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ITS: Driver Distraction Issues

Most counties already have rules that govern the use of technology inside vehicles to reduce driver distraction. Most commonly these concentrate on the use of mobile phones or screen based infotainment. However, potentially, C-ITS introduces a new paradigm of risk


This of course is a contradiction to the very ethos of C-ITS to improve safety. But the message is clear that we have to be careful not to introduce new risks when introducing C-ITS services, and Administations have to ensure that their regulations adequately extend their safety provisions to embrace the introduction of C-ITS. The issues of driver distraction and information display therefore affect the design of all aspects of C-ITS service provision, and are a critical factor in C-ITS system design and instantiation. 


We can see that driver distraction has become an increasing concern amongst road safety experts, with the increasing range of technologies within vehicles creating the potential for drivers to have their attention taken away from the driving task. C-ITS has the potential to create further distractions if not implemented appropriately.



Distraction  is when drivers divert their attention away from the driving task to focus on another activity instead. Distraction can come in several ways :

  • Visual – eyes off the road (or focusing on the wrong part)

  • Manual – hands off the wheel

  • Cognitive – mind off the road

  • Biomechanical -  requiring action on the part of the driver


While C-ITS have the potential to increase safety, and, for example, collision warning systems will be designed to only notify a driver by exception (i.e. an alarm would be generated only when a crash was likely and the driver needed to take evasive action), these alarms should therefore not affect the general driving task the majority of the time. However, designers will need to be careful to ensure that such warning alarms are sufficiently intuitive that drivers immediately know what to do; poorly designed alarms could decrease safety if they divert attention from the immediate risk or create confusion.


‘Infotainment’ applications may create more of an on-going distraction risk; this is however already an existing risk with infotainment systems today. C-ITS channels may create new ways for this content to be shared with a vehicle, but it is not expected that this will substantially change the risks involved associated with ‘infotainment’.



The readers attention is again drawn particularly to the standards deliverables of ISO TC22 especially, International Standards Organization (ISO) TC 22 SC 13 WG 8 – Vehicle Ergonomics, Distraction metrics (measurement of distracting tasks) and design guidelines (e.g., prioritization)


and  the Society of Automotive Engineers (SAE) Safety & Human Factors Committee.


NOTE: The following list is illustrative and does not claim to be a complete list.




  • ESOP - Commission of the European Communities (2007) Commission Recommendation on Safe and Efficient In-Vehicle Information and Communication Systems; Update of the European Statement of Principles on Human Machine Interface

  • JAMA - Japan Automobile Manufacturers Association Guidelines for In-Vehicle Display Systems, Version 3.0, 2004

  • Alliance of Automobile Manufacturers (AAM) Statement of Principles, Criteria and Verification Procedures on Driver Interactions with Advanced In-Vehicle Information and Communication Systems, June 26, 2006

  • International Telecommunications Union ITU-T FG Distraction Recommendations

    • P.UIA—ITU-T Recommendation on automotive user interface requirements.

    • G.SAM—ITU-T Mechanisms for managing the situational awareness of drivers.

    • G.V2A—ITU-T Recommendation on an automotive interface for applications external to the vehicle gateway.


  • Car Connectivity Consortium –

    • Driver Workload Guidelines for MirrorLink™ Mobile Applications

    • “drive-ready” certification to MirrorLink™ apps. that are deemed not to adversely affect driving.

    • Guidelines for developers are based on existing distraction guidelines (i.e., ESOP, JAMA and Alliance).



In Europe, the "ESOP" provides principles primarily to in-vehicle information and communication systems intended for use by the driver while the vehicle is in motion. ESOP applies to systems and functionalities in OEM-, aftermarket-, and nomadic (portable) systems.


ESOP                     European statement of principles


ESOP covers the following aspects:

  • Installation

  • Information presentation

  • Interface with displays and controls

  • System behaviour



ESOP Design objectives

  • The system supports the driver and does not give rise to potentially hazardous behaviour by the driver or other road users.

  • The allocation of driver attention while interacting with system displays and controls remains compatible with the attentional demand of the driving situation.

  • The system does not distract or visually entertain the driver.

  • The system does not present information to the driver which results in potentially hazardous behaviour by the driver or other road users.

  • Interfaces and interface with systems intended to be used in combination by the driver while the vehicle is in motion are consistent and compatible.


