Google has lifted the bonnet on its efforts to develop driverless cars, a technology it's been working on for an astonishing eight years.
From virtual test worlds to the billions of miles its autonomous cars have travelled, here's what we learned about how far forward the tech giant's Waymo car project is.
1. Carcraft virtual world
Waymo has created its own virtual world for putting self-driving cars through their paces, according to an in-depth report published in The Atlantic.
Carcraft, as its named (after the game World of Warcraft), has virtual recreations of environments found in California, Phoenix and Texas, where in real life Waymo has the cars on the road. However, on a simulated road, many more situations can be thrown at them .
2. Roundabouts are complicated for computers
The spur for creating Carcraft was a real-life Texas roundabout. Apparently the complexity of the familiar road feature stumoed the vehicles, signalling that it might be a good idea to map these kind of situations out and 20,000 scenarios have so far been simulated and put to the test.
The true test of Waymo is surely going to be Swindon's seven-layered "magic roundabout".
3. Billions of miles
The sheer number of virtual cars Waymo has and the number of miles they have clocked up is really rather astonishing.
There are 25,000 virtual vehicles in Carcraft at any one time, driving eight million miles each day. Last year they clocked up 2.5bn miles of virtual driving. Compare that to the mere 2m miles its real life ones racked up by October last year.
4. A secret castle
Ok, so not actually a castle, but the Waymo real-life testing facility is apparently nicknamed Castle and is pretty hush hush and won't appear anywhere on Google Maps.
This fake city is where level 4 autonomy is being tested - level 5 being full autonomy and level 2 generally the level of most driverless cars being tested on public roads.