ISO/TR 17739-1:2026

Technical
Report
ISO/TR 17739-1
First edition
Intelligent transport systems —
2026-01
Roadside infrastructure supported
location-based services on nomadic
and mobile devices for urban
connected automated mobility —
Part 1:
General information and use case
definition
Systèmes de transport intelligents — Services basés sur la
localisation supportés par l'infrastructure routière pour
les appareils nomades pour une mobilité automatisée et
connectée —
Partie 1: Informations générales et définition des cas d'utilisation
Reference number
© ISO 2026
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ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 General Information . 3
4.1 Nomadic device supported road safety service .3
4.2 Access technology in nomadic device .4
4.3 Actors .4
4.4 Communication architecture .6
5 Use Cases . 7
5.1 Use Case 1.8
5.2 Use Case 2.9
5.3 Use Case 3.11
5.4 Use Case 4. 13
5.5 Use Case 5. 15
5.6 Use Case 6.17
5.7 Use Case 7.19
5.8 Use Case 8.21
5.9 Use Case 9.24
5.10 Use Case 10.27
5.11 Use Case 11 . 29
5.12 Use Case 12 .31
5.13 Use Case 13 . 33
5.14 Use Case 14 . 34
5.15 Use Case 15 . 36
5.16 Use Case 16 .37
Annex A (informative) Cybersecurity for roadside infrastructure supported location-based
services for connected automated mobility .40
Bibliography .42

iii
Foreword
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Any feedback or questions on this document should be directed to the user’s national standards body. A
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iv
Introduction
Conventional road safety services in intelligence transport systems (ITS) area have been mostly provided
as vehicle-centred road safety services by exchanging road safety ITS messages among ITS stations (i.e.
roadside ITS station, central ITS station, vehicle ITS station). However, even though lots of ITS based road
safety services have been deployed in an urban localized area such as signalized intersection, roundabout,
T-intersection, etc., the fatality rate related with a vulnerable road user (VRU) such as pedestrians, bicyclists
as well as road vehicles without equipped ITS stations still remains high.
In order to improve road safety of VRUs, a nomadic device (i.e. a personal ITS station) can be used as a not
only short range vehicle to everything (V2X) communication-supported device but also a long range V2X
communication-supported device to exchange status and intent messages with conventional ITS stations
including personal ITS station, vehicle ITS station, roadside ITS station, and central ITS station. In addition,
a sensor-equipped roadside ITS station with an AI-supported road user behaviour detection function
can support overall road safety enhancement services. It does so by sharing road users' status or intents
information with nomadic device road users such as VRUs and road vehicles without equipped ITS stations.
This document specifies general information and use-cases to provide road safety enhancement services in
a localized urban area by sharing status or intent messages between all types of road users with nomadic
device and conventional ITS stations including a sensor-equipped roadside ITS station.

v
Technical Report ISO/TR 17739-1:2026(en)
Intelligent transport systems — Roadside infrastructure
supported location-based services on nomadic and mobile
devices for urban connected automated mobility —
Part 1:
General information and use case definition
1 Scope
This document defines general information and use cases for providing road safety enhancement services to
all types of road users with a nomadic device in urban localized areas by sharing status or intent messages
between nomadic device users and conventional ITS stations. The road users in this document include
all type of road users with nomadic device such as vulnerable road users (VRU) including pedestrians,
bicyclists, kickboard users, as well as connected automated mobility users including conventional vehicles,
automated or connected driving system equipped vehicles. In addition, this document considers a sensor-
equipped roadside ITS station with AI-supported road user behaviour detection function to support overall
road safety enhancement services by sharing status or intents information of all type of road users such
as VRUs without a nomadic device and road vehicles without equipped ITS stations. This document also
specifies general information, such as category of nomadic device supported road safety service, overall
access technology in nomadic device, actors, and communication architecture to support use cases.
