Traffic Safety: Alcohol Ignition Interlocks Are Effective While Installed; Less Is Known about How to Increase Installation Rates
Published: 2014-06-20T00:00:00

Fast Facts:

Highlights:
section_title: Why GAO Did This Study
paragraphs: Motor vehicle crashes involving alcohol-impaired drivers killed 10,322 people in 2012 and account for almost one third of all traffic fatalities annually. Ignition interlocks are one strategy states use to combat DWI. In 2012, MAP-21 established a grant program for states that adopt and implement mandatory alcohol ignition-interlock laws for all convicted DWI offenders. Funding authorization for this program expires at the end of fiscal year 2014.
GAO was asked to review the effectiveness of ignition interlocks and NHTSA's implementation of the new grant program. This report discusses (1) what is known about ignition interlock effectiveness and (2) the extent to which NHTSA has assisted states in implementing ignition-interlock programs, including the grant program. GAO reviewed 25 studies that analyzed relationships between ignition interlocks and DWI arrests and fatalities; interviewed NHTSA officials and reviewed reports about NHTSA's assistance to states; and interviewed representatives from safety-advocacy and research organizations, and officials involved with ignition-interlock programs from 10 states. The states were selected based on grant program qualification and the number of alcohol-impaired fatalities, among other factors. The information from these states is not generalizable. DOT officials reviewed a draft of this report and generally agreed with the findings. DOT offered technical corrections, which we incorporated as appropriate.
section_title: What GAO Found
paragraphs: Research GAO reviewed consistently indicated that when installed ignition “interlocks”—devices that prevent drivers from starting their cars if they have been drinking alcohol—effectively reduce the rate of re-arrest for driving while intoxicated (DWI) when installed. But once the devices are removed, DWI re-arrest rates return to pre-interlock rates. (Most studies use DWI arrest as a proxy for alcohol-impaired driving.) Further, the National Highway Traffic Safety Administration (NHTSA) estimated that between 15 and 20 percent of offenders arrested for DWI actually install ignition interlocks. Many factors contribute to low installation rates. For example, some states lack the resources to monitor offenders to ensure they install ignition interlocks; other states require that offenders pay fees and penalties to be eligible to install ignition interlocks and return to driving with interlocks. State ignition interlock programs vary in terms of how they are designed, but little research exists on which specific interlock program characteristics—such as monitoring or length of installation—could improve the effectiveness of interlock programs. NHTSA is currently conducting studies on factors that could help states improve installation rates or otherwise improve the effectiveness of their interlock programs. NHTSA expects these studies to be completed by 2015.
NHTSA has offered a variety of technical assistance, research, and education to help states establish and improve their ignition-interlock programs, as well as implement the ignition interlock grant program established by the Moving Ahead for Progress in the 21st Century Act (MAP-21). While state officials confirmed that NHTSA's overall ignition-interlock-related activities have been useful, some questioned NHTSA's implementation of the ignition interlock grant program. Specifically, NHTSA's implementation was based on the plain meaning of the authorizing language in MAP-21, which did not include any reference to exemptions. As a result, states with “employer exemptions”—programs that require offenders to drive only vehicles equipped with ignition interlocks for personal use but allow them to drive employer-owned vehicles for work purposes—were disqualified. Some state officials told us these exemptions are seldom used in practice, but are important to maintain because they facilitate the ability of offenders to work. According to NHTSA officials, they recognized that to qualify for the grant, many states would have to modify their ignition-interlock laws to make them applicable to first time offenders and eliminate exemptions; therefore, few states were expected to qualify in the grant's first years because it would be difficult for state legislatures to change their ignition-interlock laws in that time frame. In fiscal year 2013, 2 states qualified for the grant; most of the additional 12 states that applied for the grant were disqualified at least in part due to employer exemptions, but the legislatures in 2 of those states later removed such exemptions from their laws, resulting in 4 states qualifying for the grant in fiscal year 2014. Because the ignition interlock grant is relatively new, the extent to which additional state legislatures may be willing or able to modify their laws to qualify for the grant is unclear. A 2012 NHTSA review of states' impaired-driving laws found that at least 5 states' ignition-interlock laws included employer vehicle exemptions, but additional states had other factors that would prevent them from qualifying for the ignition-interlock grant.

section_title: Letter
paragraphs: In 2012, motor vehicle crashes involving alcohol-impaired drivers killed  10,322 people. While the number of such fatalities has dropped by 21  percent over the last 10 years, almost one third of all traffic fatalities  annually resulted from crashes involving an alcohol-impaired driver over  the same period. Breath alcohol “ignition interlocks” are devices that  prevent a driver from starting a car if the device detects a driver’s blood  alcohol concentration (BAC) above a certain threshold. Ignition interlocks  represent one of the strategies states use to combat alcohol-impaired  driving. California first piloted the use of ignition interlocks in 1986 for  drivers convicted of driving while intoxicated (DWI). According to the  National Highway Traffic Safety Administration (NHTSA), all states have  enacted legislation requiring or permitting the use of ignition interlocks.  Historically, Congress has provided funds for state programs to reduce  alcohol-impaired driving. Most recently, the 2012 surface transportation  reauthorization act—Moving Ahead for Progress in the 21st Century Act  (MAP-21)—also included funding for a new grant program for states with  laws mandating that all drivers convicted of DWI be allowed to drive only  vehicles equipped with an ignition interlock. NHTSA assists states in  implementing these programs and, in addition to other safety  organizations, has funded research examining the effectiveness of  ignition-interlock programs.
In light of the toll alcohol-impaired driving takes, you asked us to review  the effectiveness of ignition interlocks and NHTSA’s implementation of  the MAP-21 ignition-interlock program. This report discusses (1) what is  known about the effectiveness of ignition interlocks in reducing alcohol- impaired driving and (2) the extent to which NHTSA has assisted states in  implementing ignition-interlock programs, including the MAP-21 ignition- interlock grant program.
