Why might a driver wait until the next scheduled stop to discharge a disruptive rider rather than pulling over right away?

49 CFR 383.117(a)(3), proper responses to emergency situations such as fires and unruly passengers; AAMVA CDL Manual Section 4.3.2 (p.4-3)

Discharging a disruptive or intoxicated rider in an unsafe, poorly lit, or isolated spot can turn a behavior problem into a safety emergency. The manual's guidance to prioritize a safer location is central to the federal "emergency response to unruly passengers" test topic.