(Source: Syda Productions/ stock.adobe.com)
Vehicles have evolved remarkably over the past two decades, continually offering new features and functions. The ongoing transformation has led to the development of the digitalized modern vehicle—an expansive software platform in its own right. These digitalized vehicles present a challenge for usability, as a product’s complexity often reduces its ease of use. More than ever, human-machine interface (HMI) designers seek consumer feedback to inform successful interface designs.
Every element a consumer sees, touches, or hears when interacting with a vehicle, from an exterior door handle to a dashboard touchscreen, is a meticulously crafted aspect of the vehicle’s HMI design. These interfaces must accommodate a uniquely diverse user base, prioritize safe use with minimal distraction, and adapt to meet global user expectations. As technology evolves, designing interfaces for vehicles—some of the most complex consumer products—continues to pose new challenges.
Producing a captivating vehicle with intuitive interfaces starts with consumer engagement. From the earliest stages of development, designers must perceive user needs—an exceptional challenge for the automotive field. Whereas industries like medical product development often have a specific user, such as a highly trained surgeon operating a robotic surgical system, the automotive user group is extremely broad, encompassing almost anyone with a driver’s license. At one end of the spectrum is the novice driver, possibly a teenager, who is experiencing driving for the first time and for whom everything is new. At the opposite end is the seasoned driver, who is equipped with decades of driving expertise and deep-seated beliefs about how the vehicle should operate.
To address this challenge, designers and researchers must frequently present concepts and prototypes to a wide range of users and workshop ideas. Variations of this feedback loop occur throughout the development life cycle:
In the past, consumer research was undervalued and less integrated into the design process, resulting in a limited understanding of user needs. Downstream, this often resulted in companies discovering they had developed an unpopular feature or an ineffective interface, necessitating late and costly modifications. Seeking the appropriate feedback at the right time helps designers develop a well-received product with seamless interfaces.
Another significant design consideration unique to automotive interfaces is that interacting with the interface is a “secondary task” to driving or parking. While devices like phones or computers typically absorb the user’s full attention, automotive interfaces entail brief and sometimes blind operations while drivers focus on the road ahead. Developers can leverage many technologies in their interface designs to help enable quick and easy access to features and functions.
Like many other industries, the automotive market is trending toward digital-forward interfaces. The cost-effectiveness of substituting sophisticated software for bulky hardware is an attractive prospect for manufacturers. In contrast, consumers prefer the comfort and blind use of physical touchpoints, such as audio and climate hard buttons, shifters, and steering wheel controls.
Designers are balancing the needs of both groups by using smart automation to enhance vehicle intelligence and reduce physical controls. For example, nearly all vehicles are now equipped with photoresistors that detect low-light conditions and activate headlights automatically. Other vehicles engage headlights immediately upon vehicle ignition.
Automation is even becoming integrated into driving itself, as demonstrated by capabilities like hands-free driving. To promote driver attentiveness while using this feature, camera and infrared sensors positioned throughout the cabin monitor the driver’s gaze. Additional sensors, such as capacitive or resistive versions, are integrated into the steering wheel to verify the presence of the driver’s hands on the wheel. If the driver seems to lose focus, the driver state monitoring system can alert the driver or disable the hands-free driving feature.
Ultimately, integrating HMI technologies like digital interfaces, physical touchpoints, and automation into vehicles allows users to comfortably and safely engage with their vehicles’ systems while driving.
The global market is an additional design consideration for automotive HMI, requiring designers to consider the diverse users and contexts in which consumers worldwide may interact with their vehicles. For example, a vehicle purchased in China is often a family decision involving three generations—children, parents, and grandparents. Whereas HMI design for users in the United States emphasizes the driver’s interface, HMI design for users in China is more comprehensive, encompassing controllable features and functions for passenger and rear seat positions. As an illustration, a single elongated dashboard display could seamlessly transition from driver-only functionality to also serve the front passenger, incorporating technology to help manage that person’s preferences and those of passengers in the rear seats.
Designers must also take into account how driving conditions vary from location to location. A bustling city with congestion, traffic signals, motorcycles, and pedestrians presents a more complex driving environment than a suburban area with quieter streets. With so much visual noise already in front of drivers, designers must consider the added distraction of features like a heads-up display that projects into the driver’s line of sight.
Furthermore, interface developers need to adhere to local norms and expectations. For instance, users in China often anticipate that vehicle touchscreens will provide access to many of the same apps available on their phones. Overall, vehicles designed for a global user base require interfaces crafted with cultural and geographical considerations in mind.
As the automotive industry advances toward interconnected vehicle architecture, designers can develop more comprehensive systems that communicate between functions rather than requiring users to manage individual modules separately. By prioritizing consumer input throughout the process, designers can strike the delicate balance between digital interfaces, physical touchpoints, and predictive automation required for a successful product. At the same time, designers must make interfaces adaptable to the diverse expectations of a global audience. Vehicle interfaces that embody these characteristics are key to producing a vehicle consumers can fall in love with.
Julee Henry, a human factors specialist, leverages her deep understanding of user research and user-centered design to enhance product development. With a master’s degree in human factors engineering and a decade of experience designing HMI technologies for the global automotive and medical product markets, Julee is a leading subject matter expert in the field of HMI. Now at Emergo by UL, Julee is part of an expansive global team of user researchers, designers and human factors specialists helping manufacturers make safer, more intuitive and competitive products that consumers love.