This document also defines safety enhancement use cases to enhance overall road safety of all types of
road users with nomadic device as well as road users without nomadic device with a connectivity of sensor-
equipped roadside ITS station. The use cases are applicable to provide road safety enhancement service in
a specific urban localized area such as an un-signalized intersection, T-intersection, roundabout, low speed
zone, school zone, no turn on red zone, weaving area, etc.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
access technology
technology employed in a communication interface to access a specific medium
[SOURCE: ISO 21217:2020, 3.1]
3.2
central system
intelligent transport system (ITS) in the backend, e.g. traffic control centre, traffic management centre, edge
or cloud system operated by road authorities, ITS application suppliers or automotive OEMs equipped with
a central ITS station
3.3
connected vehicle
vehicle that contains a connected device
3.4
hybrid communications
composition of multiple access technologies and communication protocols combined to provide
complementary or redundant communication channels
[SOURCE: ISO 21217:2020, 3.7]
3.5
intent
planned future behaviour of a road user, including but not limited to trajectory, speed, turning direction,
and lane change
3.6
intelligent transport system (ITS) station
ITS station
ITS-S
functional entity comprised of an ITS-S facilities layer, ITS-S networking and transport layer, ITS-S access
layer, ITS-S management entity, ITS-S security entity and ITS-S applications entity providing ITS services
Note 1 to entry: From an abstract point of view, the term "ITS station" refers to a set of functionalities. The term is
often used to refer to an instantiation of these functionalities in a physical unit. Often, the appropriate interpretation
is obvious from the context. The proper name of the physical instantiation of an ITS-S is ITS station unit (ITS-SU).
[SOURCE: ISO 21217:2020, 3.15]
3.7
localized communications
communications with nearby stations without involving support of an infrastructure network
[SOURCE: ISO 21217:2020, 3.53]
3.8
networked communication
communication using support of an infrastructure network
[SOURCE: ISO 21217:2020, 3.60, modified — "communications" revised to "communication". ]
3.9
sensor-equipped roadside intelligent transport system (ITS) station
roadside ITS station with equipped sensors such as camera, LiDAR, or radar which make vehicle to
everything (V2X) more comprehensive with object perception, detection and tracking functionalities
3.10
vehicular WiFi
short-range localized communications (3.8) WiFi access technology (3.1) specifically designed for vehicular
localized communications
Note 1 to entry: An example of vehicular WiFi is IEEE 802.11 operating outside the context of a basic service (OCB),
also known as IEEE 802.11p[51], used in the 5,9 GHz frequency range reserved for ITS services with profile standards
named ITS-G5 (ETSI) in Europe and Australia, and US-DSRC in North America and their harmonization at ISO (
ITS-M5).
3.11
vulnerable road user
VRU
non-motorized road user, such as a pedestrian and cyclist as well as a motor-cyclist and person with
disabilities or reduced mobility and orientation
3.12
vehicle to network to everything
V2N2X
anything connected to a vehicle via a "network" connected to networked communication
3.13
vehicle to network to everything ecosystem
V2N2X ecosystem
comprehensive interaction system in which data is exchanged between various types of ITS stations
connected by networked communication
Note 1 to entry: Data can be exchanged based on interaction between information sharing instances connected to a
central ITS station.
3.14
vehicle to network to everything intelligent transport system message
V2N2X ITS message
message exchanged between ITS stations (e.g., vehicle ITS station, personal ITS station, RSU ITS station and
central ITS station) connected to the networked communication to provide any ITS service
3.15
vehicle to network to everything container
V2N2X container
part of a message exchanged via networked communication that contains metadata necessary to provide
interoperable services
4 General Information
4.1 Nomadic device supported road safety service
Nomadic device supported road safety services can be categorized as road safety enhancing services and
[1]
road safety critical services as below:
— nomadic device supported road safety enhancing services can enhance the safety of the road user
including not only the VRU but also the driver with nomadic device from potential road accident or
work zone. To provide road safety enhancing services, the road users with nomadic device such as VRU,
driver inside a connected or non-connected vehicle can share timely and relevant road safety enhancing
information in the form of a standardized V2X message to each other in the order of seconds;
— nomadic device supported road safety critical services can improve the safety of the road user including
not only the VRU but also the driver with nomadic device from immediately following the vehicle to
vehicle or vehicle to VRU collision. To provide road safety critical services, the road users with nomadic
device such as VRU, driver inside a connected or non-connected vehicle can share timely and relevant road
safety critical information in the form of standardized V2X message to each other in micro-seconds;
sensor-equipped roadside ITS stations can provide both road safety enhancing information and critical
information of road users without nomadic device to road users with nomadic device.

