HMI Design in the MaaS Era — The Importance of UX Design

12 min readMay 10, 2023

This is a discussion* of HMI design in the MaaS era. This section summarizes MaaS in the automotive industry, HMI design in the automotive cockpit, and the role of UX design in the manufacturing process.

What is MaaS in the automotive industry?

MaaS (Mobility as a Service) is an initiative that allows people to use their smartphones to make separate payments and complete procedures for each mode of transportation, whereas in the past this was done separately for each mode of transportation. This will integrate transportation services and make DX (Digital Transformation) an urgent priority. For users in particular, the ability to perform complicated procedures such as reservations and payments all at once via smartphone is a revolution in the field of transportation. Furthermore, “3th transportation” means such as electric kickboards and delivery robots are also attracting attention for their last-mile development.

Meanwhile, 4 keywords are trending in the automotive industry: CASE (connected, automated, shared, and electric). This means that each of these areas is not independent of each other, but rather is a trend that will be adopted sequentially depending on the generation, car model, model, etc. In other words, we can understand these as technology areas that will be incorporated into automobiles in the future. In other words, they can be understood as technology areas that will be incorporated into automobiles in the future. As a typical example of connectedness, the integration of smartphones is expected, and the global trend toward decarbonization includes the spread of EVs (electrification) and energy management, known as V2X (Vehicle-to-everything), which is also attracting increasing interest.

An example of an automaker’s approach is, first of all, General Motor’s “OnStar”. OnStar provides car owners with support services such as maps and navigation via a smartphone app. Second, Cruise is developing an unmanned, self-driving cab service, which can be reserved and used via a smartphone app. India’s ZoomCar matches time and users via a smartphone app so that other people can use the car when you are not using it.

MaaS in the automotive industry does not simply refer to vehicles, technologies, or functions, but to services that facilitate people’s mobility. That is why it is important to think from the user’s perspective. For example, “ZOOX,” an unmanned, self-driving vehicle being developed, is characterized by its design in which passengers face each other without a driver’s seat. This indicates that the car is not changing its shape with automated driving technology, but rather its design is changing so that passengers can enjoy their private space without the driver. Cars continue to evolve in response to service.

HMI design in cockpits in the automotive industry

Next, let’s look at HMI (Human Machine Interface) design in the automobile cockpit. Compared to the latest EVs, the cockpit of a conventional car may look legacy with lots of buttons. Research indicates that there are more than 100 functions, but these can be very difficult to master while driving.

Designs that focus solely on functionality tend to be button-heavy, like the cockpit of an aircraft. What is important is the perspective of how the user (driver) uses these functions. For example, what factors are involved in the act of “opening a window”? For example, if it is hot inside the car or if the driver wants to look outside, people make decisions based on the location and condition of the car as well as information from the outside and use these functions. Based on this, it is clear that one function is not necessarily one action, but rather multiple pieces of information that lead to an action. In other words, it is important to consider the action as the center of the function, rather than the function as a unit.

Balance between software and hardware

Software is superior in how it handles a great deal of information. A typical example is a car with a dashboard (monitor) that not only controls the car, but also manages the car’s position, status, and external information all in one place.

However, opinions on the software-oriented approach can be divided, with Sang Yup Lee, Hyndai’s design lead, stating, “We have frequently used physical buttons, and safety-related buttons must be hardware. (*). However, do users (drivers) really want to be in a situation where there are many buttons lined up, like in an aircraft cockpit?

In the latest EV cockpits, the balance between software and hardware has been carefully considered. For example, the Nissan “ARIYA”, which the author was involved in the development of, uses a 12.3-inch horizontal display, and the meter cluster and infotainment system are integrated in software. At the same time, tactile physical buttons are used for safety-critical switches such as HVAC, and a voice control function is available while driving. These are designed after conducting the design study described below to verify the actual actions required by the driver and the necessary operations, and to determine the extent to which they can be controlled by software.

A group of displays surrounding the driver

What features does the automotive industry want to see in the next generation cockpit, and what does AI indicate are three key areas: seamless connectivity, human-centered design, and flexible interiors? Let’s take a look at how automakers are addressing seamless connectivity in particular.

