Crafting trust: the design of safe autonomous vehicles

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EXECUTIVE SUMMARY:

Autonomous vehicles (AVs) stand at the intersection of modern transportation and cutting-edge AI technology. Their promise: to revolutionize our roads and redefine our travel experiences. Yet, lurking beneath the horizon of this futuristic vision, skepticism about their safety persists, potentially stalling their mass adoption.

Central to this exploration is the vehicle’s exterior design, a silent communicator of safety not only for those inside but also for pedestrians and cyclists on the streets. To dive deeper, authors engaged the minds of senior figures from the automotive and transport design world. Their insights unveiled a fascinating duality. While there’s a consensus on certain design elements, a tug-of-war emerges when balancing the safety assurances for passengers and bystanders.

Interestingly, many of these design inclinations are rooted in the world of traditional vehicles. This raises questions about their applicability and relevance in the brave new world of AVs.

This study lays the groundwork, presenting a curated list of design features. The ultimate goal is to equip design professionals with clear, actionable insights, ensuring design choices are grounded in both art and objectivity.

Key Takeaways:

Safety perceptions differ for passengers and bystanders.
Vehicle architecture, form, and graphics play a key role in shaping trust and safety.
The design isn’t just aesthetics; it shapes perceptions of safety and trust.
Lighting and color choices in AVs play crucial roles in shaping trust.
The design landscape for AVs is ever-evolving, with a balance between passengers and bystanders being paramount.

Unveiling the Nature of Design for Perception of Safety

In the age of autonomous vehicles (AVs) powered by the Artificial Intelligence, the horizon of transportation promises a safer, greener, and more sustainable journey. Gone are the days when a driver’s hands dictated the motion of wheels. Instead, the romance of a future beckons where passengers revel in leisure and productivity, free from the obligations of the wheel. Yet, even within this promising vision, the uncertainty remains. Can the world embrace a drive void of human touch? Trust and safety emerge as potent ingredients in this equation.

In this digital era, we often focus on screens and buttons, but the real look of autonomous vehicles (AVs) hasn’t been fully explored. But when it comes to self-driving cars, it’s their look and feel that really matter. They’re not just cars; they’re our peek into the future. Their design tells us if they’re safe and can be trusted. Much like an artist’s brush strokes or a designer’s motif that captivates and defines an object’s essence, the aesthetics and design of an AV play a monumental role in sculpting our emotions and decisions. It’s a timeless dance – the allure of “Sportiness,” the promise of “Durability,” or the allure of “Premiumness” - elements that have been long cherished in the annals of automobile design.

Diving deeper, this research introduces the ‘Data-Informed-Design’ (D-I-D) approach. It’s a path to merge intuition with data, to guide designers in creating AVs that resonate with human trust and pave the way for a widespread embrace.

Bridging the Gap with Information Asymmetry

Current car designs are mainly based on what designers already know. But with self-driving cars, there’s a new challenge. Designers are trying to match what they think the car should be like with what future passengers might expect. Because most people haven’t interacted with these cars, there’s a knowledge gap. Think of it like a conversation: the designer sends a message through the car’s design, and the customer receives it. Right now, the message isn’t always clear because designers aren’t fully sure of what customers want, and customers might not understand all the cool features the car offers.

Figure 1. Knowledge gap and information asymmetry in the design of future autonomous vehicles

Method: Quest for True Aims

This study looks at how the design of self-driving cars can make people feel safe. Authors wanted to know which design features of the car’s design make people think it’s safe. They looked at this from two angles: how someone inside the car feels, and how someone outside, like a pedestrian or cyclist, feels when near it.

Design features in this study defined as: “..the result of a creative process that transform ideas and insights into products’ attributes and characteristics that are perceptible, distinctive, able to deliver value satisfying consumers’ desires and providing a sense of gratification in owning that item. Generally, design features are represented by physical and functional characteristics such as shape, color, material, texture, the purpose of the design, behaviors, and all the elements that play a role in the user experience. Design features define the characteristics and behaviors that contribute to the functionalities of a product.”

In the absence of any systematic taxonomy of design features, authors conducted a series of semi-structured interviews with senior automotive and transport designers and educators to develop an initial list of exterior design features deemed to be relevant in the context of future AV passengers and bystanders. Here they constrained the investigation to a specific AV typology and context. Specifically, the type of AV referred to in this study constituted a shared vehicle managed by a mobility service provider; SAE level 4 automation; no vehicle controls; small footprint 2-seater; forward facing seating arrangement; urban use in mixed traffic conditions; geofenced area of operation; and a maximum speed of 30 mph.”

The Dance of Design: Striking the Balance in Autonomous Vehicles

Setting the Scene

When asked about the foundational elements that would inspire feelings of safety in autonomous vehicles (AVs), designers were naturally inclined towards the passenger’s viewpoint. Words such as “stable”, “confident”, and “solid” frequently made their appearance. Yet, when the lens shifted to the bystander’s perspective, the ideal designs that felt safe for passengers often translated as potentially threatening. This presents a notable conundrum: do you appease the passenger or the pedestrian? While some pondered a harmonious middle ground, others worried about birthing a design that would satisfy neither. It’s evident that the notion of safety in AV design is not purely about aesthetics; it’s influenced by vehicle brand reputation, societal shifts, and even regional cultural nuances.

Peeling the Layers of Design

ARCHITECTURE:

Size Perception: People tend to see smaller cars as more vulnerable. Especially those compact city cars—they have their work cut out in looking tough.

Belt Line: Think of this as the line on a car’s side right below the windows. If it’s lower, passengers might feel more exposed, like sitting in an open basket.

