Switching to Autonomous Mode is also something that designers work on. Whether you pull pedals or push a button, you are giving the control to the machine which I believe is not the main problem. Actually switching back to Manual Mode is something that must be design very carefully since the machine is giving the control back to the human and there can be problems during the transition. First of all, we need to make sure the transition is intentional. For safety concerns, we don't want our users to switch to manual by mistake. Second, there are three key factors in the transition: car seat, steering wheel and gas pedal.
The storyboard shows the task flow of switching to Manual Mode. Emma, 29, works in sales for a tech company in San Jose,California. She commutes to work everyday. She talks on phone with the customers even when she is driving. Also she has to make notes. Every morning she leaves her home around 7:45am and drive to work on highway 101. The traffic is terrible during the rush hour. So she switches to Autonomous Mode to save some time and do something productive instead.
The navigation system warns her that she needs to take an exit soon so she needs to switch back to Manual Mode. But the problem here is she might be focused on something else so she might not see a visual cue on the UI or hear an audio cue. In the story, she is reading a book so she is not looking at the visual screen. That's why the transition starts with her car seat buzzing. It's the signal that she needs to switch back to Manual Mode. Now she knows she needs to switch, she places her hands on the steering wheel. Touch sensors on the steering wheel are activated. Next step is the gas pedal. The car is going at a certain speed. So she needs place her feet on the gas pedal at a certain level to prevent a sudden speed change. Touch sensors on the pedal are activated. Finally the last step is to make sure she has a firm grip on the steering wheel, she finishes the transition by swiping up the button on the UI. Swiping up gesture makes her thumbs move upwards and her palms squeeze even harder.
It will be a new flow for the users who never drove a self-driving car in their lives so the user interface will play an important role in the process and walk the user through the steps. The lock screen in the Autonomous Mode informs the user that she can switch to Manual Mode by touching the steering wheel. The user needs to adjust the seat to touch the steering wheel. Once the seat is at the right position, it jumps the the next step and touch the steering wheel. Once the touch sensors on the steering wheels are activated, she puts her feet on the gas pedal and it lets the user know that all the steps are done. Two "swipe up" button on the sides appear for the confirmation.
This is another side project that I wanted to finish for the General Motors sponsored project. I thought switching to Manual Mode is going to be crucial human-machine interaction and it is more important than switching to Autonomous Mode because humans tend to do mistakes than the machines. I designed the flow and the screens but I could not show everything in the final presentation so I wanted to keep this here as a side project.