PYEONGCHANG, South Korea -- I've replayed the episode countless times in my head.
Was this computer-controlled car going to stop on its own, or barrel through a busy crosswalk?
I'm still not sure.
An autonomous prototype of Hyundai's fuel cell powered Nexo crossover was quickly approaching a bustling pedestrian crossing near an entrance to the Winter Olympics here on Feb. 21. Hyundai was demonstrating its Level 4 autonomous vehicle technology, which it plans to commercialize in certain cities by 2021.
I was in the back seat, anticipating how the robotic Nexo would react. The system had been driving conservatively up to that point of the brief demo, so I figured the Nexo would recognize the pedestrians who were being picked up by its sensors and decelerate to a gradual stop.
But that's not what happened.
The Nexo continued forward at deliberate pace while yellow lights flickered above the crosswalk. It showed no signs of stopping.
Then, with the crosswalk just 10 or so feet ahead of us, the engineer in the driver's seat hit the brakes himself to avert potential calamity.
A Hyundai rep in the back seat with me said it would have stopped itself. He may be right.
But the best-case scenario in this instance would've seen the Nexo terrifying pedestrians by coming shockingly close to them before braking. It didn't have much more room to work with. And the worst case would have been international news.
The crosswalk incident showed the unpredictability that automakers face in the deployment of autonomous systems, which must be tested in real-world conditions to prove themselves, with all the risks that come with that. One ride can be perfect and elicit optimism. The next ride will show there's still work to be done.
While other reporters had uneventful demos on the same path that showed autonomous driving in all of its glory, my ride provided a shock, and a jarring dose of reality.
But it wasn't a heart-pounder throughout. In fact, the demo was a marvel for much of the ride, and felt eerily normal at times.
The crosswalk was an obvious outlier. But overall, the system displayed a patient, by-the-book driving style.
The tech also dazzled. In the most impressive feat, the Nexo approached a roundabout and read the traffic with no problem. The system waited for the proper clearing as vehicles passed, then made its way around the bend.
Hyundai is charging toward a goal of full autonomy by 2030. Earlier this month, a fleet of Nexos packed with Level 4 autonomous tech traveled 118 miles from Seoul to Pyeongchang. The automaker said the vehicles moved with the "natural flow of traffic" on the highway. The vehicles completed lane changes and "overtaking maneuvers" to complete the journey. External sensors could pinpoint the positions of the vehicles on maps when the GPS signal was interrupted.
Progress is definitely being made. But the experimentation continues.
"We're still working on it. That's why you have someone there," a Hyundai spokesman said later after learning of the crosswalk close call. "This was an early experience for journalists to see how everything works."