4.2 Access technology in nomadic device
The access technologies that nomadic devices support to enhance road safety and safety-critical services
[2]
can be divided into two categories; localized communications and networked communications. The access
technologies on the nomadic device include all instances of access technologies as below;
— access technologies to support localized communication includes 5,9 GHz vehicular WiFi such as IEEE
802.11p group, 5,9 GHz cellular V2X such as LTE-V2X, 5G-V2X and other short-range communication
technologies to support ad-hoc communications;
— access technologies to support networked communications includes 3G, 4G, 5G or 6G.
The access technology used by the nomadic device can be selected by the service provider of the nomadic
device, considering the performance of the access technology, such as latency, data transmission rate and
success (or error) rate, depending on the type of the road safety service provided.
4.3 Actors
This clause specifies actors for providing nomadic device-supported road safety enhancing and critical
services. The actors are mainly divided into two categories:
— actors with nomadic device supported by localized communication that broadcast and receive road
safety enhancement and critical ITS messages to and from all types of the ITS stations based on direct
communication;
— actors with nomadic device supported by a networked communication that broadcasts and receives
road safety enhancement and critical ITS messages from all types of the ITS stations based on infrastructure
network communication.
Nomadic device supporting networked communication within the V2N2X ecosystem can interact with
other networked domains by exchanging the V2N2X ITS message including the V2N2X container, for service
requests and related data transfer.
The following actors are included in the use cases contained in this document:
— connected road users with nomadic device:
— connected road users with nomadic device including VRUs, drivers or passengers in vehicle such as
connected (or automated) vehicle, non-connected vehicle in localized communication environment;
— connected road users with nomadic device including VRUs, drivers or passengers in vehicle such as
connected (or automated) vehicle, non-connected vehicle in localized communication environment;
— connected road users with nomadic device including VRUs, drivers or passengers in vehicle such as
connected (or automated) vehicle, non-connected vehicle in hybrid communication environment.
In addition to the actors, this document also specifies interactions with the following actors for nomadic
device-supported road safety enhancing critical service:
— vehicle ITS station:
— vehicle ITS station can equip with vehicle manufacturer’s road safety enhancing and critical service
application;
— vehicle ITS station can interact with nomadic device users i.e. VRUs, drivers and passengers in the
vehicle in hybrid communication environment;

— vehicle ITS station can interact with a sensor-equipped roadside ITS station in hybrid communication
environment.
— sensor-equipped roadside ITS station:
— sensor-equipped roadside ITS stations can interact with nomadic device users. i.e. VRUs, drivers or
passengers in the vehicle in hybrid communication environment;
— sensor-equipped roadside ITS station can interact with vehicle ITS station in hybrid communication
environment.
— central ITS station:
— central ITS station can interact with nomadic device users i.e. VRUs, drivers or passengers in the
vehicle, and sensor-equipped roadside ITS station in networked communication environment;
— central ITS station can interact with other central system in different networked communication
domain in networked communication environment;
— central ITS station can include following application server;
— infrastructure owner and operator application server (IOO AS): managed by public
infrastructure owner and operators, the IOO domain represents regional entities, such as cities,
road authorities, or parking providers, that offer automotive and transport services based on
their own infrastructure and sensor networks;
— service provider application server (SP AS): managed by specific service providers (e.g., SP "A",
SP "B"), the SP AS delivers domain-specific services for ITS applications, such as VRU protection,
MAP services, traffic information, and fleet operations;
— vehicle OEM application server: managed by specific vehicle OEMs, this station controls
communication between vehicles and backend services, operating as a secure proxy and filter
for data flow while enabling vehicle-specific services.
