What empirical evidence supports the notion that cycling is inherently more beneficial for mental health than driving, considering factors such as cortisol levels, adrenaline release, and cognitive functioning? Is it not possible that the perceived benefits of cycling are largely due to the added physical activity, rather than the mode of transportation itself? Furthermore, have studies adequately controlled for variables such as traffic stress, weather conditions, and social interaction while driving, which could potentially offset any mental health benefits of cycling?