Examining Driver Vigilance in Partially Automated Vehicles: The Impact of Push Notifications

Partially automated vehicles shift drivers’ roles from full control to monitoring automation and intervening when needed. This task requires vigilance—the ability to stay alert and respond to important events over time. However, vigilance tends to decline over time, a phenomenon known as vigilance decrement. In-vehicle systems like Android Auto and Apple CarPlay may further reduce vigilance by delivering push notifications that capture visual attention and momentarily divert focus from the road. According to multiple resource theory, when two tasks compete for the same cognitive resources, performance can decline. This study examined how push notifications affect vigilance during partially automated driving. Participants completed a 40-min simulated drive either focusing solely on driving and identifying road hazards or driving while also responding to notifications. Results showed that participants detected fewer hazards and were less sensitive when handling notifications. These findings suggest that push notifications can compromise driver vigilance and raise safety concerns.