To identify what is known about the effectiveness of ignition interlocks, we  reviewed 25 studies conducted between 1990 and 2013 that analyzed  relationships between ignition interlock devices or programs and alcohol- impaired driving outcomes, including DWI arrests and DWI fatalities. We  identified these studies from a literature search and recommendations  from organizations that conduct research on ignition interlocks, such as  the Pacific Institute for Research and Evaluation. To identify the types of  assistance that NHTSA provides to states to help them establish and  implement their ignition-interlock programs, we interviewed NHTSA  officials about their activities and reviewed reports describing NHTSA’s  ignition-interlock-related research, technical assistance, and conferences.  For both objectives, we interviewed representatives from safety advocacy  organizations such as the Governors Highway Safety Association (GHSA)  and Mothers Against Drunk Driving (MADD). We also interviewed traffic  safety, criminal justice, department of motor vehicles or licensing, and law  enforcement officials from 10 states. The states were selected based on  MAP-21 ignition-interlock grant program qualification, DWI fatality  numbers in 2012 (most recent data available), and alcohol-impaired  fatalities per 100-million vehicle-miles traveled as calculated by NHTSA.  (See app. I for more information on scope and methodology and app. II  for a list of reviewed studies.)
We conducted this performance audit from July 2013 to June 2014 in  accordance with generally accepted government auditing standards,  Those standards require that we plan and perform the audit to obtain  sufficient, appropriate evidence to provide a reasonable basis for our  findings and conclusions based on our audit objectives. We believe that  the evidence obtained provides a reasonable basis for our findings and  conclusions based on our audit objectives.
subsections: section_title: Background
paragraphs: While alcohol-impaired driving fatalities have declined from over 21,113 in  1982 to 10,322 in 2012, the proportion of such fatalities as a percent of  total traffic-related fatalities has remained relatively constant—between  30 and 32 percent—over the past 15 years. Congress has targeted this  persistent problem through legislation to encourage states to reduce their  illegal per se BAC limit. For example, beginning in 1982, federal  legislation authorized grants to states to establish an illegal per se BAC  limit of 0.10 or greater while driving a motor vehicle. In other words, with  respect to a BAC limit of 0.10, anyone whose blood contains 1/10th of 1  percent of alcohol or higher would be deemed to be DWI. In the late  1990s, Congress made grant funds available to states to encourage them  to further lower the illegal per se driving BAC limit to 0.08. In 2000, the  U.S. Department of Transportation Appropriations Act for fiscal year 2001  included a provision that states must enact 0.08 BAC laws by fiscal year  2004 or begin losing federal highway construction funds. According to  NHTSA, all states had complied with that provision by 2004.
NHTSA administers safety-incentive grant programs to assist states in  their efforts to reduce traffic-related fatalities, including alcohol-impaired  fatalities.  NHTSA also provides guidance and technical assistance, sets  and enforces safety performance standards for motor vehicles and motor  vehicle equipment, and conducts research on driver behavior and traffic  safety. As part of such research, NHTSA works with traffic safety  organizations, such as GHSA, MADD, and the Traffic Injury Research  Foundation (TIRF).
In fiscal year 2014, NHTSA requested a total budget of $828 million and 653 full time  equivalent employees . NHTSA personnel are located in Washington, D.C. and among 10  regional offices. “The Secretary  shall make a separate grant under this subsection  to each State that adopts and is enforcing a mandatory alcohol-ignition interlock law  for all individuals convicted of driving under the influence of alcohol or of driving while  intoxicated.”
See Section 31105(a) of MAP-21, Pub. L. No. 112-141, 126 Stat. 405, 748 (2012). surface transportation programs—including the ignition-interlock grant  program—for fiscal year 2015 and beyond.
The first ignition interlock was developed in 1969, but early models relied  on alcohol sensors that were inconsistent in accurately identifying BAC. In  the early 1990s, ignition interlock manufacturers began producing more  reliable and accurate fuel cell sensors, which is a technology currently in  use.ignition interlocks that describe how ignition interlocks should perform and  how the device can be calibrated to meet the model specifications.  NHTSA updated these specifications in 2013.
In 1992, NHTSA published model technical specifications for  Ignition interlocks currently in use have four basic elements:  1.  A breath alcohol sensor in the vehicle that records the driver’s BAC  and sends the signal to not start the engine if the BAC registers higher  than the predetermined limit (see fig. 1);  2.  A retest system; 3.  A tamper-proof system for mounting the part of the unit that prevents  the engine from starting, which is typically required to be inspected  every 30 to 60 days to prevent circumvention; and  4.  A data-recording system that logs the BAC results (for the initial test  and retests) each time the vehicle is turned on and off, the time period  the vehicle was driven and mileage, and other data that may be used  by state authorities to monitor the offender’s behavior.
The ignition interlock requires the driver to submit breath samples at random times to  ensure that the driver does not drink alcohol after the engine has been started. The driver  is given several minutes to exit traffic and move to a safe location to take the test. If the  breathe sample is not provided or the sample exceeds the set point, the device may warn  the driver and activate an alarm (e.g., horn blowing, lights flashing) that will continue until  the ignition is turned off or a breath sample that is within the acceptable limits is provided.  For safety reasons, the interlock device cannot turn off the vehicle’s ignition once it has  been started.
section_title: Research Indicates Interlock Devices Are Effective While Installed, but Installation Rates Are Low and Research on Strategies to Increase Rates Is Limited
paragraphs: Research we reviewed consistently indicated that ignition interlocks  reduce the rate of re-arrest for DWI while they are installed on the vehicle,  but once removed, DWI re-arrest rates return to pre-interlock rates. In  addition, the percentage of DWI offenders who actually install an interlock  when ordered is estimated to be low. Several factors contribute to this low  rate, including low enforcement and monitoring to ensure offender  compliance and costly fees and penalties that DWI offenders have to pay  before they are eligible for interlock-restricted driving privileges. Little  research exists on which specific interlock program characteristics may  improve installation rates or otherwise improve the effectiveness of  ignition-interlock programs, but NHTSA’s ongoing and planned  research—expected to be completed between 2014 and 2015—may fill  this gap.
