Road Network Operations
& Intelligent Transport Systems
A guide for practitioners!

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Design of ITS for Vehicles

With the growth in deployment of ITS and the information and communication options available to drivers, the modern car has been described as ‘a SmartPhone on wheels’. Information may be presented both in-vehicle and externally and needs to be relevant, timely, consistent and useful. The challenge for designers – supported by standards and guidelines – is to provide the information and services demanded by drivers that are usable without causing unsafe distraction and overload. In-vehicle human factors have a number of important consequences for Road Network Operations, in particular:

  • when a Traffic Control Centre exchanges information with vehicles and drivers through Cooperative ITS
  • if the network operations include vehicle fleets equipped with information and communication systems, such as mobile safety patrols
  • to promote safer travel on their roads
  • when the objective is to achieve greater compliance with traffic laws

As well as information and entertainment, in-vehicle sensor, communications and processing technology can assist drivers by providing advice and warnings concerning the vehicle’s immediate environment. These warnings have to be perceived, understood as relevant, and acted upon appropriately if they are to be effective. Guidelines in this area are now emerging.

Driver error is consistently identified as a contributory factor in over 90% of vehicle crashes. Better design of the driver interface has the potential to keep the driver “in-the-loop” whilst increasing safety. Additionally, many vehicles now include ITS that provide automation of specific elements of the driving task. Systems can even be designed to intervene in vehicle control to avoid or mitigate an impending collision. Nevertheless, usability issues around how the vehicle ‘feels’ and responds, and how control is partitioned between the vehicle and the driver, are crucial to achieving driver trust, acceptance and adoption. The RESPONSE Code of Practice provides at least some guidelines in this emerging area and further research is underway. 

It is good practice for new ITS vehicle applications or in-vehicle information and communication products to be simulated and trialled with users to understand better the interaction between them and any consequences

There are many international regulations on vehicle design and many standards and guidelines relating to information and communication systems (ICT) and warning and assistance systems.

Vehicle Regulations

A considerable volume of international regulation exists in relation to design requirements for motor vehicles that aim to ensure that technology within vehicles can be used safely. The United Nations Economic Commission for Europe’s (UNECE) Transport Division provides secretariat services to the World Forum for Harmonization of Vehicle Regulations (WP.29). The World Forum provides the regulatory framework for technological innovations in vehicles to make them safer and to improve their environmental performance. There is also a range of international law that affects drivers’ interaction with their vehicles and ITS. In Europe these take the form of Directives from the European Commission. In the US, there are both national and state laws on ITS human factors issues such as hand-held phone use and texting while driving.

information and communication systems

International Standards

Although not legally binding, international standards provide process, design and performance advice. The following are the main international working groups in areas relevant to vehicle design and usability:

  • ISO TC 22 SC13 WG8 covering basic standards for human factors design of in-vehicle systems
  • ISO TC 204 WG14 concerning vehicle and cooperative services (and some interface issues) including, for example, Lane Departure Warning and automatic Emergency Braking Systems
  • ISO TC 204 WG17 concerning nomadic and portable devices for ITS services
  • A wide range of standards covering visual and audible driver interfaces and dialogue management have been published.

Much of the knowledge from these standards has been incorporated in design guidelines and codes of practice. (See  ITS Standards)

European Statement of Principles

The European Commission (EC) has supported the development of a document called the ‘European Statement of Principles on HMI’ (referred to as ESoP) which provides high-level HMI design advice (EC 2008). As an EC Recommendation it has the status of a recommended practice or Code of Practice for use in Europe. It also contains 16 Recommendations for Safe Use (RSU), which build on Health and Safety legislation by emphasising the responsibility of organisations that employ drivers to attend to HMI aspects of their workplace. Adherence to the RSU is likely to promote greater acceptance of technology by drivers.

The design guidelines of the ESoP comprise 34 principles to ensure safe operation whilst driving. These are grouped into the following areas: Overall Design Principles, Installation Principles, Information Principles, Interactions with Controls and Displays Principles, System Behaviour Principles and Information about the System Principles.

United States: Alliance and NHTSA

The US motor vehicle manufacturers have developed ‘Alliance Guidelines’ that cover similar, high-level, design principles as the ESoP. The Guidelines (Auto Alliance 2006) consist of 24 principles organised into five groups: Installation Principles, Information Presentation Principles, Principles on Interactions with Displays/Controls, System Behaviour Principles, and Principles on Information about the System.

