It's actually pretty interesting to see how the captchas have evolved as, presumably, Google decides "OK, we have enough data to consistently identify this thing" and moves on to the next challenge.
I recall the modern (non-text) captchas used to be cars pretty much every time. Then, the images started getting grainier as they apparently wanted to improve their recognition in different conditions. Then crosswalks and store fronts became quite common, eventually with the same kinds of noise distorting images. Now I've started seeing things like buses, bridges, motorcycles, bicycles, etc. It feels like they've finished getting enough data for improving Google Maps and have begun moving towards collecting data for their self-driving car projects.
I recall the modern (non-text) captchas used to be cars pretty much every time. Then, the images started getting grainier as they apparently wanted to improve their recognition in different conditions. Then crosswalks and store fronts became quite common, eventually with the same kinds of noise distorting images. Now I've started seeing things like buses, bridges, motorcycles, bicycles, etc. It feels like they've finished getting enough data for improving Google Maps and have begun moving towards collecting data for their self-driving car projects.