subsections: section_title: Ignition-Interlock Devices Reduce Re-arrest While Installed
paragraphs: Research consistently indicated that ignition interlocks are effective while  installed. That is, installation of ignition interlock devices in DWI offenders’  vehicles reduces re-arrests for DWI when compared to alternative  sanctions such as license suspension. Most studies use DWI arrest as a  proxy for alcohol-impaired driving; however researchers have noted that  arrest for DWI is a rare event, with some estimating that less than 1   A 2011 review of  percent of alcohol-impaired drivers are detected.literature assessing the effectiveness of ignition interlocks identified 15  studies (12 in the U.S., 2 in Canada, and 1 on Sweden) that observed  that ignition interlock installation reduced the risk of being re-arrested for  DWI offenders, compared to DWI offenders not using ignition interlocks.  The studies included in this review primarily evaluated programs directed  at drivers with multiple DWI offenses or first-time offenders with high BAC  at arrest (usually >0.15). As noted by the authors, the majority of studies  in this review and those that we separately identified did not randomly  assign participants to the ignition interlock; therefore, a limitation of many  of these studies remains the potential for selection bias, as individuals  who agree to install an interlock may be inherently different from  individuals who do not agree to do so. However, we did identify two  randomized controlled trials, both in Maryland and limited to offenders  with two or more alcohol-related traffic violations, that also found that  ignition interlocks are effective at reducing re-arrests. The first, published  in 1999, found that being in the interlock program—including installing an  ignition interlock—reduced a driver’s risk of committing a violation in the  first year of the program by approximately 64 percent. In 2011,  researchers published a study that replicated the 1999 study with a new  group of repeat offenders and found that participation in the ignition- interlock program still reduced drivers’ risk of re-arrest by 36 percent  while the ignition interlock was installed.
Research we identified on the effectiveness of ignition interlocks also  indicates that once the devices are removed, DWI arrest rates return to  pre-interlock rates.DWI offenses in New Mexico observed a reduction in re-arrest while the  ignition interlocks were installed, but in a period following removal of the  ignition interlock, there was no significant difference in DWI re-arrest rates  between offenders who had installed the ignition interlock and those who  had not. The literature review of 15 studies came to the same conclusion  that, following removal of ignition interlocks, re-arrest rates reverted to  levels similar to those for comparison groups.
section_title: Several Factors Contribute to Low Installation Rates
paragraphs: Although ignition interlocks have been shown to reduce arrest for alcohol- impaired driving while installed, researchers we interviewed estimated  that only 10 percent or less of DWI offenders ordered to install an ignition  interlock actually install one. NHTSA officials reported that between 15  and 20 percent of offenders arrested for DWI install ignition interlocks.  Estimates in individual states vary, with one study of DWI offenders in  California reporting about a 20 percent installation rate among those  ordered to install.Traffic Safety Commission reported 56 percent of DWI offenders ordered  to install an ignition interlock did so.
A recent evaluation completed for the Washington  However, estimating installation rates is imprecise. Federal officials told  us that it is difficult to accurately estimate installation rates because the  underlying data is often inconsistently maintained within and across  states. For example, NHTSA officials told us that in an ongoing study of  state ignition-interlock programs, they were able to identify only eight  states with sufficient data (e.g., the number of ignition interlocks ordered  and the number of DWI offenders who actually installed the ignition  interlocks) to estimate the program’s installation rate. As such, instead of  using the number of individuals ordered to install an ignition interlock, one  research group we spoke to used more easily-identifiable data such as  total population, total DWI arrests, or total DWI fatalities. The resulting  measure is referred to as an installation “in-use” rate—for instance, the  number of ignition interlocks in-use as a percentage of total population.
According to state officials, limited follow up and monitoring for  compliance and prerequisites for eligibility can hinder installation.
Limited follow-up and monitoring for offender compliance—According to  the literature review cited above, monitoring DWI offenders requires  substantial administrative resources. Officials from several states  included in our study said they do not have sufficient resources to follow  up with offenders to ensure ignition interlocks have been installed once  they have been ordered by a court or sanctioned by a state department of  motor vehicles. For example, state officials in Texas told us that courts  (i.e., judges) are often overwhelmed and do not have the resources to  follow up with offenders to ensure that an ignition interlock has been  installed or to monitor the results gathered by the ignition interlock  devices. According to New York officials, the caseloads of some  probation officers who may supervise DWI offenders are also heavy, and  some probation officers may not necessarily prioritize ignition interlock  compliance. Other law enforcement entities, even those that may lead or  operate the state’s ignition-interlock program, may not have the resources  to follow up on offenders to ensure ignition interlocks have been installed  and used as required. For example, Washington’s program is overseen  by the state highway patrol, but according to a senior Washington official,  the program lacks the resources to identify offenders who may be illegally  driving with a suspended license (i.e., those offenders who claim to be  waiting out the period of time that their license was suspended by not  driving at all) or driving without an ignition interlock.
Moreover, state officials we interviewed stated that limited followup and  monitoring contributed to offenders’ decisions to wait out ignition interlock  requirements. As mentioned above, the likelihood of being stopped for a  traffic violation is estimated to be less than 1 percent of those driving  while impaired by alcohol and research suggests that DWI offenders  continue to drive while their licenses are suspended. Officials from New  York described that a continuing challenge to increasing the number of  installed interlocks were DWI offenders attempts to wait out the period an  ignition interlock is required by temporarily signing over their vehicles to  friends or family. According to these officials, in New York, quarterly  inquiries are made to each of 62 counties’ probation departments to  check vehicle registrations of DWI offenders to address such attempts to  circumvent the state’s requirements for ignition interlocks. According to an  Illinois official, there is no requirement that an offender install an ignition  interlock in order to reinstate his or her licenseinterlock-restricted driving were undermined because many DWI  offenders believed that they could avoid being caught while driving  without an ignition interlock.