— information sharing system:
— facilitating scalable and interoperable data exchange among central ITS stations within same or
different service domains by managing information sharing instances to process and distribute ITS
messages across localized and networked communication domains.

4.4 Communication architecture
Key
localized communication
networked communication
nomadic device
Figure 1 — Communication architecture of nomadic device supported access technology
As shown in Figure 1, a nomadic device (or personal ITS station) can be connected through multiple access
technologies including:
— localized communication;
— networked communication;
— hybrid communication (i.e., both localized communication and networked communication).
The localized communication used for the direct exchange of data between vehicles and their surrounding
[2]
environments (i.e. nomadic devices (personal ITS stations), vehicle ITS stations, roadside ITS stations).
The following ITS message flows are supported by localized communication for road safety enhancing or
critical use cases such as vehicle-to-device warning, or VRU interactions:
— ITS messages can be exchanged between a nomadic device (personal ITS station) and a vehicle ITS
station;
— ITS messages can be exchanged between a nomadic device (personal ITS station) and a roadside ITS
station (or sensor-equipped roadside ITS station);
— ITS messages can be exchanged between a vehicle ITS station and a roadside ITS station (or sensor-
equipped roadside ITS station).
Compared with localized communication, the networked communications used for long-range or end-to-end
communication among nomadic devices (personal ITS stations), vehicle ITS stations, roadside ITS stations,

and central ITS stations at the backend. The following ITS message flows are supported by networked
communication:
— ITS messages can be exchanged between a nomadic device (personal ITS stations) and a central ITS
station;
— ITS messages can be exchanged between a vehicle ITS station and a central ITS station;
— ITS messages can be exchanged between central ITS stations within the same or different service;
— ITS messages can be exchanged between a nomadic device (personal ITS stations) and a central ITS
station within the same or different service domains;
— ITS messages can be exchanged between a vehicle ITS station and a central ITS station within same or
different service domains.
The combination of the above ITS message flows enable interworking among all ITS stations, facilitating
hybrid communication across communication modes.
Key
localized communication
networked communication
information exchange between countries / regions
nomadic device
Figure 2 — Communication architecture for ITS message exchange among ITS stations using
information sharing domain
As shown in Figure 2, an information sharing domain (ISD) enables the establishment of an information
sharing network between central ITS stations within one or multiple regions (countries), where central ITS
stations of localized or networked communication are connected with groups of ITS stations including a
nomadic device (personal ITS station) and a vehicle ITS station. This facilitates data exchange across central
ITS stations within one or multiple regions supporting scalable nomadic device-supported road safety
enhancing or critical service as well as efficient backend communication across regions.
5 Use Cases
This clause describes the use cases.

5.1 Use Case 1
This sub-clause describes the Use Case 1.
Use case name Connected object collision avoidance warning alerts
Category Road safety critical service
Short descrip- This use case describes the automatic detection of collision risk through continuous loca-
tion tion and situation information transmission and reception.
Goal VRU protection and collision avoidance
Constraints Use of localized communications or networked communications that will meet the perfor-
mance requirements for this use case for nomadic and mobile devices
Geographic All road area where connected devices can be located
scope
Actors Connected road users with nomadic device
Central ITS station
Illustration
(example)
Key
nomadic device (personal ITS station)
Preconditions 1) The central ITS station and sensor-equipped roadside ITS station supports the
service by receiving messages containing existence and location information of
un-connected VRUs from a sensor-equipped roadside ITS station and forwarding
messages to nomadic device users approaching to the location where VRUs are
detected.
