Optimized Placement of Mounted Equipment within Patrol Vehicles during Side Impact Crashes

Sponsor: US Department of Justice

PI: John Hill

The primary purpose of this study is to further develop recommended safe zones for interior mounted equipment in police vehicles based on side impact crash testing. Current recommendations for the safe placement of equipment have been developed based on airbag deployment zones. These airbag deployment zones are published by vehicle manufacturers for both front and side impact airbags. The new safe mounting zones will be based not on airbag deployment, but rather on occupant trajectory during a crash.


2011 Michigan Seat Belt Observation Surveys

Sponsor: Michigan State Police

PI: John Hill

This report summarizes the findings of the statewide seatbelt survey completed in June following the May 2011 Click it or Ticket enforcement campaign.  191 Intersections were surveyed.  The overall seat belt use rate was 94.5%.  For the second survey in August, the seat belt use rate fell to 93.5%.  Additionally, information regarding cell phone use is contained in this report.  Cell phone use rate among drivers was 8.6% in June and 10.3% in August.  All data is organized by vehicle type, age, gender, race, and day and time.  Additionally, logistic regression models have been provided to identify the statistical significance of differences in seat belt use and cell phone use based on these characteristics.  Wayne County showed a significant increase in seat belt usage, and may be a case study for best practices.  With regard to cell phone usage, the survey identified Hispanics and females age 16‐29 as the primary users of cell phones while driving.


Identifying Cost and Funding Alternatives for Equipping Operating While Intoxicated Offenders with Ignition Interlock Devices

Sponsor:  Wisconsin Department of Transportation

PI:  John Hill

Ignition Interlock Devices (IID) have been used in multiple states to deter repeat operating while intoxicated (OWI) offenders from further offenses.  It has been found in the state of California that a group of offenders who had an order to use an IID had a reduction in future crash rates of 24 percent, while slight changes were seen in those that were not ordered the use of an IID.  Those drivers who installed the IID also had a lower rate of future DUI convictions.   A major issue with IIDs has been compliance.  Studies have shown that as few as 10% of drivers convicted of OWI and ordered to install an IID device, actually do so.

Research Objectives
– Identify and characterize OWI offenders in Wisconsin  and develop a 10 year forecast of overall
OWI arrests and arrests of particular high risk offenders.
– Estimate IID implementation costs based on the forecast model developed and determine the
overall affordability of IID devices for OWI offenders
– Identify potential funding sources to increase IID installations.

Information regarding over 200,000 OWI offenders in Wisconsin from 2005-2009 was analyzed.  Using a logistic regression model, characteristics of OWI offenders who were likely to repeat the offense within 1 or 2 years were identified.  Additionally, a 10 year forecast model was developed which was based on annual historical arrest levels over the past 20 years, as well as monthly vehicle miles travelled an d economic data over the past 5 years.  Using this information, along with cost data collected from interviewing IID manufacturers, the overall cost to equip the vehicles of future OWI offenders was collected.  Income levels of IID offenders were also modeled using an exponential distribution to determine what proportion of offenders may be unable to afford an IID.  Finally, an analysis of potential funding sources was conducted to determine if supplementing the cost of IIDs might be a feasible means of increasing IID order compliance.