LUCID’s “LUCID Air” electric car is a good example of how multiple displays are seamlessly connected and intuitively operated. Created by designers involved in Apple’s automotive development, the large horizontal display is located in front of the steering wheel, while the vertical display is positioned in the console area. Mercedes-Benz’s “EQS HyperScreen” also attracted attention with its integrated multi-screen system. Mercedes has developed a system called “MBUX,” which can also be voice-controlled with “Hi Mercedes! Furthermore, the “AFEELA” prototype from Sony Honda Mobility, a Japanese manufacturer, does not have a vertical display in the console area, but features a large horizontal display that extends to the front of the passenger seat and includes mirrors on both sides in an integrated design.

These examples show that horizontal displays extending to the passenger seat and vertical displays extending to the console are typical of a luxury cockpit. The design that wraps the driver in the display is conspicuous. This concept of emphasizing the software that is displayed on the display is called “SDV (Software Defined Vehicle). It means redefining the functions of a vehicle through software. By increasing the number of parts that can be updated based on OTAs, we are aiming for an evolution similar to that of smartphones.

Mobile Tech Giant Trends

In the smartphone world, Apple’s “iOS” and Google’s “Android” are the major platforms, but in the automotive industry, there are also cars equipped with “Android Automotive (Car OS)” developed by Google. The Volvo Group’s “Polestar 2” is a typical example. Conventional OSs for automobiles have mainly been Linux or proprietary OSs, but recently there has been a trend to deploy OSs for smartphones in automobiles as well. In line with this trend, “Android” has been adopted in the latest electric vehicle SUV “EX90” announced by the Volvo Group.

In addition to Android Automotive, which is the Car OS, Google’s “Android” also offers the “Android Auto” smartphone application. This is used by launching the “Android Auto” application on one’s own smartphone and mirroring it to the car’s display. Since there is some overlap with the infotainment system provided by the car manufacturer, this may be viewed cautiously by the car manufacturer.

Apple likewise offers a mirroring smartphone app called “CarPlay”, a concept that extends to all of the car’s displays, not just the infotainment system, in 2022.

This rise of mirrored apps is of interest worldwide. A 2022 white paper by Germany’s HERE Technolgoies and ABI Research warns that carmakers’ navigation systems are outdated and difficult to use and will shift to mirroring. The solution, of course, is to improve the software so that an easy-to-update system can be used in older cars.

As of April 2023, GM has announced the phase-out of CarPlay, while Tesla and Rivian have announced enhancements to their infotainment systems in exchange for banning CarPlay.

From Driver-Centric to Passenger-Centric

Let’s change the perspective a bit. The figure contains 6 quadrants: luxury at the top, minimalist at the bottom, driver-oriented on the right, and passenger-oriented on the left. Here are some typical examples in each.

figure: 6 quadrants

Citroen’s “Ami” has only the smallest-sized meter display and is designed on the premise that you can stand your smartphone on it. In Japan, TOYOTA’s “C+pod” is a similar compact car concept, but you will not find a shape that assumes you can stand your smartphone on it. The design is very simple, as a minimum sized display is all that is needed for displaying with a mirroring application.

Given the premise of automated driving, we are now in the world of robo-taxis, and the traditional cockpit has virtually disappeared. For example, the “e-Palette” that drove in the Tokyo Olympics has no cockpit, but only a vehicle status monitor and an around-the-perimeter monitor. There are physical switches for emergency stop and door opening/closing, but no other buttons. Similarly, the “Boldly” self-driving bus scheduled to run at the 2025 Kansai-Osaka Expo has no cockpit. The vehicle’s status monitor is located on a pillar, and is controlled by a controller that is used when a person is assisting the driver. The controller is the same as a video game controller, so it can be operated just like a game.

The interior of the “Zoox” automated vehicle, which falls into the lower left quadrant, also has no cockpit. Passengers sit facing each other, and there is only a touch panel at the hand of the sofa.

Looking to the future, one can imagine a lot of advanced features, but it is not realistic to try to make every single one of them a physical button. First of all, users will not be able to use them all. In the driverless era, it is important to remember that the user of an automobile is not the driver who drives, but the passenger (passenger, passenger) who rides in the car. Therefore, it is important that HMIs for automobiles be passenger-centric.