2) The nomadic device implements an algorithm that can automatically assess the
collision risk between nomadic device users.
3) The nomadic device continuously transmits and receives the location and
situation information of the user.
4) The nomadic device can generate warning alerts and provide other nomadic
device users with warning alerts.
Main flow (ex- Nomadic devices to the central ITS station
ample)
1) The use case begins when a connected road user enters the service range
that the central ITS station can support (the same assumptions apply if other
mediums are used).
2) The nomadic device sets the (connected) road user type, either vehicle or VRU.
3) The nomadic device requests a service by sending a message (BSM, CAM, PSM,
VAM) including user and location information to the central ITS station.
The central ITS station to nomadic devices
1) The central ITS station forwards the received user and location information
messages (BSM, CAM, PSM, VAM) to the nomadic device user around that
location information.
Using the messages, the nomadic device analyses the risk of collision between
nomadic device users in real time and warns them via screen or sound.
2) The case ends.
Alternate N/A
flow(s)
Post-conditions Potential collision is avoided.
Information BSM/CAM
requirements
Vehicle ID (for tracking), vehicle location, vehicle heading, vehicle speed, vehicle type
PSM/VAM
VRU ID (for tracking), VRU location, VRU heading, VRU speed, VRU type
Issues N/A
Source docs/ SAE J2735™, SAE J2945/9, ETSI ITS EN 302 637-2, ETSI ITS TS 103 300-3
references
5.2 Use Case 2
This sub-clause describes the Use Case 2.
Use case name Un-connected object collision avoidance warning alerts
Category Road safety critical service
Short descrip- This use case provides warning alerts by detecting a risk of collision for un-connected road
tion users (vehicles and VRUs)
Goal Un-connected VRU protection and collision avoidance
Constraints Use of localized communications or networked communications that will meet the perfor-
mance requirements for this use case
Geographic Localized to a specific area within any sensor-equipped roadside ITS station detection
scope coverage
Actors Connected road users with nomadic device
Un-connected road user under sensor-equipped roadside ITS station coverage
Central ITS station
Illustration
(example)
Key
nomadic device (personal ITS station)
sensor-equipped roadside ITS station
Preconditions 1) The central ITS station / sensor-equipped roadside ITS station supports the
service by receiving messages containing existence and location information of
un-connected VRUs from sensor-equipped roadside ITS station and forwarding
messages to nomadic device users approaching to the location where VRUs are
detected.
2) The nomadic device implements an algorithm that can automatically assess the
collision risk between mobile device users.
3) The nomadic device continuously transmits and receives the location and
situation information of the user.
4) The nomadic device can generate warning alerts and provide other nomadic
device users with warning alerts.
Main flow (ex- Sensor-equipped roadside ITS station to the central ITS station
ample)
1) The use case begins when an un-connected road user enters the service range
that the central ITS station can support (the same assumptions apply if other
mediums are used).
2) The sensor-equipped roadside ITS station detects and sends un-connected
road user information obtained through various sensors/communication
technologies including CCTV to the central ITS station.
3) The sensor-equipped roadside ITS station or central ITS station generates
a message (BSM, CAM, PSM, VAM) with location information of detected
disconnected objects.
The central ITS station (or sensor-equipped roadside ITS station) to mobile device app.
1) The sensor-equipped roadside ITS station or central ITS station forwards the
received un-equipped user and location information messages (BSM, CAM, PSM,
VAM) to the mobile device app user around that location information.
2) Using the messages, the nomadic device analyses the risk of collision between
nomadic device users in real time and warns them via screen or sound.
3) The case ends.
Alternate N/A
flow(s)
Post-conditions Vehicle driver is alerted of potential collisions and takes appropriate action to avoid or
mitigate a collision.
Information BSM/CAM
requirements
Vehicle ID (for tracking), vehicle location, vehicle heading, vehicle speed, vehicle type
PSM/VAM
VRU ID (for tracking), VRU location, VRU heading, VRU speed, VRU type
Issues N/A
Source docs/ SAE J2735™, SAE J2945/9, ETSI ITS EN 302 637-2, ETSI ITS TS 103 300-3
references
5.3 Use Case 3
This sub-clause describes the Use Case 3.
