There are more ways to get around in urban metro areas than ever before. We have on-demand cabs like Uber and Lyft. Shareable bikes and scooters became so pervasive they were piling up in lakes . This new wave of transportation technology was supposed to make the world easier to navigate and most of all safer. That may still be the case—in the end. But in the murky middle, as futuristic cars, e-bikes, and scooters make their first entries onto roads, travel might become momentarily more perilous, not less.

The future of transportation is starting to look like a public health hazard. A study from the University of California and Stanford University surveyed two hospital emergency departments in California over a one-year period and found that 249 injuries were related to scooters. Uber is constantly having to develop new tools to show its commitment to safety because of issues with sexual assault and fake Ubers, where people fraudulently pose as Uber drivers to harm others. Self-driving cars have also seen their image crash in the last year, thanks to heavily publicized accidents and one fatality. Expectations for their ultimate arrival have been put off indefinitely.

But even certain features you might get in a standard new car are proving unreliable. A new study released by AAA says that pedestrian-avoidance technology—one of several new automated tools including emergency braking, lane-keeping, adaptive cruise control, limited autonomous driving, and collision warning—isn’t working when it’s needed most, according to the Wall Street Journal. It tends to sputter when it’s dark out.

Typically, that’s fine, because there’s a driver behind the wheel—or so the logic goes. But assistance features introduce a new problem, which is that drivers become overly reliant on them and tune out while driving.

No company has felt this pain as acutely as Tesla, which has cars with self-driving-lite technology called Autopilot. The company’s cars have been involved in several publicized crashes. CEO Elon Musk has said that all the incidents were the fault of an inattentive driver. That might be true, but it doesn’t reflect the complexity of the situation. In 2018, a Tesla crashed into a fire truck parked on the highway. The vehicle alerted the driver of the crash less than a second before impact and failed to engage emergency braking. Is 0.49 seconds enough time for a person to respond to a collision they didn’t see coming? Also, what happened to those emergency brakes?

There was once a belief that cars that drive themselves would be our caped saviors. In 2015, there was reason to believe that by 2050, self-driving cars would reduce death by car accident by 90%—and conceivably save tens of thousands of lives every year. Some researchers were so certain of the ultimate good of self-driving machines that one of the few safety concerns was around the Trolley Problem, whether an autonomous car in a collision would chose to save the most people possible or its own passengers.