Prerequisites for eligibility—There are a variety of conditions a DWI  offender may be required to satisfy before he or she can receive interlock- restricted driving privileges.
Fees and penalties—In some states, offenders may have to pay fees  and penalties before they can be eligible to install an ignition interlock  and receive a restricted license. One study of Florida’s ignition- interlock program found that half of DWI offenders who had completed  their revocation period were still ineligible to install an ignition interlock  because they had not paid required fines and tickets. Similarly, an  Illinois official stated that a DWI offender would have to pay at least a  $380 fee in addition to any outstanding fees or penalties and enter  into a payment plan for any judgments resulting from the DWI  conviction in order to be eligible for interlock-restricted driving  privileges. Likewise, Connecticut requires offenders to pay a $100 fee  before an ignition interlock is installed. These fees and penalties are  in addition to any costs paid to the vendor for installation or lease of  the interlocks. Even in some states where there are indigent funds  available to assist offenders with the cost of ignition interlocks, some  of these fees imposed by the state may not be waived or reduced. In  Texas, one official described how mandatory license surcharges have  contributed to a substantial number of offenders driving illegally and  without insurance.
Treatment programs—In some states, offenders must complete  treatment programs before they are eligible to install an interlock and  have interlock-restricted driving privileges. In Illinois, offenders may be  required by a hearing officer or judge to enter or complete treatment,  in conjunction with installing an interlock, as conditions for being  granted a restricted drivers license. Likewise, in New York, officials  noted that some jurisdictions will not allow offenders to obtain their  licenses until treatment has been completed.
section_title: Limited Research Exists on Which Program Characteristics Could Improve Installation or Overall Program Effectiveness
paragraphs: Research supports the effectiveness of ignition interlocks in combating  impaired driving while they are installed, but limited research exists on  how to improve installation rates.
Two studies of programs in U.S. counties where judges required stricter  penalties for those not installing an ordered ignition interlock found a  higher percentage of offenders installed the ignition interlock. According  to a 2001 study, a court in Hancock County, Indiana, had required  installation of interlocks for all offenders using the threat of jail or  electronically monitored house arrest for non-compliance since 1997. The  study estimated that 62 percent of DWI offenders installed an ignition  interlock. A 2010 NHTSA evaluation of the New Mexico ignition-interlock  program found that 71 percent of convicted DWI offenders installed an  interlock in Santa Fe County, where judges made house arrest the  alternative to ignition interlock installation. In cases where DWI offenders  pleaded they had no vehicle, the judge required them to wear an  electronic monitoring bracelet. According to a 2013 MADD report based  on workshops with state officials and stakeholders from more than 30  states, imposing harsher sanctions could be a strategy for increasing  installation rates. One state official we interviewed described that  mandating alcohol monitoring as an alternative to installing an interlock  would be effective in increasing the installation rates.
One study suggested that requiring an ignition interlock for license  reinstatement following a DWI could improve installation rates. As  mentioned above, one of the ways a DWI offender can avoid installing an  interlock is by simply waiting out the ordered suspension period and not  driving during that time. Yet research suggests that many DWI offenders  drive during a suspension period. However, if a state has a separate administrative requirement through the department of motor vehicles, for  example, the offender cannot simply wait out the suspension period and  will have to install an ignition interlock in order to reinstate his full license.  A 2013 study on a Florida state requirement that DWI offenders install an  ignition interlock for at least 6 months in order to fully reinstate their  license observed that nearly 100 percent of offenders eligible to install an  interlock actually did so. According to state officials, New Mexico and  Washington have a similar license reinstatement requirement.
NHTSA is currently working with the Preusser Research Group (PRG) to  conduct a study on factors that could help states improve installation  rates. This research is being supported jointly by NHTSA and the CDC,  through a cooperative agreement with GHSA, which in turn contracted  with PRG to examine state ignition-interlock program characteristics— such as state laws, penalties, monitoring, or other factors—that were  associated with higher ignition interlock use. NHTSA officials said they  expect this report to be issued by late summer 2014.
subsections: section_title: Characteristics That Could Reduce Re-arrest during and after Interlock: Monitoring, Length of Installation, and Treatment
paragraphs: A randomized controlled trial of DWI multiple offenders in Maryland  observed that closer monitoring of offenders’ breath tests into the  interlock device improved compliance with the ignition-interlock program.  Closer monitoring consisted of reviewing breath test data and sending  letters to offenders informing them of the results and consequences. The  control group was subject to the standard Motor Vehicle Administration  monitoring, which did not include any specific procedures for monitoring  offenders. For example, the Motor Vehicle Administration took no action  when offenders in this group disconnected the interlock or logged  numerous breath tests at or above the limit of the ignition interlock. The  authors found that the closely monitored group had significantly fewer  initial breath test failures when attempting to start their vehicles than the  control group did. The authors also observed that ignition interlock  disconnects (e.g., tampering with the device) and retest failures were  lower for the closely monitored group as well, although these latter  differences were not statistically significant. Through the GHSA study  mentioned above, NHTSA officials told us that NHTSA and the CDC hope  to identify state’s ignition-interlock program characteristics, such as  monitoring, that may be associated with lower re-arrests. NHTSA officials  said this study should be completed by 2015.
We identified one study on the impact of varying lengths of ignition- interlock installation on DWI re-arrest. The study compared the results of  the Maryland’s two randomized controlled trials mentioned above (2011  and 1999) in order to determine whether the later 2-year administrative  ignition-interlock program was more effective in reducing recidivism than  the earlier 1-year interlock program. The 2011 study did show a  significant reduction in re-arrest even after the interlock was removed, a  result that the authors attributed to the extension of the interlock period  from 1 year to 2 years, although other differences in the two randomized  controlled trials, such as increased monitoring, were noted as well.  Despite this research, authors of the literature review mentioned above  noted that research currently provides little guidance on the ideal length  of interlock program participation. Research and interviews we conducted  suggests that most states require installation for at least 5 months.
