Enhancing Advanced Vehicles to Safely Handle Tricky Road Situations

High-tech cars must overcome safety challenges like encounters with pedestrians and railroad crossings.

September 24, 2019

ALEXANDRIA, Va.—Hybrid and electric cars are becoming more popular because they save energy and offer a quiet drive. But a federal regulation goes into effect next fall will require them to play sounds at certain speeds for pedestrian safety, reports The New York Times.

Because e-cars are so quiet, people often don’t hear them coming. But designing appropriate sounds is a complex undertaking, according to Joel Beckerman, founder of Man Made Music, which works with Nissan to address both safety concerns and maintain a brand identity.

“If we do our job in this kind of situation, then you don’t notice what we did at all,” Beckerman said. “It just becomes natural, it’s just a part of your life, it’s a part of your environment. When you get it wrong, that’s when people notice.”

While the advent of quieter hybrid and electric vehicles presents an opportunity to build sounds from scratch, there is a long history of sound design in the automotive industry. Muscle cars have their distinctive throaty growl. Harley Davidson motorcycles have that syncopated “potato-potato-potato” chug. (Yes, that’s really what they call it.)

In the case of hybrid and electric vehicles, the need for sound is about more than the user experience and safety. About 10 years ago, the National Highway Traffic Safety Administration found that hybrid electric vehicles were 35% more likely than those with internal combustion engines to be involved in a pedestrian crash. Hybrids were also 57% more likely to be involved in crashes involving bicycles.

In 2010, Congress passed a law to enhance pedestrian safety, instructing the agency to craft a rule mandating that hybrid and electric vehicles emit noise. Automakers requested a few changes, though, including allowing owners to choose from a range of sounds rather than just one. As a result, major carmakers have been working on crafting sounds to meet those requirements.

“It wants to be purposeful; it wants to be pleasing,” said Todd Bruder, the engineer who led development of the sound. “But also have the ability to warn people that there’s something coming.”

Meanwhile, safety experts are also concentrating on investigating dangers that future self-driving cars may face when confronted with a railroad crossing. Train-vehicle crashes are a lot more common than most people think. According to compiled statistics, every 90 minutes in the United States a vehicle and a train collide, and there are about 500 deaths each year in the United States due to failures to safely navigate a railroad crossing, according to Forbes.

Will AI-driven self-driving cars be safer than human drivers when it comes to dealing with railroad crossings? The answer is “maybe.”

True self-driving cars are those in which the AI does all the driving. Usually referred to as Level 4 and Level 5, there isn’t a human driver involved in the driving act. Level 2 and Level 3 cars are considered semi-autonomous cars, requiring a human driver to co-share the driving task. But the AI system of self-driving vehicles is not an all-knowing technology that can automatically cope with any driving scenario.

This co-sharing arrangement has some inherent problems, and drivers need to be wary of over-relying on advanced driver-assistance systems.

Potentially, a self-driving car that comes upon a railroad crossing could send out a message to other self-driving cars approaching the same spot and alert those AI systems that a train is coming. In theory, the trains themselves might also be able to do V2V, meaning that a rushing train would be broadcasting to nearby vehicles that the train is coming, so watch out. Any V2V-equipped car, truck, van or other kind of vehicle would get an electronic notification from the train itself.

There are other challenges to consider. Suppose the railroad crossing gate comes down to warn that a train is coming, but a train doesn’t come along and the gate arm stays down. This is dicey situation, since a human driver might be tempted to drive around the gate arm, first hopefully double-checking that there’s no train within eyesight. But most self-driving cars would simply sit stopped at the gate arm because it assumes that it can only proceed when the gate arm goes up.

Recent news stories about the automatic braking system of the Nissan Rogue have suggested that the brakes at times are being suddenly and inappropriately deployed at railroad crossings, endangering the passengers of the car and certainly startling or unnerving the human driver. Whether or not the allegation is ultimately shown to be true, it nonetheless highlights the potential dangers of car automation related to railroad crossings.

Eventually, the U.S. will have fully operational AI self-driving cars that have been prepared to handle such matters, though in the meantime it is prudent to be wary about any self-driving car that comes upon a railroad crossing. It’s a tough hurdle to match to the everyday human-devised mantra of stop, look and listen—even for AI.