Final answer:
A driver could face up to 90 days in jail for a second DUI conviction, but actual sentences can vary based on jurisdiction, specific circumstances, blood alcohol content, and state laws.
Step-by-step explanation:
Upon his or her second DUI conviction, a driver could spend up to 90 days in jail. However, it's important to note that DUI laws can vary significantly from one jurisdiction to another. In some places, mandatory minimum sentences might be imposed, while in others, judges may have some discretion in sentencing. Factors such as the presence of aggravating circumstances, the driver's blood alcohol content at the time of arrest, and state laws can all influence the length of jail time. Drivers might also face fines, community service, probation, and mandatory alcohol education programs or rehabilitation.