The USA’s National Highway Transportation Safety Administration (NHTSA) has worked with automobile manufacturers and the mobile phone industry to develop a set of guidelines for visual-manual interfaces for in-vehicle technologies. These are based on the ESoP/Alliance guidelines and introduce some specific assessment procedures (NHTSA 2013). The NHTSA also plan to publish guidelines for portable devices and guidelines for voice interfaces.

Japan: JAMA

The Japanese Auto Manufacturers Association’s (JAMA) Guidelines consist of four basic principles and 25 specific requirements that apply to the driver interface of each device to ensure safe operation whilst driving. Specific requirements are grouped into the following areas: Installation of Display Systems, Functions of Display Systems, Display System Operation While Vehicle in Motion, and Presentation of Information to Users. Additionally, there are three annexes: Display Monitor Location, Content and Display of Visual Information While Vehicle in Motion, and Operation of Display Monitors While Vehicle in Motion.

Warning and Assistance Systems

Warning Guidelines

Guidelines on establishing requirements for high-priority warning signals have been under development for more than five years by the UNECE/WP29/ITS Informal Group (Warning Guidelines 2011). There has also been work in standardisation groups to identify how to prioritise warnings when multiple messages need to be presented – and one ‘Technical specification’ (TS) has been produced:

  • ISO/TS 16951: Road Vehicles – Ergonomic aspects of transport information and control systems – Procedures for determining priority of on-board messages presented to drivers

In addition, two Technical Reports are relevant that contain a mixture of general guidance information (where supported by technical consensus) and discussion of areas for further research:

  • ISO/PDTR 16352: Road Vehicles – Ergonomic aspects of transport information and control systems – MMI of warning systems in vehicles
  • ISO/PDTR 12204: Road Vehicles – Ergonomic aspects of transport information and control systems – Introduction to integrating safety critical and time critical warning signals

Guidelines for Driver Assistance Systems

To help promote driver acceptance of Advanced Driver Assistance Systems (ADAS), a key issue is ensuring controllability. This has been addressed through guidelines. Controllability is determined by:

  • the possibility, and the driver’s capability, to perceive the criticality of a situation
  • the driver’s capability to decide on appropriate countermeasures (such as overriding or switching off the system)
  • the driver’s ability to perform any chosen countermeasures (taking account of the driver’s reaction time, sensory-motor speed and accuracy)

Drivers will expect controllability to exist in all their interactions with assistance systems:

  • during normal use within system limits
  • at and beyond system limits
  • during and after system failures

The European project RESPONSE, has developed a Code of Practice for defining, designing and validating ADAS. The Code (outlined in the figure below)  describes current procedures used by the vehicle industry to develop safe ADAS with particular emphasis on the human factors requirements for ‘controllability’.

Overview of the RESPONSE code of practice for design of in-vehicle information and assistance systems

Another European project, ADVISORS has tried to integrate the RESPONSE Code within a wider framework of user-centred design taking account of the usability of information, warning and assistance systems. The Intelligent Transport Systems (IHRA-ITS) Working Group of the International Harmonized Research Activities – is developing a set of high-level principles for the design of driver assistance systems (IHRA-ITS 2012).


Reference sources

RESPONSE (2009) Code of Practice for the design and evaluation of ADAS (accessed 23 October 2012).

Cotter, S., Hopkin, J. and Wood, K. (2007). A Code of Practice for developing advance driver assistance systems: Final report on work in the RESPONSE 3 project. Transport Research Laboratory PPR175 ISBN 1-84608-865-8 ISSN 0968-4093.

Cotter, S., Stevens, A., Mogilka, A. and Gelau, C. (2008). Development of innovative methodologies to evaluate ITS safety and usability: HUMANIST TF E. Proceedings of European Conference on Human Centred Design for Intelligent Transport Systems. 3–4 April 2008, Lyon, France. ISBN 978-2-9531712-0-4. (accessed 23 October 2013).

European Commission. 2008 ‘Commission Recommendation of 26 May 2008 on Safe and Efficient In-Vehicle Information and Communication Systems; Update of the European Statement of Principles on Human-Machine Interface,’ 2008. (accessed 23 October 2013)

IHRA-ITS. 2012. Design principles for ADAS 23 October 2013).

NHTSA. 2013 Visual-manual NHTSA driver distraction guidelines for in-vehicle electronic devices (accessed 30 April 2013).

Stevens, A., Burnett, B. and Horberry, T. J. (2010). A reference level for assessing the acceptable visual demand of in-vehicle information systems. Behaviour and Information Technology. Vol. 29, Issue 5: 527–540, Sept.

Warning guidelines from UNECE ITS informal Group (2011) (accessed 23 October 2012).

UMTRI Telematics guidelines collection (Accessed 23 October 2013)