Use case name Providing a specific information about an obstacle located in the path of dynamic object
Category Road safety enhancing service
Short descrip- This use case describes the providing a specific information about obstacle located in path
tion of a dynamic object that would lead to the path change with a correlation information
Goal Road user who receive the information/message can recognize that the dynamic object who
encounters obstacles in its path will take unexpected actions in order to avoid the obstacle
Constraints Use of localized communications or networked communications that will meet the perfor-
mance requirements for this use case
Geographic Localized to a specific area within any sensor-equipped roadside ITS station detection
scope coverage
Actors Central ITS station
Connected road users with nomadic device
Un-connected road user under sensor-equipped roadside ITS station coverage
Sensor-equipped roadside ITS station
Dynamic object and obstacles
Illustration
(example)
Key
nomadic device (personal ITS station)
sensor-equipped roadside ITS station
Preconditions 1) Central ITS station /sensor-equipped roadside ITS station supports the service
by receiving messages containing existence and location information of un-
connected VRUs from sensor-equipped roadside ITS station and forwarding
messages to nomadic device users approaching to the location where VRUs
detected.
2) The nomadic device implements an algorithm that can automatically assess the
collision risk between nomadic device users.
3) The nomadic device continuously transmits and receives the location and
situation information of the user.
4) The nomadic device can generate warnings alerts and provide other nomadic
device users with warning alerts.
Main flow (ex- Sensor-equipped roadside ITS station to the central ITS station
ample)
1) The use case begins when a sensor-equipped roadside ITS station/ central
ITS station provides the sensor data sharing service with object information
detected by sensor-equipped roadside ITS station.
2) The sensor-equipped roadside ITS station detects the situation when a dynamic
object encounters obstacles located in its path.
3) The sensor-equipped roadside ITS station determines the correlation between
the dynamic object and obstacles and recognizes that the object need to avoid
the collision with the obstacles and find another path or take unexpected action.
4) The sensor-equipped roadside ITS station sends this situational information to
other road users (receivers) using new message or existing sensor data sharing
message containing the specific information about obstacles along with the
correlation information between the dynamic object and the obstacles using
various method (e.g., Cost map, precise position and dimensions, image/video).
5) Other road users receive the information from the sensor-equipped roadside
ITS station to predict the unexpected movement or path change of the dynamic
object due to the obstacles.
6) The case ends
Alternate N/A
flow(s)
Post-conditions VRUs and vehicles can avoid the collision with other VRUs riding a bicycle.
Information CPM/SDSM
requirements
Object ID (for tracking), Object location, Object heading, Object speed, Object type
New message type is needed
e.g. Dynamic object information, specific obstacle information, correlation information
DENM/RSM
Event information (e.g. event ID, event location, event type, event history)
Issues N/A
Source docs/ SAE J2735™, SAE J2945/9, SAE J2945/4, ETSI ITS EN 302 637-2, ETSI ITS EN 302 637-3,
references ETSI ITS TS 103 300-3, ETSI ITS TS 103 324
5.4 Use Case 4
This sub-clause describes the Use Case 4.
Use case name Warning alert and infra cooperation by transmitting information on students getting on/
off the school bus
Category Road safety enhancing service
Short descrip- This use case describes the safety management and operation of getting on/off the school bus
tion
Goal By transmitting messages on the status of students getting on/off the school bus, the school
bus can request approach warnings, deceleration, and stop from nearby vehicles.
The school bus can transmit the message to the central ITS station and adjust the operation
of road facilities as needed
Constraints Use of localized communications or networked communications that will meet the perfor-
mance requirements for this use case
Geographic Area where school bus gets on/off
scope
Actors Central ITS station
Connected road users with nomadic device
Un-connected road user under sensor-equipped vehicle ITS Station coverage
Illustration
(example)
Key
nomadic device (personal ITS station)
sensor-equipped vehicle ITS station
Preconditions 1) The school bus can detect the location information of students getting on and off
the bus through sensors and send messages to OBE or the nomadic device.
