incident co-ordination and clearance.
Electronic payment systems – Infrastructure Only
Electronic payment systems employ various communication and electronic technologies to facilitate commerce between travellers and transportation agencies, typically for the purpose of paying tolls and transit fares. While most involve direct transactions between a vehicle and the infrastructure, or a payment card in the hands of a traveller and the infrastructure (see appropriate sub Chapter below for details), some schemes, including the world’s largest congestion payment scheme (London), utilize only infrastructure means (video cameras) to collect payment
Emergency Management Systems
ITS applications in emergency management include hazardous materials management, the deployment of emergency medical services, and large and small-scale emergency response and evacuation operations. See appropriate sub chapters below for Emergency management systems that communicate directly with emergency vehicles and vehicles involved in the incident).
Centralised management of violation enforcement using ITS data captured from (usually a combination of) sensors, cameras etc. (and in future potentially also fro other ITS equipped vehicles).
· Enforcement: Access Control
· Enforcement: High Occupancy Vehicle Facility Usage
· Enforcement: Parking Regulation Enforcement
· Enforcement: Speed Limit Enforcement
· Enforcement: Signal Enforcement (E.G. Red Light Violation)
· Enforcement: Emissions Monitoring
Freight Transport Fleet Management
At a multi-modal level commercial fleet management includes logistics and freight management systems. (also covers the use of automatic vehicle location (AVL) to achieve automatic freight carrier location/container location and vehicle-to-control centre communications to provide vehicle location and other status information to the fleet operators despatched-. Where services that require interaction with the vehicle is concerned, see the appropriate sub chapter below). In respect of infrastructure based ITS service provision, includes the use of dynamic despatching systems to improve the efficiency of the fleet management process. These services are implemented in conjunction with the traffic management service group services. This service group includes:
a) Pre-trip information
b) Intermodal terminal conditions
Example services include:
· Commercial vehicle fleet tracking
· Commercial vehicle fleet dispatching
· Freight container tracking
Includes transactions to maintain the ITS information about a shipment from the time of the order by the consignor to the reception of goods by the consignee. The key ITS transactions provide registers of service providers and to enable the goods to be tracked throughout intermodal journeys.
This service group covers the exchange of information about transport of goods across modes. This includes knowledge of where the units transporting the goods are located, plus their condition and status, as well as similar information about the vehicle transporting the unit. It is also possible to locate sub-units, provide customers with information about the progress with the movement of the goods.
Example services include:
Vehicle and container arrival information exchange (users are fleet and intermodal carriers and nodes)
Customer freight information access (users are customers and shippers)
Intermodal centre facility management
Intermodal vehicle and container control
Dangerous goods movement data sharing
Dangerous goods movement data registry
Dangerous goods movement fleet coordination
Dangerous goods movement police / safety coordination
See also Commercial/Freight ITS TARV/CIC
Freeway/Arterial/Highway Traffic Management
Arterial management systems manage traffic along arterial roadways, employing technologies such as traffic detectors, traffic signals, and various means of communicating information to travellers. These systems make use of information collected by traffic surveillance devices to smooth the flow of traffic along travel corridors. They also disseminate important information about travel conditions to travellers via technologies such as dynamic variable message signs and highway advisory radio.
ITS functions that provide freeway/arterial/highway management systems include:
Traffic surveillance systems using detectors and video equipment.
Traffic control measures on entrance ramps using sensor data to optimise freeway travel speeds and ramp meter wait times.
Lane management optimise the effective capacity of freeways and promote the use of high-occupancy commute modes.
Special event transportation management systems control the impact of congestion at stadiums or convention centres.
