What is the only Title 39 violation that can be stopped for while off duty?

The only Title 39 violation that can be stopped for while off duty is DUI 39:4-50. This violation pertains to driving under the influence, which presents a significant risk to public safety regardless of whether an officer is on duty or off duty. Law enforcement officers have a duty to uphold the law and protect the community at all times, and driving under the influence poses a direct threat not only to the driver but also to others on the road.

The other options, while still unsafe and potentially illegal, do not typically warrant intervention by an officer who is not on duty. For instance, reckless driving can be serious but is often subject to the discretion of the officer's presence and ability to intervene. Similarly, speeding and failure to wear a seatbelt are typically addressed through traffic enforcement measures that do not require an officer to act while they are off duty. Thus, DUI 39:4-50 stands out as the violation that demands immediate action due to the severe implications it has for safety, allowing officers to stop individuals committing this offense even outside their official duties.