Announcement: Tuhin Diptiman to discuss NHTSA visual-manual guidelines

Implications of NHTSA Visual Manual Guidelines to the Design and User Experience of In-vehicle Interfaces

Tuhin Diptiman

Human Factors Group

Toyota Technical Center

Ann Arbor, USA


NHTSA released visual manual guidelines in 2013 to limit the potential of distracted driving caused by in-vehicle telematics by loosely tying together guidelines published by the Alliance and JAMA, and adding additional parameters such as “per se lockouts”. While the implications to each automotive OEM may vary greatly, these guidelines have the potential to severely limit vehicle cockpit design and user interfaces which are at the core of the driving experience. NHTSA plans to reign in the automakers by increasing the scope and depth of vehicle systems by limiting non-driving tasks such as telematics, navigation, and entertainment to lower than the levels used by the Alliance and by including driving related tasks such as cruise and climate controls.

A caveat – most experts agree that a severely restricted in-vehicle interface will further push the driving population to use the handheld devices which have been documented to be inappropriate for use while driving but which allow for an unrestricted user experience. While the unintended safety implications of a heavily restricted in-vehicle interface and an unrestricted handheld interface is as yet unknown, this area of driver distraction will continue to be the forefront of research and debate for quite a while to come.


Tuhin Diptiman completed his BSE and MSE in Industrial Engineering from the University of Iowa in 2002 and was a member of the Industrial Engineering Honor Society. His research involved a preliminary investigation in measuring emotion using physiological measures. After completing his thesis he joined the Crash Avoidance Metrics Partnership (CAMP) a consortium of Ford, GM, Toyota, Nissan and the US Department of Transportation and worked as a research engineer on the prestigious Driver Workload Metrics (DWM) project to study surrogate metrics to identify, measure and mitigate driver distraction.

He joined Toyota in 2008 to support Toyota’s on-going expansion of driver distraction research and human-machine interface (HMI) development in the US. His primary responsibility is to ensure that all Toyota navigation and telematics systems development for the US market are designed in conformance with Toyota’s guidelines which are based on the Alliance guidelines. As a human factors engineer he has played a significant role in supporting the development of interfaces related to multi-function displays, steering switches and navigation/telematics systems. His was instrumental in creating the HMI for the Toyota Entune Apps system, the first of its kind for any automotive OEM. He has been instrumental in shaping Toyota’s policy and on-going research on driver distraction and currently he is leading Toyota’s interpretation of the NHTSA visual manual guidelines and investigating its impact on product design and development.