US NHTSA Distraction Guidelines

The objective of USA NHTSA distraction guidelines is to "Minimize driver distraction from electronic devices by encouraging better driver-device interfaces"

 Conformance is voluntary;

 Guidelines envisage implementation in three phases:

  • Phase 1 –Visual-manual interfaces for devices installed by vehicle manufacturers (2013)

  • Phase 2 –Portable and aftermarket Devices (future work)

  • Phase 3 –Voice-based auditory interfaces (future work)



The overall context of C-ITS driver distraction and overload issues


We have to ensure that potential driver distraction and display issues created by C-ITS service provision are not viewed in isolation.


C-ITS service provision is simply yet another potential source of driver distraction of visual or audible overload.

Indeed, designed wisely, C-ITS service provision may often be used to, and indeed should reduce such overloads.



Regulators need to ensure that elevant terms such as ‘visual display unit’ and ‘driver’s aid’ are properly  defined in the ‘Highway Code/Driving Rules’ of most countries. (too often they are not).


Each Jurisdiction need to clearly define what aids it allows, and which aids it does not allow and have clear rules available. In many, but not all, countries, devices providing C-ITS applications would likely fall under the definition of a ‘driver’s aid’ or similar and be allowable under the road rules.


But In addition to ensuring that C-ITS meets safety objectives, legislation may be required to ensure that legitimate C-ITS functions are legalised and that drivers’ using the technology are not caught by laws prohibiting the use of mobile phones while driving. Any required changes to the law will need to be addressed by jurisdictions on a National or State basis.


For example if a safety service, say an ice and obstacle alert, normally provided using 5.9 GHz technology, is automatically switched to 4G because of an overload on the 5.9 GHz band, the administration needs to ensure that it does not fall foul of any regulation banning the use of a mobile phone while driving. At the moment, most, but not all, administrations allow "hands-free" phone use, but as growing evidence is collated that even hands free, a telephone conversation is an unnaceptable distraction to driving, if the juisdiction tightens the rules rearding mobile phone use, it does not accidentally, in so doing, prohibit a means of providing a useful C-ITS safety service.




C-ITS will provide more information to drivers to empower them to make better driving decisions, at least in its early development when C-ITS is expected to be, at least initially, largely based on advisory systems that require human recognition of the signals. The challenge for designers is to achieve this without overloading the driver’s cognitive load. Messages must be prioritised in order to ensure that the driver receives critical information at the critical time. Drivers should be able to distinguish a critical message from a host of other in-vehicle systems competing for his or her attention.


Safety is a primary objective of C-ITS, but there is a risk that its introduction will inadvertently compromise safety in certain scenarios. The challenge for manufacturers and C-ITS service providers is to provide more in-vehicle information, or enable more selective prioritised presentation of information, through new systems without unnecessarily distracting, overwhelming or confusing drivers.


The American Automobile Association Foundation for Traffic Safety defines driver distraction as occurring:

when a driver is delayed in the recognition of information needed to safely accomplish the driving task because some event, activity, object or person within or outside the vehicle compelled or tended to induce the driver’s shifting attention away from the driving task.” 


It has alternatively been defined as ‘the diversion of attention away from activities critical for safe driving toward a competing activity.’


Driver distraction can be caused by the actions of the driver, for example adjusting the radio, answering a phone or texting; or it may be caused by unexpected visual, auditory or haptic experiences that are outside the driver’s control, such as a distracting billboard image, or sudden in-vehicle high pitched tone or vibration.


It may also be caused by an active screen demanding attention, a visual or audible warning, or by an inappropriate warning. For example, if a forward collision warning system indicated a medium risk of collision that demanded the driver’s attention looking ahead, but there was an unannounced higher critical level situation of a side impact collision which was unnoticed because of the driver’s attention being focussed on the less imminent threat.



But it should be borne in mind that C-ITS safety applications can also help protect against the results of distraction, by providing warnings of imminent collisions (such as rear-end collisions) that may be caused by distraction. Future technology could assist with managing distraction, for example by varying the options and functions presented to a driver based on the driver’s experience, vehicle speed, weather and current traffic conditions, in order to ‘lock down’ the technology in riskier situations.


At issue is the loss of concentration that these acts may cause, and while driver distraction data is difficult to measure and not as consistently collected as speed or alcohol data, driver distraction is acknowledged as a common source of crashes. Given the newness of C-ITS there is even less empirical research about its impact on drivers than other forms of distraction.