2) The central ITS station / sensor-equipped roadside ITS station supports the
service by receiving messages containing existence and location information of
un-connected VRUs from school bus and forwarding messages to other nomadic
device users around the school bus's location.
3) The nomadic device implements an algorithm that can automatically assess the
collision risk between nomadic device users.
4) The nomadic device continuously transmits and receives the location and
situation information of the user.
5) The nomadic device can generate warnings alerts and provide other nomadic
device users with warning alerts.
Main flow (ex- School bus to vehicle, sensor-equipped roadside ITS station, and central ITS station
ample)
1) The use case begins when a school bus approaches or stops at a pick-up and drop-
off area.
2) The school bus uses the sensing function (camera, LiDAR, etc.) mounted on
the bus, including awareness information, intention information, and situation
information, to collect situation information of students getting on/off
3) The school bus generates a message (BSM, CAM) using the acquired information
and transmit it to surrounding vehicles, roadside ITS station, and the central ITS
station.
4) The school bus sends warning message (DENM, RSM, BSM) or message requesting
deceleration/stop along with the above message.
5) The case ends.
Alternate School bus to vehicle, sensor-equipped roadside ITS station, and central ITS station
flow(s)
1) When surrounding vehicles do not respond to the deceleration/stop request, the
school bus can issue a warning notification to the passengers and surroundings.
2) If the above information is collected by the central ITS station, it can be reflected
in real-time in the adjustment of road facility management operations, if
necessary. (e.g. traffic light signal control)
3) The case ends.
Post-conditions Students can get on and off the school bus safely.
Information BSM/CAM
requirements
Number of students, start/end time of getting on/off) information, age group, etc.
DENM/RSM
Event information(e.g. event ID, event location, event type, event history)
Issues N/A
Source docs/ SAE J2735™, SAE J2945/9, SAE J2945/4, ETSI ITS EN 302 637-2, ETSI ITS EN 302 637-3,
references ETSI ITS TS 103 300-3
5.5 Use Case 5
This sub-clause describes the Use Case 5.
Use case name Warning alerts by collection of weather information and road surface condition information
Category Road safety enhancing service
Short descrip- This use case describes real-time collection of weather and surface condition information
tion on the road to provide warnings
Goal Road condition alerts and hazard warnings
Constraints Use of localized communications or networked communications that will meet the perfor-
mance requirements for this use case
Geographic Localized to a specific area within any sensor-equipped roadside ITS station detection
scope coverage
Actors Central ITS station
Sensor-equipped roadside ITS station
Connected road users with nomadic device

Illustration
(example)
Key
nomadic device (personal ITS station)
sensor-equipped roadside ITS station
Preconditions 1) The central ITS station /sensor-equipped roadside ITS station supports the
service by receiving messages containing existence and location information of
un-connected VRUs from sensor-equipped roadside ITS station and forwarding
messages to nomadic device users approaching to the location where VRUs
detected.
2) The nomadic device implements an algorithm that can automatically assess the
collision risk between nomadic device users.
3) The nomadic device continuously transmits and receives the location and
situation information of the user.
4) The nomadic device can generate warnings alerts and provide other nomadic
device app users with warning alerts.
Main flow (ex- Sensor-equipped roadside ITS station/road user to central ITS station
ample)
1) The use case begins when a connected road user enters the service range that
the roadside ITS station/central ITS station can support (the same assumptions
apply if other mediums are used).
2) Connected road user or sensor-equipped roadside ITS station collects weather
information, road surface conditions, and current road speed limit information
in real time by segmented unit area, time, etc.
3) Using the collected information, the connected road user or sensor-equipped
roadside ITS station generates
...