ITS Communications & Information Protocols

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.