First, many chronic drinking drivers are alcoholic, which impairs their judgment and decision making skills. Secondly, in states where suspension is imposed as a penalty only after a criminal trial and conviction, the time between the arrest and license revocation is often long, and in some cases diversion programs allow the offenders to retain their licenses during the lengthy delay, both of which are associated with higher recidivism rates. Research has shown that to maximize the deterrent effects of a law the punishment must be perceived as certain, swift, and appropriately severe. A study in New York determined that drivers arrested for drunk driving who were able to delay their criminal trials or avoid conviction had recidivism rates which were three times higher than those offenders processed in a timely manner and who were convicted of a DUI or lesser traffic offense. A recent study in Ohio supports the effectiveness of administrative suspensions in general, and also found decreased DUI recidivism among repeat offenders, even two years after suspension, especially when coupled with procedures to immobilize offenders' vehicles.
Experts recommend eliminating diversionary programs that allow offenders to keep their licenses.
Furthermore, BAC limits for drivers following a DUI conviction could be set lower than the limit which applies to drivers in general. Research in Maine on the effects of a .04 BAC limit for repeat DUI offenders indicated this lower limit was associated a substantial decrease in fatal alcohol-involved crashes in this group of DUI offenders. Persons caught driving while their licenses are suspended can be separated from their vehicles. This could be accomplished through the impoundment or immobilization of the vehicle, or the license plates could be seized. This can occur administratively at the time of arrest.