Dynamic VMS management
Hazardous Materials Monitoring and Management
The central control for the movement of hazardous materials on the road network. includes pre-trip driver authentication, route planning and resource allocation; planning and management of difficult movements; notification of slow moving/wide transports to traveller information advisory systems; liaison with departments for maintenance of National Security, etc. Hazardous Materials Monitoring and Management services include:
· Hazardous Vehicle Pre-clearance
· Hazardous Vehicle Routing data:
· Hazardous Vehicle Incident data
oIssuing post-incident instructions to driver
oLocation of vehicle
oNature of incident
oNature of cargo
High Occupancy Vehicle Facility Management
The organisation and management of High Occupancy Vehicle (HOV) provisions. Including remote enforcement measures, Dynamic lane assignment; traveller advisory support, etc.
Highway Maintenance Management
The use of ITS to support highway maintenance management, including the deployment of portable VMS and dynamic update of signage, speed limit management, on-site worker protection; use of data from ITS sources to predict and manage maintenance activities; use of ITS data to predict and avoid incidents, etc.
Incident Management Systems
Incident management systems can reduce the effects of incident-related congestion by decreasing the time to detect incidents, the time for responding vehicles to arrive, and the time required for traffic to return to normal conditions. Incident management systems make use of a variety of surveillance technologies, often shared with freeway and arterial management systems, as well as enhanced communications and other technologies that facilitate coordinated response to incidents.(
Inter-Modal Highway Junction Management
Freight intermodal change connection points (typically road/rail but also road/air). Intermodal connectors are often not formally part of State Highway System. In respect of infrastructure ITS, the management of traffic flows and interchange to/at/from intermodal change points.
Parking Management includes a variety of strategies that encourage more efficient use of existing parking facilities, improve the quality of service provided to parking facility users and improve parking facility design. Parking Management can help address a wide range of transportation problems and help achieve a variety of transportation, land use development, economic, environmental objectives. ITS can be used to assist parking management by the dynamic interchange of data. ITS can assist parking management, operation and deployment by direct interaction with ITS equipped vehicles. (Examples of ITS assisted parking management which involve direct interaction with ITS equipped vehicles are given in the appropriate sections of this chapter, below). However, ITS assistance for parking management does not have to wait until vehicles are ITS equipped, and infrastructure based ITS is already assisting these operations. Examples of Parking Management strategies include:
· VMS parking assistance. Providing automatically updated identification of parking places available, together with road signage to the parking facilities.
· Dynamic Share Parking. The allocation of parking facilities, by day or time of day, to different organizations based on recent identified usage. Can increase effective car park capacity by 20%-40% (Victoria Policy Transport Institute).
· Dynamic Parking Demand Management, such as:
· Making the most convenient parking spaces available to certain higher-value uses e.g.:
Dynamic allocation of spaces reserved for disabled people.
Dynamic time related occupancy (e.g. short term shoppers in day, residents at night)
Time related demand pricing
More flexible pricing methods which allow motorists to pay for only the amount of time they park, (which makes shorter parking periods relatively attractive).
Dynamic Park and Ride Management
Dynamic Internet based parking pricing and availability (pre-trip)
Reversible Lane Management /Counterflow/Tidal Flow
Terms used in different parts of the world to describe a traffic control system where the direction of traffic is changed according to prevailing or expected traffic conditions. Typically used to improve traffic flow during rush hours. Traffic signals are controlled from a traffic control centre operating lights external VMS and, it is expected, in the future, messages to ITS equipped vehicles.
Response To On-Site Incident Information
ITS function to use available data to formulate appropriate response actions to each identified incident and revise those actions when necessary to minimize incident impacts and post event effects. includes the proposal and facilitation of the appropriate scheduling of predicted incidents, in order to minimize incident potential, incident impacts, and/or the resources required for incident management.
Specific Vehicle Types Priority And Preemption
Central management system control to provide traffic signal priority and preemption for specific classes of vehicles (e.g. emergency service vehicles, public transit etc.) This service can be effected by a number of technologies, but the dominant technologies ar; ITS communications equipped vehicles or vehicles equipped with an RFID tag, together with ITS beacons or RFID readers at traffic control signals. The data of an approaching priority vehicle can also be relayed to VMS signs both outside the vehicle and on the screens of ITS equipped vehicles, and to traffic control officers by means of audible or visual messages.