The assumption was for an ordinary driver, the expectation is that given sufficient lighting the vast majority of drivers would see and avoid a pedestrian. Most of the millions of pedestrian vehicle interactions daily go by without incident, one or the other party giving way, so this would be the normal expectation for an ordinary driver.

We can reasonably assume that pja is aware of the existence of abysmal drivers and fatal crashes that should not have happened. I doubt their intent was for "would" to be interpreted as "100%".