Will Pedestrians Be Able to Tell What a Driverless Car Is About to Do?

A self-driving Ford Fusion hybrid car is test driven, Thursday, Aug. 18, 2016, in Pittsburgh.

A self-driving Ford Fusion hybrid car is test driven, Thursday, Aug. 18, 2016, in Pittsburgh. Jared Wickerham/AP

For self-driving vehicles to succeed, they’ll have to earn the trust of walkers, joggers and bicyclists.

A fully autonomous self-driving car doesn’t really need a steering wheel, or a rearview mirror, or even windows to get where it’s going. But the first models are still likely to have them. (And not just because such features could be legally required.)

In the coming years and decades, as the public decides how to feel about autonomous cars, the way self-driving vehicles appear will be arguably as important as how they function. And people, Americans in particular, have clearly defined expectations about what cars ought to look like.

“When we’re looking at new devices, you could make them anything, right? Any shape, any form,” said Robert Brunner, the industrial designer who worked for many years at Apple and now runs his own design studio. “But we’re also trying to get people to relate to and understand the technology.”

Self-driving vehicles, he says, should feel inviting and friendly, and should inspire confidence. The way to do this might be to follow Google’s lead, and make driverless cars cute. At the very least, Brunner told me, the ideal self-driving car probably shouldn’t be a “black menacing thing with lots of red lights.”

Engineers and designers will also have to take into account some of the new challenges that accompany driverlessness. For instance: How will self-driving vehicles communicate with human drivers, pedestrians and bicyclists? The use of blinkers, brake lights and hazard lights can be automated, surely, but there are many human gestures and cues that are a crucial part of how people navigate the roads—eye contact, the waving of a hand at an intersection—which a machine can’t precisely emulate.

“There are ways of drastically reducing the level of complexity of these systems and making them logical and understandable and reliable,” said Sam Arbesman, the author of "Overcomplicated: Technology at the Limits of Comprehension." “The problem is—because of the fact we build the new on top of the old—we aim for these really, really pristine constructions that are built with all these design practices and principles, but things cannot be perfect.”

A more slippery existential problem is that new ways for driverless cars to communicate with pedestrians will only work if people respond to them.

But getting people to respond to a new kind of design signal—just getting them to understand it in the first place—is iffy at best.

“People hate ambiguity and unpredictability,” said Chris Rockwell, CEO and founder of Lextant, a design consulting firm. “I don’t care if it’s your toaster or your car; if you’re confused, you’re not having a great experience. And if it acts in strange or unpredictable ways, it’s not acceptable.”

The trouble is, people are unpredictable. So designing new ways for machines to communicate with them isn’t exactly straightforward. Many ideas for new communications systems have been proposed—driverless cars might feature audible chimes, voice instructions or text displays to communicate their next moves—but few if any such systems have been tested.

“The ideas aren’t the problem; it’s raining ideas,” Rockwell said. “The challenge is really understanding what problem we’re solving. These are human systems, ultimately.”

“From our standpoint, autonomous vehicles and self-driving systems will happen,” he added. “It’s kind of an inevitability. But the challenge won’t be around the technology as much as it will be around the psychology. It’s going to be critical to gain trust—and that trust can be designed into these systems. Trust not only with the passengers but also the pedestrians outside.”

In an attempt to better understand how pedestrians might respond to self-driving vehicles, roboticists at Duke recently carried out an experiment that involved comparing the effectiveness of several different prototypes for vehicle-to-pedestrian communications. (They detailed their findings in a paper now under review for presentation at the Transportation Research Board’s annual meeting.)

The researchers used a van meant to look like a driverless vehicle, and outfitted it with a large display that could feature “walk” and “don’t walk” signals, as well as a numeric display of the speed at which the vehicle was traveling.

“The idea was that the participants would use the speedometer to determine whether it was safe to cross,” said Michael Clamann, a roboticist at Duke and one of the lead authors of the paper. “Reading ‘0’ would be the safest, but the objective was to provide a display that would indicate the vehicle was decelerating.”

