Iowa has many requirements for someone convicted of a DUI. These requirements are handed down by both the criminal court, and the Iowa Department of Transportation.
The IDOT will require any driver that failed a breath test or refused a breath test (whether 1st or any subsequent failure) to take an approved drinking drivers’ course prior to becoming eligible to obtain their license again.
The IDOT does not care if a 12-hour course is taken, or the 48-hour course is taken. Either way, this will satisfy their requirement.
So, apples-to-apples, the 12-hour course should be the obvious choice.
Then why does the 48-hour course exist?
The 48-hour course can be approved by the criminal court to satisfy the State’s requirement for a minimum of 48 hours in jail. This can be required (and in Johnson County is nearly always is) even when a deferred judgment is granted.
Therefore, it is wise to take the 48-hour course only when the criminal court requires or authorizes it. This will allow the driver/defendant to “kill two birds with one stone.”