Authors of two of these studies, conducted in Canada, noted that the BAC results  cannot be matched directly to the offender, but believe this limitation is mitigated by  findings from other studies that show that primarily the offenders are the ones driving the  interlocked vehicles. Authors of the other two studies noted that the vendor data they used  contained no demographic information and so they were not able to distinguish between  types of offenders. effect of a Florida state law that required alcohol treatment for DWI  offenders who fail a certain number of breath tests on their installed  ignition interlocks. CDC officials told us the results of this study would be  published in 2015 at the earliest.
section_title: NHTSA Provided Assistance to States for Ignition-Interlock Programs, but Some State Officials Questioned NHTSA’s Implementation of MAP-21 Grant
paragraphs: NHTSA offered a variety of assistance—including guidance, technical  assistance, research, and education—to help states establish and  improve their ignition-interlock programs, including the new ignition- interlock grant established by MAP-21. State officials who administered  ignition-interlock programs confirmed that NHTSA’s activities were  helpful. However, some officials questioned NHTSA’s implementation of  the ignition-interlock grant program because the states that exempted  certain offenders from installing interlocks were disqualified. According to  some state officials, exemptions are seldom used in practice, but are  important to maintain because they facilitate the ability of offenders to  work.
subsections: section_title: NHTSA Assisted States in Their Efforts to Implement Ignition-Interlock Programs
paragraphs: NHTSA offered a variety of assistance to help states establish and  improve their ignition-interlock programs. Specifically, NHTSA developed  and shared guidance, issued technical specifications, sponsored research  studies, collaborated with industry experts, and funded technical  assistance. It also administered and oversaw grants to states.
Guidance: Since 2008, NHTSA has published reports highlighting  key features of state ignition-interlock programs, including most  recently the 2013 guideline for a model ignition-interlock program.general, these reports provide information about ignition-interlock  program features and highlight issues that states should consider as  they put together or further refine their ignition-interlock programs.
Technical Specifications: In 1992, NHTSA published technical  model specifications for ignition interlocks that describe how ignition  interlock devices should perform and indicate how they can be  calibrated to meet uniform standards. In May 2013, NHTSA revised  the model specifications to address the rapid technological  innovations in the industry that had occurred since the original  publication. State ignition-interlock program administrators used these  model specifications to certify interlock devices offered by  manufacturers and ensure vendors and installers meet uniform  performance standards.
Research: NHTSA funds research studies that assess and provide a  more scientific basis for assertions about the effectiveness of ignition  interlock devices. Since 2009, NHTSA has funded and published a  number of studies and reports on ignition interlocks, including the  ongoing studies mentioned above on factors that could help states  improve installation rates or program characteristics related to lower  re-arrest rates.
Collaboration: NHTSA, either directly or through grants to other  organizations, brought stakeholders and experts together to share  information and collaborate on specific ignition-interlock program  projects. For example, in 2007, NHTSA funded an expert panel to  gather views about the effectiveness of ignition interlocks in  preventing impaired driving offenses; the views were published in a  2010 NHTSA report. In 2010, NHTSA and GHSA jointly hosted a  national ignition interlock summit, extending invitations to state  highway safety representatives and ignition-interlock program  administrators from all 50 states, interlock manufacturers,  researchers, and national organizations. NHTSA published a report  summarizing the summit in 2011. NHTSA also signed a cooperative  agreement with MADD for the organization to hold a series of ignition  interlock institutes across the U.S. between August 2009 and October  2012. The institutes were designed to bring together teams of people  and various agencies that are involved with some component of their  state ignition-interlock program in order to identify program  improvements.
Technical Assistance: In 2007, NHTSA entered into the first of two  cooperative agreements with TIRF to support the development of a  curriculum about ignition-interlock programs and to provide direct  assistance to states that seek to improve their ignition-interlock  programs. At the request of a state’s highway safety office, TIRF  consultants review the state’s ignition-interlock program, analyze the  program’s processes, and identify possible solutions for any  weaknesses. For example, in 2009, TIRF examined Illinois’ ignition- interlock program and identified a number of program strengths and  challenges. TIRF recommended that the state develop a process for  limiting the number of offenders who can opt out of the interlock  program, among other things. NHTSA’s cooperative agreement with  TIRF to provide technical assistance ends in August 2017.
Grants Administration: NHTSA also assisted state officials to apply  for DOT safety grants, such as the impaired driving countermeasures  grant, that can be used for their state’s ignition-interlock program. For  example, the agency held webinars and conducted other outreach to  educate states about the requirements of the new ignition-interlock  grant program.
State officials indicated that NHTSA’s actions assisted them in  implementing and further refining their ignition-interlock programs. For  example, two state officials noted that by attending conferences  sponsored by NHTSA they were able to leverage the experiences of other  states whose programs were more mature. Others noted that NHTSA’s  regional staff were readily available to answer questions and provide  advice and technical assistance. State officials also mentioned that they  used NHTSA’s ignition-interlock reports and guidance, such as the 2013  Model Guidelines report, to identify ways to strengthen their programs.
section_title: Some State Officials Questioned NHTSA’s Implementation of the New Grant
paragraphs: State officials questioned how NHTSA implemented one aspect of the  new ignition-interlock grant program; specifically that states did not qualify  for funding if they included exemptions in their alcohol ignition-interlock  programs. As described previously, states qualify for this grant by  requiring that all individuals convicted of a DWI offense be limited to  driving motor vehicles equipped with an ignition interlock. Under NHTSA’s  implementation regulations, states must require that the ignition interlock  be used for a minimum period of 30 days. As implemented by NHTSA,  states whose ignition-interlock programs allowed DWI offenders to drive  vehicles without an ignition interlock for work and medical reasons did not  qualify for the grants because their programs were not considered  mandatory for all such convicted individuals. Officials from New York,  Illinois, Washington, and Arizona indicated that NHTSA disqualified their  state because of the employer vehicle exemptions to their state’s ignition- interlock requirements. Illinois and New York officials stated that although  their state’s statutes allow exemptions, their programs typically grant few  exemptions compared to the number of ignition interlocks installed, and  the officials did not believe that exemptions substantially diminished the  effectiveness of their ignition-interlock program. However, state officials  noted they did not track the specific number of employer vehicle  exemptions that have been granted. For example, in New York, employer  vehicle exemptions are filed at the county level, not at the state level (i.e.,  with a state level department), and the state has little ability to access the  data in order to estimate the number of employer vehicle exemptions that  had been granted or compare this to the number of ignition interlocks  ordered.