As it turned out, most pedestrians ignored the new-fangled display, whichever iteration was used. Pedestrians were more likely to rely on “legacy behaviors”—like eyeballing an approaching car’s speed and inferring how quickly to dart across the street—rather than external displays.

“As we start the transition to driverless vehicles, designers need to be aware that people will rely on old habits when interacting with the new technologies,” Clamann said.

Part of the problem is that for a display to be useful, the text has to be huge. And even when it’s big enough, a lot of people seemed to ignore it anyway. To be visible from a distance of 100 feet, a single letter would need to be six inches tall and nearly four inches wide.

“So a screen designed to display a simple message like ‘safe to cross’ without scrolling horizontally would require a screen at least 47 inches wide,” the researchers wrote. From 200 feet away, the same message would have to be over 100 inches wide; wider than most cars.

“Right now, a pedestrian communicates with a driver. In the future, this communication will be between a human and a machine, which is an area that requires exploration and careful design decisions,” Clamann told me. “We learn from birth how to communicate with other people, but communicating with machines is a very different skill. We need to make sure the displays and signals work as intended before we release them.”

The team at Duke found no significant differences between any of the 35 different displays they tested, meaning each was “as effective as the current status quo of having no display at all.”

Nearly 5,000 pedestrians were killed by cars in 2014 in the United States alone, according to data from the National Highway Traffic Safety Administration. Driverless cars—with their famously sterling safety records—may be able to reduce those statistics significantly.

Still, about half of the pedestrian deaths in the 10-year period ending with 2014 occurred because the pedestrian ran into the road, failed to yield to a vehicle with the right of way, or otherwise crossed the street improperly, the Duke researchers said.

Even the best-programmed autonomous cars will be unable to prevent every pedestrian death unless those vehicles can find a way to prompt safer pedestrian behaviors. In other words, with self-driving cars facing a critical test period for the public’s trust, the status quo isn’t going to be good enough.

X
This website uses cookies to enhance user experience and to analyze performance and traffic on our website. We also share information about your use of our site with our social media, advertising and analytics partners. Learn More / Do Not Sell My Personal Information
Accept Cookies
X
Cookie Preferences Cookie List

Do Not Sell My Personal Information

When you visit our website, we store cookies on your browser to collect information. The information collected might relate to you, your preferences or your device, and is mostly used to make the site work as you expect it to and to provide a more personalized web experience. However, you can choose not to allow certain types of cookies, which may impact your experience of the site and the services we are able to offer. Click on the different category headings to find out more and change our default settings according to your preference. You cannot opt-out of our First Party Strictly Necessary Cookies as they are deployed in order to ensure the proper functioning of our website (such as prompting the cookie banner and remembering your settings, to log into your account, to redirect you when you log out, etc.). For more information about the First and Third Party Cookies used please follow this link.

Allow All Cookies

Manage Consent Preferences

Strictly Necessary Cookies - Always Active

We do not allow you to opt-out of our certain cookies, as they are necessary to ensure the proper functioning of our website (such as prompting our cookie banner and remembering your privacy choices) and/or to monitor site performance. These cookies are not used in a way that constitutes a “sale” of your data under the CCPA. You can set your browser to block or alert you about these cookies, but some parts of the site will not work as intended if you do so. You can usually find these settings in the Options or Preferences menu of your browser. Visit www.allaboutcookies.org to learn more.

Sale of Personal Data, Targeting & Social Media Cookies

Under the California Consumer Privacy Act, you have the right to opt-out of the sale of your personal information to third parties. These cookies collect information for analytics and to personalize your experience with targeted ads. You may exercise your right to opt out of the sale of personal information by using this toggle switch. If you opt out we will not be able to offer you personalised ads and will not hand over your personal information to any third parties. Additionally, you may contact our legal department for further clarification about your rights as a California consumer by using this Exercise My Rights link

If you have enabled privacy controls on your browser (such as a plugin), we have to take that as a valid request to opt-out. Therefore we would not be able to track your activity through the web. This may affect our ability to personalize ads according to your preferences.

