What is the most likely occurrence if an oncoming vehicle's right wheels drop off the pavement while you are driving at 45 mph?

When an oncoming vehicle's right wheels drop off the pavement, the driver may lose control of the vehicle temporarily. At a speed of 45 mph, the sudden change in traction when the wheels leave the paved surface can lead to a variety of reactions from the driver. The most likely outcome is that the vehicle will veer into your lane as the driver attempts to regain control and correct the vehicle's path. Drivers often unintentionally overcorrect by steering towards the center of the road when they first feel the drop-off, which can cause the vehicle to cross into an adjacent lane, posing a risk to any oncoming traffic.

The other possibilities involve various levels of control and awareness which may not necessarily manifest in this scenario. Continuing on the shoulder might seem plausible, but this often requires an intentional effort by the driver, who may be more concerned with regaining control than maintaining a steady exit onto the shoulder. Similarly, spinning out or smoothly returning to the road are less likely due to the factors of speed, momentum, and driver reaction under stress. Therefore, the most logical and concerning outcome is the potential for the vehicle to enter your lane, which places both drivers at risk.