NHTSA officials stated that they based their implementation of the  ignition-interlock grant on the plain meaning of the authorizing language  in MAP-21, which did not include any reference to exemptions or  exclusions. In responding to our draft report, the Department of  Transportation (DOT) provided a document that contained information on  states’ ignition-interlock laws. Specifically, NHTSA’s Digest indicated  that as of May 2012 at least 5 states allowed exemptions for employer  vehicles, and additional states had other factors that would prevent them  from qualifying for the ignition-interlock grant. NHTSA officials noted that  the MAP-21 grant represents a high bar for many states. Based on  experience in reviewing state impaired driving laws, NHTSA officials  recognized that many states would have to change existing laws to apply  to first time offenders and eliminate exemptions. Few states were  expected to qualify in the grant’s first years because it would be difficult  for state legislatures to change their ignition interlock laws in that time  frame. Further, NHTSA officials noted that the agency did not receive  comments from states related to exemptions during the public comment  period for the interim final rule.
Some state officials noted that it would be challenging to change their  laws to qualify for the ignition-interlock grant. First, officials from several  states told us that there is a lack of political support to put in place  requirements for first time offenders or to eliminate exemptions. State  officials from two states reported that their legislatures would not want to  impede employment of offenders, particularly in a poor economic climate  and given the expanse of areas in states that are rural, which makes  driving a necessity for daily life. Some state officials also pointed out that  the small size and short term nature of the grant funding did not support  making changes to their states’ ignition-interlock programs to qualify for  the MAP-21 ignition-interlock grant program.
Despite these challenges, two state legislatures changed their laws to  eliminate exemptions to qualify for the ignition-interlock grant in fiscal year  2014. During the first year of the grant—fiscal year 2013—only 2 states  out of 14 that applied qualified for the grant. Most of the states that did not  receive the grant were disqualified due to employer exemptions. State  legislatures in Arizona and Washington were able to eliminate employer  exemptions and other disqualifying factors from their laws in order to  qualify for the grant in fiscal year 2014, bringing the total grant recipients  to four that year. Because the ignition-interlock grant is relatively new, the  extent to which additional state legislatures would be willing or able to  modify their laws to qualify for the grant is unclear.
section_title: Concluding Observations
paragraphs: Ignition interlocks are one promising tool states can use to combat  alcohol-impaired driving. However, in order to be effective, the devices  must first be installed in vehicles and several factors—including limited  monitoring and eligibility prerequisites—can hinder installation even when  DWI offenders are ordered to use ignition interlocks. Ongoing and  planned research by NHTSA and others may shed light on actions state  officials can take to increase installation rates and otherwise improve the  effectiveness of their ignition-interlock programs. The MAP-21 ignition- interlock grant also has the potential to encourage the increased use of  ignition interlocks by providing funds to states that require the use of an  ignition interlock for all individuals convicted of a DWI offense. In the first  2 years of the grant program, few states applied for the grant and of  those, most were disqualified because of exemptions that allowed DWI  offenders to drive employer-owned vehicles without ignition interlocks.  Following the first grant year, two state legislatures modified their state  ignition-interlock laws to eliminate employer and other exemptions,  thereby qualifying for the MAP-21 grant in 2014. The extent to which  other states may follow suit is unclear. Some state officials noted that  even though these exemptions are not widely used, this option is critical  to allow DWI offenders to retain their jobs, particularly in rural areas or  areas without public transportation. For such states, the incentive and  relatively limited funding offered by the grant is not likely to outweigh the  challenges of changing state ignition-interlock laws to eliminate  exemptions.
section_title: Agency Comments
paragraphs: We provided a draft of this report to DOT for review and comment.  Included in the draft report was a recommendation that the Secretary of  Transportation provide Congress with information about the extent to  which states’ ignition interlock laws allow exemptions. This  recommendation was intended to provide Congress with more complete  information as it considers reauthorizing surface transportation programs,  including the ignition-interlock grant program. On June 11, 2014, the  Deputy Director of Audit Relations transmitted DOT’s comments by email.  In responding to our draft report, DOT officials expressed concerns about  this recommendation and provided additional information that addressed  our recommendation. Specifically, DOT provided the Digest of Impaired  Driving and Selected Beverage Control Laws, which is a compilation of  comprehensive information on states’ impaired-driving laws. We  concluded that the Digest includes sufficient information to provide an  overview of the extent to which state laws allow exemptions and  addresses our proposed recommendation. Therefore, in light of the new  information that DOT provided, we withdrew our recommendation. DOT  also provided technical corrections, which we incorporated as  appropriate.
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If you or your staff have any questions about this report, please contact  me at (202) 512-2834 or flemings@gao.gov. Contact points for our  Offices of Congressional Relations and Public Affairs may be found on  the last page of this report. GAO staff who made key contributions to this  report are listed in appendix III.
section_title: Appendix I: Objectives, Scope, and Methodology
paragraphs: The objectives of our review were to determine (1) what is known about  the effectiveness of ignition interlocks in reducing alcohol-impaired driving  and (2) the extent to which the National Highway Traffic Safety  Administration (NHTSA) has assisted states in implementing ignition- interlock programs, including the Moving Ahead for Progress in the 21st  Century Act (MAP-21) ignition-interlock grant program.