Targeting cookies may be set through our site by our advertising partners. They may be used by those companies to build a profile of your interests and show you relevant adverts on other sites. They do not store directly personal information, but are based on uniquely identifying your browser and internet device. If you do not allow these cookies, you will experience less targeted advertising.

Social media cookies are set by a range of social media services that we have added to the site to enable you to share our content with your friends and networks. They are capable of tracking your browser across other sites and building up a profile of your interests. This may impact the content and messages you see on other websites you visit. If you do not allow these cookies you may not be able to use or see these sharing tools.

If you want to opt out of all of our lead reports and lists, please submit a privacy request at our Do Not Sell page.

Save Settings
Cookie Preferences Cookie List

Cookie List

A cookie is a small piece of data (text file) that a website – when visited by a user – asks your browser to store on your device in order to remember information about you, such as your language preference or login information. Those cookies are set by us and called first-party cookies. We also use third-party cookies – which are cookies from a domain different than the domain of the website you are visiting – for our advertising and marketing efforts. More specifically, we use cookies and other tracking technologies for the following purposes:

Strictly Necessary Cookies

We do not allow you to opt-out of our certain cookies, as they are necessary to ensure the proper functioning of our website (such as prompting our cookie banner and remembering your privacy choices) and/or to monitor site performance. These cookies are not used in a way that constitutes a “sale” of your data under the CCPA. You can set your browser to block or alert you about these cookies, but some parts of the site will not work as intended if you do so. You can usually find these settings in the Options or Preferences menu of your browser. Visit www.allaboutcookies.org to learn more.

Functional Cookies

We do not allow you to opt-out of our certain cookies, as they are necessary to ensure the proper functioning of our website (such as prompting our cookie banner and remembering your privacy choices) and/or to monitor site performance. These cookies are not used in a way that constitutes a “sale” of your data under the CCPA. You can set your browser to block or alert you about these cookies, but some parts of the site will not work as intended if you do so. You can usually find these settings in the Options or Preferences menu of your browser. Visit www.allaboutcookies.org to learn more.

Performance Cookies

We do not allow you to opt-out of our certain cookies, as they are necessary to ensure the proper functioning of our website (such as prompting our cookie banner and remembering your privacy choices) and/or to monitor site performance. These cookies are not used in a way that constitutes a “sale” of your data under the CCPA. You can set your browser to block or alert you about these cookies, but some parts of the site will not work as intended if you do so. You can usually find these settings in the Options or Preferences menu of your browser. Visit www.allaboutcookies.org to learn more.

Sale of Personal Data

We also use cookies to personalize your experience on our websites, including by determining the most relevant content and advertisements to show you, and to monitor site traffic and performance, so that we may improve our websites and your experience. You may opt out of our use of such cookies (and the associated “sale” of your Personal Information) by using this toggle switch. You will still see some advertising, regardless of your selection. Because we do not track you across different devices, browsers and GEMG properties, your selection will take effect only on this browser, this device and this website.

Social Media Cookies

We also use cookies to personalize your experience on our websites, including by determining the most relevant content and advertisements to show you, and to monitor site traffic and performance, so that we may improve our websites and your experience. You may opt out of our use of such cookies (and the associated “sale” of your Personal Information) by using this toggle switch. You will still see some advertising, regardless of your selection. Because we do not track you across different devices, browsers and GEMG properties, your selection will take effect only on this browser, this device and this website.

Targeting Cookies

We also use cookies to personalize your experience on our websites, including by determining the most relevant content and advertisements to show you, and to monitor site traffic and performance, so that we may improve our websites and your experience. You may opt out of our use of such cookies (and the associated “sale” of your Personal Information) by using this toggle switch. You will still see some advertising, regardless of your selection. Because we do not track you across different devices, browsers and GEMG properties, your selection will take effect only on this browser, this device and this website.