All states have laws that prohibit drivers from making unsafe lane changes. State laws generally require a driver on a road with marked lanes to operate the vehicle within a single lane and to move to another lane only at a time and in a manner that is safe.

This means a driver may not cross more than one lane of traffic at a time, must allow a safe distance between the driver’s vehicle and other vehicles, and must signal the lane change with a blinker, as required by law. The failure to do so may result in a ticket or citation for an unsafe lane change.

The penalty for making an unsafe lane change usually includes a fine and demerit points on your driver’s license or record.

As with many traffic violations, the officer issuing the citation and the prosecutor have significant discretion in determining whether there was a violation of a traffic law and whether the violation constitutes a certain offense, as defined by the state legislature in the traffic code or in a municipal ordinance.

This discretion to issue a ticket or citation and prosecute the charge against the driver is balanced by the discretion of the jury or judge in determining whether the prosecution met its burden of proof sufficient to convict the driver (for a criminal offense) or find the driver responsible (for a civil infraction, violation, or offense).

In South Carolina, as in all states, laws are in place to ensure that drivers make lane changes safely. South Carolina Code of Laws Section 56-5-1880 mandates that drivers must stay within a single lane on roads with clearly marked lanes and may only move to another lane when it can be done safely. Drivers are required to signal their intention to change lanes using their vehicle's turn signals. Making an unsafe lane change, such as crossing multiple lanes at once or failing to maintain a safe distance from other vehicles, can result in a traffic citation, which typically carries a fine and may add demerit points to the driver's license record. The discretion to issue a citation and pursue prosecution lies with law enforcement officers and prosecutors, while the determination of guilt or responsibility is made by a judge or jury, depending on whether the offense is considered criminal or a civil infraction.