The way ahead is fairly clear. First, self-driving sidewalk delivery robots: 4 mph. 50 lb: low-stakes. Then bike lane delivery robots: 12 mph, 100 lb: medium

The way ahead is fairly clear. First, self-driving sidewalk delivery robots: 4 mph. 50 lb: low-stakes. Then bike lane delivery robots: 12 mph, 100 lb: medium stakes. Then geofenced road vehicles: controlled stakes. We're about at the comma after "First" above.