The scenario of most concern is nonetheless clear: where an in-vehicle C-ITS warning startles the driver and contributes to a collision.


C-ITS does not function in isolation but requires human recognition of the signals and timely and proportionate responsiveness. This reliance on human factors could create risks. C-ITS applications providing traveller information to drivers could also prove a source of distraction.

As in-vehicle technologies increase, C-ITS will emerge in the marketplace to compete with a host of other information-providing systems and technologies. In-vehicle technology may include systems built into the vehicle, personal navigation devices or smartphones (or a combination of these devices). This could result in drivers ignoring the warnings produced by C-ITS or becoming distracted by the warnings. Alternatively, the package of C-ITS technologies may result in a range of warnings and signals competing for the driver’s attention and could result in overwhelming the driver. Warnings need to be carefully timed and prioritised.


In addition to ensuring that C-ITS is designed to meet safety objectives, legislation will need to confirm that C-ITS devices are legal and not caught in the net of laws prohibiting the use of mobile phones while driving (see above) . It also remains an ongoing challenge to keep the laws, standards and guidelines up-to-date with changing technology: ‘it is important that standards addressing driver distraction be valid and applicable independent of type of device, manufacturer and level of experience of driver/ user'. 


Potential risks include:

  • An increasing cognitive load on drivers: C-ITS will provide more information to drivers which should empower them to make better driving decisions. The risk is that they will be overloaded with information and decision-making will worsen in critical situations as a result.

  • Prioritising signals: with a greater volume of information and a range of signals competing for the driver’s attention, messages must be prioritised in order to ensure that the driver receives the critical information at the critical time – and be able to distinguish that message from the host of others.

(ISO TC 22 SC13 WG8 and the SAE Safety and Human Factors Committee have produced standards for message prioritization, notably:  SAE J2395 ITS In-Vehicle Message Priority Task Force and ISO/TS 16951:2004  Road vehicles — Ergonomic aspects of transport information and control systems (TICS) — Procedures for determining priority of on-board messages presented to drivers)


  • Prioritising systems: a critical C-ITS warning to a driver, perhaps involving both an audio and a visual message, could be undermined if competing with other in-vehicle systems (3.8). For example, the audio message may not be clear when the navigation system is providing turn-by-turn directions and the mobile phone is notifying the driver of new text messages and music is playing. Compatibility between systems that enable prioritisation is possible when C-ITS is built into the vehicle, but prioritising systems is a much greater risk when C-ITS is based on after-market devices. The risk may also be higher in commercial vehicles that have additional in-vehicle systems. Significant work in this area has been undertaken in the aviation industry, however that is a much more closely controlled environment.


  • It is important to recognize that warnings are designed to get a person’s attention, communicate the nature of the hazard, it’s severity, urgency and an appropriate response.  Warnings are distracting by nature.  Collision warning need to be attention getting.  However, prompts for location based services may have some urgency but they are not safety critical.


Distraction reduces situation awareness and impairs driving performance. Risk increases with exposure to a hazard. With distraction, risk can vary with: 

•             type of distraction  - visual, manual and cognitive

•             timing 

•             duration

•             frequency

•             intensity

It is therefore important that good design rules and guidance can help detail the location and format of dashboard information display, including the placement of speedometers and odometers. But generally, existing design rules do not prescribe the location and format of additional information, such as changes to the speed limit, real time traffic and roadwork advice or the location of approaching vehicles, nor prioritisation between visual and audible warning. As early ITS applications have been introduced, screen displays and warnings current vary widely between auto-manufacturers.


As and when C-ITS generated information becomes available to drivers, the current information display regulations may require updating, more so if C-ITS information display becomes mandatory.  Also the work of ISO 22 TC 13 WG 8 has put much effort in advice for integration of warnings (especially ISO TR 12204) and should be taken into account.


Current work at NHTSA is designed to provide a set of human factors design principles for driver-vehicle interfaces (DVIs), as well as basic human factors concepts in respect of safety messages in visual, auditory or haptic formats for light and heavy vehicles, and so NHTSA may provide additional resource for those considering these issues.


See ISO TR 17427-10 (of which CSI was the editor and prome author so you will see many similarities and consistencies with this summary, but greater detail and referencing)

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