Role of UX design in the manufacturing process

In order to advance the design process, the manufacturing process must be reviewed. In a traditional legacy company, each function is organized and the process proceeds in order, aiming for a stable supply. However, in the recent design industry, the method of making and verifying prototypes before the design process has become widespread. In other words, when there are processes such as planning, design, and development, prototypes are designed and developed during the planning stage, and then put through verification. In addition, in that verification, the product is used by actual subjects to obtain useful feedback before proceeding to the original design process.

This requires a cross-functional team that spans the organization, and requires consistent consideration of concept and evaluation criteria.

Designing before the original design process may differ from the traditional organization and process, but it means planning first how the product will be used, rather than designing after what is to be created has been decided. In other words, it is a process of understanding the user’s situation (scene) and considering what functions are necessary. This is called UX design.

The downside of prioritizing functionality in development

Looking at the efforts of various automobile companies, the scene may not be fully considered.

For example, BMW’s “iVisionDee,” a horizontal display that works in conjunction with a HUD (heads-up display), also displays a variety of information on the windshield, but there are obvious concerns about distractions that impede driving. In fact, if a survey were conducted in which subjects were asked to use the system, responses such as “I don’t see it” or “I can’t see it” would be obtained, making it difficult to concentrate on driving. This is an example of development that prioritizes functionality.

In addition, Nissan’s “EasyRide” vehicle, an automated driving demonstration experiment, had a large monitor installed in the back seat, but because it was not properly linked to the passenger’s smartphone, the information displayed was one-sided. The monitors in the back seat, which have become common in cabs these days, are nothing more than advertisements if they are not properly linked to the information that the passenger wants to know or needs.

Until now, cabs have had a communication system in which passengers are asked where they are going after they get in the cab, but from now on, information will be shared in advance, and the ride experience will begin with a “You know where you are going, right? The ride experience will begin with “You know where you are going, don’t you? The same can be said for other vehicles as well, and it is necessary to properly verify what information is needed by the passenger and when it is needed.

A special experience of boarding

In today’s world of constant smartphone use, the act of boarding a train is part of our daily lives. We are always looking at our smartphones, but do we really want to have to look at a special monitor when we get on the train or airplane?

In fact, when I think about what I do on trains and airplanes when I am not driving, I look at my smartphone. Not only do I enjoy the news, which I watch on a regular basis, but I also enjoy entertainment such as work information and videos.

Recently, we can also see efforts by automobile companies that are shifting their focus to entertainment: holoride, a spin-out from BMW, is offering a game that uses MR goggles, in which the VR world unfolds in conjunction with real-world gravity, inertia, speed, etc. In addition, the VR world is also being developed in conjunction with the real-world gravity, inertia, speed, etc. In addition, “LG OMNIPOD”, which was presented at CES, even had a concept in which the entire interior is LED and offers content that allows passengers to do fitness activities while driving automatically. Mini’s “ACEMAN,” which is linked to the entire interior space, is also remarkable for its display, illumination, and materials.

New Mobility Services and Spatial Design

The major difference between automobiles and trains or airplanes is the availability of private space. If information can be provided on a monitor in front of you, dedicated content is one way to provide information, but in today’s world, personal smartphones are expected to play a role in providing information. For example, it may be possible to obtain more useful information by linking to one’s own smartphone, as in the case of mirroring applications.

In addition, if a space can be provided as a private room, it is important to consider and design the activities possible in that space. Whether it is a partition in a ramen shop for one person, a private room in a manga café, or hotel accommodations, future HMI design will require the design of spaces that are used for specific purposes.

The Road Traffic Law will be revised in April 2023 to allow “fully automated driving under specific conditions,” equivalent to Level 4 automated driving, and new mobility services will be deployed. We can expect that MaaS will improve convenience, and that new spatial design will significantly change the experience of mobility. The automotive industry will move toward a sustainable and convenient future as processes that involve users become more prevalent.

  • This article is based on a lecture given at a seminar organized by the Technical Information Association of Japan. He also contributed to the June issue of the monthly automotive industry magazine MATERIALSTAGE.
  • The presentation deck is available on SpeakerDeck.

*This article is reprinted from a personal blog.




Design at TIER IV, designing for Software-Defined Autonomous Mobility.