DLO (Day Light Openings): This is the windowed area on a car’s side. Smaller windows might make passengers feel more protected, as if they’re in a cozy room. Bigger windows? More like being in an open space.

Pillars and Rails: These structures hold up the roof. If they look beefy, they make the car feel solid, like a fortress on wheels.

Wheels: Bigger wheels, especially when tucked neatly under the car, make it seem steady. But if they stick out, they might scare pedestrians. And that bit of the car extending beyond the wheels? If it’s short, the car seems well-grounded.

Wedge: It’s about the car’s side profile. If the front and back are even in height, it feels balanced. If not, the car seems like it’s leaning forward or backward.

Seating Height: Sitting higher feels safer and comfier. No wonder SUVs, with their elevated seats, are so popular!

Car Shapes: Modern AV (autonomous vehicle) designs often favor what’s known as a “one-box” style, sometimes referred to as monospace or monovolume. This design choice offers a seamless and spacious interior, allowing passengers more flexibility in how they use the space — think facing seats or room for activities beyond just driving. On the other hand, the “two-box” style divides the car into two distinct sections: the front area, which usually houses the engine and safety features, and the back section dedicated to passengers and storage. Some believe this design might offer an extra safety layer during collisions, a concept even those fond of the one-box design might consider.

FORM:

When it comes to vehicle design, those surveyed believed that the style and character of a vehicle plays a crucial role in how safe it appears. There’s a feeling that many of today’s car designs lean too heavily towards an aggressive look, which doesn’t fit the vision of a harmonious future of mobility. Ideally, a vehicle should strike a balance — not appearing too timid or overly aggressive. Local culture and target demographics can also influence this balance.

Take the Japanese “Kei” cars as an example. These mini cars, designed for Japan’s urban environments, are often tall and boxy, yet they convey a sense of stability through their design and proportions. These cars have a unique charm expressed through their exteriors, which could be influential for AV designs, though such charm might resonate differently across cultures. While a fierce look might give a sense of protection to an occupant, bystanders might prefer a friendlier design, showcasing the need to balance both viewpoints.

In essence, a car’s design should exude stability and sturdiness. Simple, geometric designs are often seen as safer compared to intricate ones. The ideal surface language for cars is gentle and welcoming, but they should also appear substantial, avoiding a look that’s too diminutive.like stiffness, softness, and wear-resistance – is needed. Furthermore, with a growing emphasis on sustainability, the investigation must also consider eco-friendly materials.

GRAPHICS:

Graphics play a crucial part in amplifying a vehicle’s sense of stability and trustworthiness. Many experts emphasized the strategic use of lights to enhance this perception. For instance, full-width lights can emphasize a car’s breadth, particularly vital for smaller autonomous vehicles (AVs). However, it’s essential to avoid positioning lights or other elements too high, as this could make the vehicle seem unstable. Another innovative idea? Using lights to make wheels look larger. It’s worth noting, though, that the trending move towards tinier lights might give cars a more impersonal look, taking away the human-like features that traditionally help connect vehicles with their users.

When it comes to color, it might not hold the same weight as form and structure in influencing perception, but it’s still noteworthy. Subdued, calm colors tend to be seen as safer compared to bright, flashy ones. For example, while white might come off as delicate, adaptive color technologies could offer promise, adjusting hues based on specific situations and cultural contexts.

Graphics also have a role in managing visibility. Drawing inspiration from public transport, the use of decals and blinds could strike the right balance between being visible, maintaining privacy, and not feeling too exposed – all contributing to feelings of safety. An interesting notion is the potential use of graphics to highlight safety features, like reinforced doors, offering AVs a distinct aesthetic touch.

Lastly, making AV-specific technologies like Lidar sensors visibly prominent might boost passengers’ confidence. They would have a clear view of the systems in place to ensure their safety. In fact, some AV designs have already started to showcase this tech as a design highlight, rather than hiding it.

Drawing Conclusions

This deep dive into the world of AV design showcased that the journey towards designing a universally “safe-feeling” AV is intricate, multi-dimensional, and far from complete. Design nuances in autonomous vehicles (AVs) play a pivotal role in user perception. To summarize:

Central to AV design is the conveyance of both stability and safety.
Strategic design aspects, like a lower belt line and reduced glass area, mitigate perceived vulnerability in smaller vehicles.
Wheel placement, vehicle stance, pillars, and cant rails enhance the perception of structural solidity.
Cultural design insights, exemplified by Japanese “Kei” cars, underline the need to balance global appeal and local preferences.
A focus on simplicity, approachability, and clean geometric designs reinforces the safety image of the vehicle.
As AV design evolves, it’s essential to merge aesthetics, user comfort, and perceived safety.

Disclaimer: This Future Insight is the adaptation of the original research article entitled: “Shaping Autonomous Vehicles: Towards a Taxonomy of Design Features Instilling a Sense of Safety” written by Cyriel Diels, Kostas Stylidis, Artur Mausbach & Dale Harrow. Originally published by Springer in “International Conference on Human-Computer Interaction. HCII 2022”

About this paper:

Diels, C., Stylidis, K., Mausbach, A., Harrow, D. (2022). Shaping Autonomous Vehicles: Towards a Taxonomy of Design Features Instilling a Sense of Safety. In: Stephanidis, C., Antona, M., Ntoa, S. (eds) HCI International 2022 Posters. HCII 2022. Communications in Computer and Information Science, vol 1583. Springer, Cham. https://doi.org/10.1007/978-3-031-06394-7_24

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