Tesla’s New 'Safety Score' Could Lead to Unsafe Driving, a CR Evaluation Shows

The automaker's gamification of safe driving could be an incentive, but Tesla should leverage its other capabilities to judge driver behavior

Tesla Model Y Photo: John Powers/Consumer Reports

Within hours of Tesla’s release of its new Safety Score feature, meant to qualify owners for access to the company’s latest version of its Full Self-Driving (FSD) software, some Tesla drivers were discussing on Twitter how they engaged in unsafe driving practices, such as coasting through stop signs or accelerating through yellow lights, to avoid lowering their score from braking too hard.

Kelly Funkhouser, head of automated and connected vehicle testing at Consumer Reports, says that the “gamification” of safe driving is a good idea to pursue but that Tesla’s approach could be having the reverse effect. When we tested the feature in September using our Model Y, we determined that the Safety Score threshold for unsafe hard braking could be exceeded by simply stopping at a stop sign in routine driving. And when we engaged Autopilot, the automaker’s driver assistance feature, and our Model Y approached that same stop sign and applied its brakes, it also exceeded the hard braking threshold. Tesla says that when Autopilot is engaged, the Safety Score is not affected.

Trying to avoid “hard braking” could lead drivers to coast through an intersection or fail to come to a complete stop for a pedestrian, Funkhouser says, adding that Tesla could make some changes to improve how it evaluates drivers in a way that encourages safer driving. “The problem is that Tesla appears to be using some of the wrong metrics,” she says. “Without more context, the data Tesla is collecting and scoring could create bad incentives.”

Tesla says it has internal data showing that the Safety Score improves driver performance. During an investor conference call Oct. 20, Zach Kirkhorn, Tesla’s chief financial officer, said that according to the automaker’s calculations, a driver using the Safety Score has a 30 percent lower probability of a crash than a driver who is not using it.

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Tesla announced in September that access to FSD 10.1—the latest version of software that can assist with parking, changing lanes on the highway, and coming to a complete halt at traffic lights and stop signs—would require owners to demonstrate “safe” driving for seven consecutive days.

The safety score takes into account five driving metrics that it gathers from a vehicle’s built-in sensors. In addition to hard braking, they include how often a driver turns aggressively, how many times forward collision warning is activated, whether a driver tailgates, and how often Autopilot—the automaker’s software that can control some steering, braking, and acceleration tasks—disengages because a driver has ignored warnings to keep their hands on the wheel.

Tesla has not said what it considers to be a high enough score to qualify. In theory, the score is supposed to make Tesla drivers safer behind the wheel. “These are combined to estimate the likelihood that your driving could result in a future collision,” the company says on its web page that describes the score.

It’s unclear whether drivers accepted into the program after seven days of safe driving can later lose access to FSD 10.1 because of a low safety score. Because drivers request access from their vehicle’s touch screen, Tesla says, the company can revoke access to the new FSD software for any reason.

Tesla did not respond to our questions about the safety score. But Tesla CEO Elon Musk said on Twitter that the score would be improved in the future. “Very much a beta calculation. It will evolve over time to more accurately predict crash probability,” he wrote.

To evaluate the effectiveness of Tesla’s hard braking metric, CR used an accelerometer to determine just how much force 0.3 g—Tesla’s Safety Score threshold for braking—represents in our Model Y. We found that common driving tasks, such as slowing from 25 mph to 0 mph while partially relying on the vehicle’s regenerative braking, would be enough to lower a driver’s Safety Score. CR’s experts note that 0.3 g isn’t a screeching halt with brakes squealing. It’s the kind of stop that most drivers would encounter on most drives.

It wasn’t until the accelerometer measured more than 0.5 g that our test drivers noted that a stop felt like a moderately hard braking event. Those stops were still nowhere near a seat-belt-locking emergency stop, which in our view would be an unsafe threshold.

Gaming the System

At its core, the Safety Score represents two ideas that could bring about positive safety benefits, says Jake Fisher, senior director of CR’s Auto Test Center. It monitors whether drivers are behaving safely on public roads, and it adds gamelike rewards to a relatively boring act like driving to give a motivation to make good choices behind the wheel—a concept known as “gamification.”

Research has shown that gamification can motivate individuals to adopt good habits. For example, a person who wants to get more exercise might respond well to a smartwatch that gives them a “badge” for walking a certain number of steps per day. Automakers often put a real-time fuel-economy monitor on the dashboard to encourage drivers to lay off the gas and conserve fuel. And a German study shows that gamifying safe driving can reduce driver distraction.

But gamification also has a dark side. Researchers at Ohio State University found that when teachers added gamification to the classroom, students were more likely to cheat to win rewards. And it appears that Tesla’s new safe driving metric may be encouraging drivers to find alternative ways of getting a high score, Fisher says.

“Drivers want access to the so-called Full Self-Driving software that they’ve already paid up to $10,000 for, so they may be willing to game the system to get a score that’s good enough,” he says.

@consumerreports Here's what 0.3 g's in Tesla's driver Safety Score looks like. Learn more at CR.org/TeslaSafetyScore #cartok #cartiktok #teslatok #cars ♬ original sound - Consumer Reports

Editor’s Note: This article, originally published Sept. 27, has been updated to clarify that when Autopilot is engaged, Tesla’s new Safety Score calculations are not affected. It has also been updated to add information shared in Tesla’s Oct. 20 earnings call.


Head shot photo of CRO Cars CIA editor Keith Barry

Keith Barry

Despite my love for quirky, old European sedans like the Renault Medallion, it's my passion to help others find a safe, reliable car that still puts a smile on their face—even if they're stuck in traffic. When I'm not behind the wheel or the keyboard, you can find me exploring a new city on foot or planning my next trip.