SAE INTERNATIONAL J2735™ MAR2016 Page 18 of 267
3.1.40 Functional-area Data Dictionary (FADD): A data dictionary that is intended to standardize data element syntax,
and semantics, within and among application areas within the same functional area. This DSRC Standard is a FADD.
3.1.41 Host Vehicle (HV): The equipped vehicle about which a given use case may be constructed. The Host Vehicle
(HV) can be a transmitting vehicle, or a receiving vehicle, or both – this distinction is made clear in the use case
description. There is typically only one Host Vehicle in any use case.
3.1.42 Infrastructure: Any roadside device which supports V2V/V2I communications flows (message exchanges),
including but not limited to DSRC RSU devices. At this time, the primary V2V uses cases and data flows require only
moderate interaction with the Infrastructure for activities such as security.
3.1.43 Ingress: In the context of this Standard, an ingress is a flow of vehicular or other types of traffic approaching an
intersection on one or more of the defined lanes of travel.
3.1.44 Intelligent Transportation Systems (ITS): Systems that apply information technology to transportation
challenges. Another meaning of the ITS acronym is integrated transportation systems, which stress that ITS systems will
often integrate components and users from many domains, both public and private. ITS improves transportation safety
and mobility and enhances productivity through the integration of advanced communications technologies into the
transportation infrastructure and in vehicles. Intelligent transportation systems (ITS) encompass a broad range of wireless
and wire line communications-based information and electronics technologies. - See more at:
http://www.its.dot.gov/faqs.htm#what
3.1.45 Interoperability: The ability to share information among heterogeneous applications and systems.
3.1.46 Intersection: In the context of this Standard, an intersection is a nexus where two or more approaches meet and
vehicles and other types of users may travel between the connecting links. If signalized, the modes of allowed travel are
reflected in the signal phases, the geometry of the intersection, and local regulatory environment. This standard conveys
some of this information in messages: specifically the MAP message conveys the road geometry, while the SPAT
message conveys the current signal indication to control movement in the intersection."
3.1.47 Intersection Control Beacon: A beacon used only at an intersection to control two or more directions of travel.
3.1.48 Interval: In the context of signal timing, the part of a signal cycle during which signal indications are stable and do
not change. In the SPAT message the current timing value for the remaining interval time estimate as well as the
anticipated interval for yellow change interval is provided for each lane. Because signal interval times commonly change
based on triggering events in many types of signaling systems, the value provided in the SPAT message may represent a
minimal value that is extended and updated as the message is re-issued each time.
3.1.49 Interval Sequence: The order of appearance of signal indications during successive intervals of a signal cycle.
3.1.50 International Traveler Information Systems (ITIS): The term commonly associated with the SAE J2540-2
standard for incident phrases developed by the SAE ATIS Committee in conjunction with ITE TMDD and other standards.
This work contains a wide variety of standard phrases to describe incidents (i.e., a traffic accident) and is used throughout
the ITS industry. The codes found there can be used for sorting and classifying types of incident events, as well as
creating uniform human-readable phrases. ITIS phrases can also be freely mixed with text and used to describe incidents,
accidents, weather reports, roadway signage, and other content types.
3.1.51 Lane: In the context of this Standard, a lane is a portion of the transportation network (typically a section of
roadway geometry) which is being described in terms of its centerline path and various attributes. In the DSRC message
set, the lane object is used to represent lanes. Lanes consist not only of sections of “drivable” roadway traversed by motor
vehicles, but other types of lanes including pedestrian and bicycle walkways, train tracks, transit lanes, and certain types
of dividers and barriers. When used in describing an intersection, a lane is often defined for each possible path into and
out of the intersection (e.g. within the MAP message). In use, the current signal phase (and therefore the allowed
movements) that is applicable to that lane or its approach at a given point in time is provided in the SPAT message.
3.1.52 Lane-Use Control Signal: A signal face displaying signal indications to permit or prohibit the use of specific lanes
of a roadway or to indicate the impending prohibition of such use.