Which scenario requires immediate action by law enforcement regarding a traffic violation?

The scenario involving a refusal to sign a citation requires immediate action by law enforcement because it indicates non-compliance with the legal process associated with a traffic stop. When a driver receives a citation, signing it is typically an acknowledgment of receiving the citation and a promise to appear in court or pay the fine. Refusal to sign can complicate the enforcement process and may be viewed as an act of defiance or non-cooperation. This situation may necessitate additional measures, such as determining whether to arrest the individual or to take further steps to ensure compliance with the law.

In contrast, minor lane changes, failure to signal, and slightly exceeding the speed limit generally indicate less severe violations that can usually be addressed through warnings or citations rather than immediate enforcement measures. These infractions do not inherently obstruct the law enforcement process or suggest that a driver is unwilling to cooperate, which is why they do not require the same level of immediate action as a refusal to sign a citation.