To identify what is known about the effectiveness of ignition-interlock  programs, we conducted a literature search for studies that analyzed  relationships between ignition interlock devices or programs and alcohol- impaired driving outcomes, including DWI arrest and DWI fatality. We  started with a 2010 NHTSA report “Key Features for Ignition Interlock  Programs,” which cited 15 studies and highlighted programs and program  features that are believed to be best able to serve traffic safety interests,  including reducing alcohol-impaired driving. We then identified additional  existing studies from peer-reviewed journals, government reports, and  conference papers based on searches of various databases, such as  ProQuest, MEDLINE, and Transportation Research International  Documentation. Search parameters included studies across the U.S. and  in specific states and those on specific interlock program components,  such as mandatory for first and repeat offenders and length of installation  required. These parameters resulted in 280 abstracts, which we narrowed  to 96, in part by cross-referencing the list with Web of Science, a resource  that identifies highly cited articles. We also conducted interviews with  organizations that conduct research on ignition interlocks, such as the  Pacific Institute for Research and Evaluation, and asked them to  recommend additional research.
From these multiple sources, we identified 25 peer-reviewed articles,  government reports, and conference papers between 1990 and 2013 that  were relevant to our research objective on the effectiveness of ignition  interlocks in reducing alcohol-impaired driving. To assess the  methodological quality of the selected studies, we performed an initial in- depth review of the findings, and then a GAO methodologist performed an  independent assessment of the study’s methodological soundness and  confirmed our reported analysis of the finding. One limitation is that the  majority of studies we identified did not randomly assign participants to  the ignition interlock; therefore there remains the potential for selection  bias, as individuals who agree to install an interlock may be inherently  different from individuals who do not agree. Additional limitations related  to the body of literature we reviewed include the lack of a national study  on interlock effectiveness, a lengthy time period over which the studies  were conducted (between 1990 and 2013), and the reliance of DWI arrest  as a proxy for alcohol-impaired driving. Despite these limitations, our  review of the literature did provide support for the effectiveness of ignition  interlocks while installed.
We supplemented our synthesis by interviewing three of the studies’  authors who had each contributed to multiple studies. We also conducted  interviews with NHTSA officials, as NHTSA has contracted out some  published and ongoing research on the effectiveness of ignition  interlocks. We also discussed program effects with state ignition-interlock  program administrators from the 10 states we included in our review (as  discussed below) and with NHTSA officials who were knowledgeable  about NHTSA-funded published and ongoing research on the  effectiveness of ignition interlocks.
To identify the types of assistance that NHTSA provides to states to help  them establish and implement their ignition-interlock programs, we  interviewed NHTSA officials about their activities and reviewed reports  describing NHTSA’s ignition interlock-related research, technical  assistance, and conferences. For both objectives, we interviewed  representatives from safety advocacy organizations such as the  Governors Highway Safety Association and Mothers Against Drunk  Driving. We also interviewed traffic safety, criminal justice, department of  motor vehicles or licensing, and law enforcement officials from a  nongeneralizable sample of 10 states. The selected states—Arizona,  Connecticut, Illinois, Montana, New Mexico, New York, Pennsylvania,  South Carolina, Texas, and Washington—were chosen to reflect a mix of  states that applied and did not apply for, as well as, states that qualified  and were disqualified from the MAP-21 ignition-interlock grant program.  To further select among states, we identified states with high DWI fatality  numbers in 2012 (the most recent year for which data are available) and  DWI fatality rates (alcohol-impaired fatalities per 100-million vehicle-miles  traveled) as calculated and categorized by NHTSA as high-, mid-, and  low-range states. We also factored in different types of programs  (judiciary, administrative, and hybrid); states with low DWI fatalities or  rates; and states with rural areas and tribal authorities, in selecting our  state sample.
Although the information gathered from these 10 states are  nongeneralizable, it provided insights about the extent of NHTSA’s  ignition interlock-related assistance, including its implementation of MAP- 21 ignition-interlock grant program, and the ignition interlock-related  research that states had conducted or participated in. In each state, we  obtained information about the state’s ignition interlock laws and program  as well as any challenges in applying or qualifying for the MAP-21  ignition-interlock grant program. We also asked state officials about  NHTSA’s other ignition-interlock related assistance.
We conducted this performance audit from July 2013 to June 2014 in  accordance with generally accepted government auditing standards,  Those standards require that we plan and perform the audit to obtain  sufficient, appropriate evidence to provide a reasonable basis for our  findings and conclusions based on our audit objectives. We believe that  the evidence obtained provides a reasonable basis for our findings and  conclusions based on our audit objectives.
section_title: Appendix II: Studies on Ignition-Interlock Effectiveness
paragraphs: Beck, Kenneth H., William J. Rauch, Elizabeth A. Baker, and Alian F.  Williams. “Effects of Ignition Interlock License Restrictions on Drivers With  Multiple Alcohol Offenses: A Randomized Trial in Maryland.” American  Journal of Public Health 89(11) (1999): 1696-1700.
Bjerre, Bo. “Primary and secondary prevention of drinking and driving by  the use of Alcolock device and program: the Swedish experience,” in  Alcohol Ignition Interlock Devices, Volume II: Research, Policy, and  Program Status 2005. ed. Paul Marques (Oosterhout, Netherlands:  International Council on Alcohol, Drugs and Traffic Safety (ICADTS),  2005), 11-24.
Coben, Jeffrey H., and Gregory L. Larkin. “Effectiveness of Ignition  Interlock Devices in Reducing Drunk Driving Recidivism.” American  Journal of Preventive Medicine, 16(1S) (1999): 81-87.
DeYoung, David J., Helen N. Tashima, and Scott V. Masten. “An  Evaluation of the Effectiveness of Ignition Interlock in California” in  Alcohol Ignition Interlock Devices – Volume II: Research, policy, and  Program Status 2005. ed. Paul Marques (Oosterhout, Netherlands:  International Council on Alcohol, Drugs and Traffic Safety (ICADTS),  2005), 42-52.
