The moment a Waymo picked me up in the rain

Heavy rain in San Francisco. The kind where gutters overflow and the streets turn into shallow rivers and everyone drives 15 under the speed limit with their hazards on, which somehow makes everything more dangerous.

I opened the Waymo app and requested a ride. Part of me expected it to be unavailable. Rain messes with LIDAR. Raindrops create false returns. Water on the road changes surface reflectivity. Puddles confuse cameras.

The car showed up in four minutes.

What I saw

Windshield wipers going. Headlights on. It pulled to the curb precisely, avoiding the stream of water running along the gutter. The door unlocked. I got in.

The car pulled away smoothly. At a flooded intersection, it slowed significantly, assessed the water depth (I assume via a combination of LIDAR and mapping data), and drove through at about 5 mph. A human driver behind us honked. The Waymo didn’t care.

On the highway approach, the car maintained a larger following distance than it does in dry weather. The lane-keeping was confident but the speed was conservative. When spray from a truck temporarily reduced visibility, the car slowed another 5 mph without any jerk or sudden braking. Just a smooth deceleration.

It was calmer than me. Calmer than most human drivers I’ve ridden with in rain.

The trust moment

I noticed it about halfway through the ride. My body was relaxed. My hands weren’t gripping the door handle. I wasn’t watching the road with that anxious vigilance that rain usually triggers.

I trusted the car more in the rain than I trust most human drivers in the rain.

That’s backwards from what I expected. Rain should be harder for a robot. The sensors are degraded. The conditions are unpredictable. This should be where human intuition wins.

But human intuition in rain is actually pretty bad. We drive too fast. We follow too closely. We hydroplane because we don’t slow down enough. We panic brake. The Waymo did none of these things.

The car drove the way you wish every human would drive in rain. Patient. Conservative. Smooth. Unbothered.

What this changes

Rain was supposed to be the hard problem for self-driving. “Sure, it works on a sunny Phoenix afternoon. But rain? Snow? Fog?” These were the gotcha questions.

The Waymo drove me 11 miles through heavy rain in San Francisco without a single moment of hesitation. The gotcha got answered.

There are still hard weather problems. Heavy snow with no lane markings. Ice. Dense fog. Those are genuinely difficult and I don’t think anyone’s solved them yet. But rain, which is the most common challenging weather condition, appears to be handled.

I got out of the car dry and relaxed. The rain was still coming down hard. Another Waymo pulled up to the spot I’d vacated, picking up the next passenger.

Routine. In the rain. At night. In San Francisco.

I keep waiting for the moment when self-driving stops surprising me. Maybe this was it.

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