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Alcohol-impaired-driving laws are extremely complex. They may be difficult to understand, enforce, prosecute, and adjudicate, with many loopholes and inconsistencies. In many States, a thorough review and revision would produce a system of laws that would be far simpler and more understandable, efficient, and effective.

DWI laws have evolved over the years to incorporate new definitions of the offense of driving while impaired (illegal per se laws), new technology and methods for determining impairment (e.g., BAC tests, Standardized Field Sobriety Tests [SFSTs]), and new sentencing and monitoring alternatives (e.g., electronic monitoring, alcohol ignition interlocks). Many States modified their laws to incorporate these ideas without reviewing their effect on the overall DWI system. The result is often an inconsistent patchwork. Robertson and Simpson (2002) summarized the opinions of hundreds of law enforcement officers, prosecutors, judges, and probation officials across the country: “Professionals unanimously support the simplification and streamlining of existing DWI statutes” (p. 18). Before it disbanded, the NCUTLO (2000) prepared a model DWI law, which has been incorporated into the Uniform Vehicle Code. It addressed BAC testing, BAC test refusals, higher penalties for high-BAC drivers, ALR hearing procedures, and many other issues. States can use the NCUTLO model as a reference in reviewing their own laws. In addition, the TIRF has a guidebook (Robertson et al., 2007) to assist policymakers in leading a strategic review of DWI systems, with the goal of streamlining systems and closing loopholes. NHTSA also has created several guidebooks, including one to assist States in establishing impaired-driving statewide task forces to review key legislation and improve current DWI systems (Fell & Langston, 2009), and another to assist officials and the general public in establishing task forces at local or regional levels (Fell, Fisher, & McKnight, 2011).

At a State’s request NHTSA will facilitate an Impaired-Driving Program Assessment to evaluate the State’s impaired-driving system and to make recommendations for strengthening its programs, policies, and practices. NHTSA and the State’s Highway Safety Office assemble an assessment team comprised of national and State experts in impaired driving. The team interviews representatives from agencies across the State, and reviews local data to document the strengths and weaknesses of the State’s impaired-driving system. The team provides the State with written recommendations on actions to improve the impaired-driving system.


It is unknown how many States have conducted reviews of their overall impaired-driving system. Several States work with NHTSA each year in conducting assessments.


To date there is no information on the impact of law reviews in reducing alcohol-impaired crashes. The effect of a law review will depend on the extent of inconsistencies and inefficiencies in a State’s current laws. A law review can be an important action a State takes to address its alcohol-impaired-driving problem, because a thorough law review will examine the function of the entire DWI control system and will identify problem areas. The effect of a law review should be a more efficient and effective DWI control system.

Some States that have incorporated assessments into their programs have experienced declines in impaired-driving fatality rates. Coleman and Mizenko (2018) reported case studies of three States—New Mexico, Oklahoma, and Washington—that implemented an impaired-driving leadership model. Key elements of the leadership model included conducting an impaired-driving assessment, developing an impaired-driving strategic plan, assembling a leadership team, providing authority to the team, and garnering support of the State’s governor. After implementing the leadership model, all 3 States showed reductions in impaired-driving fatality rates per 100 million VMT. Although encouraging, these reductions may also reflect factors or trends in each State beyond just the leadership model. See Coleman and Mizenko (2018) for more information about the leadership model, including lessons learned and recommendations for other States.


The review will require substantial staff time. Implementation costs will depend on the extent to which the laws are changed.

Time to implement:

It can take considerable time to identify qualified stakeholders and establish a task force to conduct the law review.