Something that Jordan has mentioned was
minimize distracted driving while accommodating the users desire/urge to check their phones while driving.
Maybe you can also look into what the user deems important to them when it comes to their phones. I personally leave my phone on silent most of the time and have notifications turned off for most social media.But I am mostly distracted by my phone because I try to change songs while im driving. Maybe some people want to know exactly when they receive personal notifications or control certain information, but in a safer way. Maybe a priority contact list of calls or texts users are more likely to accept vs calling back later.
I’m a little confused on what you meant in contextual inquiry:
how social context influences on driving performance
What exactly do you mean by social context? Does that mean if there are kids in the car or if someone if driving with their friends? Maybe you need to focus on the type of driver? Single or had a family and children? I know kids that can also be a cause of distracted driving. These are all questions that I hope can help you focus on finding your audience to survey.