Elder, Randy W., Robert Voas, Doug Beirness, Ruth A. Shults, David A.  Sleet, James L. Nichols, and Richard Compton, Task Force on  Community Preventive Services. “Effectiveness of Ignition Interlocks for  Preventing Alcohol-Impaired Driving and Alcohol-Related Crashes. A  Community Guide Systematic Review.” American Journal of Preventative  Medicine 40(3) (2011): 362-376.
EMT Group. “Evaluation of the California ignition interlock pilot program  for DUI offenders.” A report prepared for The California Department of  Alcohol and Drug Programs and The California Office of Traffic Safety,  1990.
Jones, Barnie. “The Effectiveness of Oregon’s Ignition-interlock program.”  Paper presented at the 12th International Conference on Alcohol, Drugs,  and Traffic Safety, Cologne, Germany, September 28-October 2, 1992.
Marine, William. “High-tech solutions to drinking and driving: evaluation of  a statewide, voluntary alcohol ignition-interlock program.” Final grant  report. University of Colorado Health Sciences Center (2001).
Marques, Paul R., A. Scott Tippetts, and Robert B. Voas. “Comparative  and joint prediction of DUI recidivism from alcohol ignition interlock and  driver records.” Journal of Studies on Alcohol, 64(1) (2003): 83-92.
Marques, Paul R., Robert B. Voas, Richard Roth, and A. Scott Tippetts.  Evaluation of the New Mexico Ignition-interlock program. A report  prepared at the request of the National Highway Traffic Safety  Administration, 2010.
Marques, Paul R., A. Scott Tippetts, and Robert B. Voas. “The Alcohol  Interlock: An Underutilized Resource for Predicting and Controlling Drunk  Drivers.” Traffic Injury Prevention, 4:S1 (2006): 5-11.
Morse, Barbara J. and Delbert S. Elliott. “Effects of Ignition Interlock  Devices on DUI Recidivism: Findings From a Longitudinal Study in  Hamilton County, Ohio.” Crime & Delinquency 38 (2) (1992): 131-157.
Popkin, Carol Lederhaus, J. Richard Stewart, Jo Beckmeyer, and Carol  Martell. “An evaluation of the effectiveness of interlock systems in  preventing DWI recidivism among second-time DWI offenders.” Paper  presented at the 12th International Conference on Alcohol, Drugs, and  Traffic Safety, Cologne, Germany, September 28-October 2, 1992.
Raub, Richard A., Rov E. Lucke, and Richard Wark. “Breath alcohol  ignition interlock devices: controlling the recidivist.” Traffic Injury  Prevention 4 (2003):199 –205.
Rauch, William J., Eileen M. Ahlin, Paul L. Zador, Jan M. Howard, and G.  Doug Duncan. “Effects of administrative ignition interlock license  restrictions on drivers with multiple alcohol offenses.” Journal of  Experimental Criminology 7 (2011): 127-148.
Roth, Richard, Robert Voas, and Paul Marques. “Mandating Interlocks for  Fully Revoked Offenders: The New Mexico Experience.” Traffic Injury  Prevention, 8 (2007): 20-25.
Tippetts, A. Scott, and Robert B. Voas. “The effectiveness of the West  Virginia interlock program.” Journal of Traffic Medicine 26 (1998):19-24.
Vanlaar, Ward, Anna McKiernan, and Robyn Robertson. “Behavioral  Patterns of Interlocked Offenders: Phase II.” Traffic Injury Research  Foundation (2013).
Vanlaar, Ward, Robyn Robertson, Desirée Schaap, and Jan Vissers.  “Understanding Behavioural Patterns of Interlocked Offenders to Inform  the Efficient and Effective Implementation of Interlock Programs: How  Offenders on an Interlock Learn to Comply.” Traffic Injury Research  Foundation (2010).
Vezina, L. “The Quebec alcohol ignition-interlock program: impact on  recidivism and crashes.” Proceedings of the 16th International  Conference on Alcohol, Drugs and Traffic Safety, Montreal, Canada,  August 4-9, 2002.
Voas, Robert B., Anthony S. Tippetts, and Milton Grosz. “Administrative  Reinstatement Interlock Programs: Florida, A 10-Year Study.” Alcoholism:  Clinical and Experimental Research 37(7) (2013): 1243-1251.
Voas, Robert B., Kenneth O. Blackman, A. Scott Tippetts, and Paul R.  Marques. “Evaluation of a program to motivate impaired driving offenders  to install ignition interlocks.” Accident Analysis and Prevention 34 (2002):  449-455.
Voas, Robert B., Paul R. Marques, A. Scott Tippetts, and Douglas J.  Beirness. “The Alberta interlock program: The evaluation of a province- wide program on DUI recidivism.” Addiction 94(12) (1999): 1849-1859.
Willis, C., S. Lybrand, and N. Bellamy. “Alcohol ignition-interlock  programmes for reducing drink driving recidivism (Review). The Cochrane  Database of Systematic Reviews (2004): 1-20.
Zador, Paul L., Eileen M. Ahlin, William J. Rauch, Jan M. Howard, and G.  Doug Duncan. “The effects of closer monitoring on driver compliance with  interlock restrictions.” Accident Analysis and Prevention 43 (2011): 1960- 1967.
section_title: Appendix III: GAO Contact and Staff Acknowledgments
subsections: section_title: GAO Contact
section_title: Staff Acknowledgments
paragraphs: In addition to the contact above, Sara Vermillion (Assistant Director);  Melissa Bodeau; Russell Burnett; Leia Dickerson; Sarah Farkas; Geoffrey  Hamilton; Kirsten Lauber; Gail Marnik; Josh Ormond; Friendly Vang- Johnson; and Elizabeth Wood made key contributions to this report.