For new drivers, and a few experienced ones as well, a three-point turn can sometimes turn into a five-, seven-, or even nine-point calamity, the messed-up maneuver accompanied by a selection of randomly uttered swear words emitted in frustration at your apparent inability to get the car to do what you want it to do.
Turning around in a tight spot is a maneuver that engineers working on Google's driverless car technology have long known they have to perfect, and according to the latest news out of Mountain View, it sounds like they've already nailed it.
Discussing the subject of multi-point turns in its latest monthly report on its driverless car project, Google notes that while "human drivers do their best to estimate the ideal angle and distance to move in order to solve this geometric puzzle," all too often they're left moving back and forth like a pendulum, the car's passengers wondering if the awkward experience will ever end.
But thanks to its myriad of sensors and clever computing power, Google's specially developed car is able to gain a full view of its surroundings and measure distances down to a few centimeters, allowing it to quickly work out the most efficient way to complete a full turn while its occupants sit back and relax.
"Our cars don't just follow a few standard turns either," Google said. "We've taught them to adapt to all kinds of variables -- including dead-end streets stacked with parked cars, trash bins littered on the curbs, and narrow bottlenecks."
To hone the turning technology, Google's cars have been practicing the maneuver around 1,000 times a week on regular city streets.
The company said it's also working to ensure that the maneuver mimics the way humans would do it, in other words, choosing recognizable turns rather than any obscure ones that might feel unnatural to those riding in the car.
Google explains: "There are an infinite number of possible ways to turn a car around. Both human drivers and self-driving cars have to calculate tradeoffs -- how wide do we move? How close do we get to the curb? How many times do we change direction?"
It says its challenge is to "teach our self-driving cars to choose the option that's not only the quickest, but one that feels natural to passengers. For example, our cars could spend most of the three-point turn driving in reverse (after all, our sensors don't have to twist into a yoga pose to get a full 360 degree view of the road behind). But that's not how people drive -- they'd much rather drive forward where they have better visibility of the road and can more easily maneuver the car. So we've taught our cars to mimic these human patterns, favoring wider forward arcs, rather than a series of short movements back and forth."
Google's report noted that its fleet of self-driving cars currently includes 34 of its pod-like vehicles and 24 modified Lexus RX450h SUVs driving autonomously on public roads in California, Arizona, Texas, and Washington.