Robinson, Ralph; Dion, Francois
The Multipath Signal Phase and Timing (SPAT) Broadcast Project demonstrates a Safe Green Passage traffic signal application that provides speed guidance to an approaching driver so that a vehicle may safely pass through the green phase of an upcoming traffic signal. This is accomplished by the signal system’s ability to send SPAT information to approaching vehicles even when they are several miles or multiple signals away. This project was developed in partnership with the Institute for Information Industry, a Taiwan ITS consortium, the Michigan Department of Transportation (MDOT), and the University of Michigan Transportation Research Institute (UMTRI). The Institute for...
Winkler, C. B.
UMTRI has completed an experimental program to determine the inflation pressure required to fail a sample of thirty individual 16 inch light truck tires when those tires are mounted on 16.5 inch wheels. It is possible to improperly installed a 16 inch tire (metric 215/85, in this case) on a 16.5 inch tire wheel. When this is the case, the tire bead may make and air tight seal against the wheel, even though the bead is not properly seated. If inflation pressure is than elevated, the improper seating of the tire can generate excessive stresses in the bead wire, eventually...
Winkler, C. B.
This is the final report of an experiment done by UMTRI to determine the inflation pressure required to fail 16 inch light truck tires, when improperly mounted on 16.5 inch wheels. In an interim report titled "Report on Failure Testing of Thirty Tires" UMTRI reported on the test results of thirty tires fro six different manufactures. In this final report, the test results of twelve more tires from two additional manufactures are also considered. It is possible to improperly mount a 16 inch tire (metric 215/85, in this case) on a 16.5 inch tire wheel. When this is the case,...
Karamihas, Steven M.; Senn, Kevin
This study examined the roughness and roughness progression of 21 test sections on the LTPP SPS-2 site in Arizona over the first 16 years of the experiment. The site included 12 test sections from the standard experiment and 9 supplemental test sections selected by the Arizona Department of Transportation.
Traditional profile analyses revealed roughness caused by transverse and longitudinal cracking on some test sections and some localized roughness caused by built-in defects. However, the analyses showed that curl and warp contributed
to, and in some cases dominated, the roughness on many of the test sections. In addition, roughness did not increase steadily...
This study examined the changes in the U.S. in vehicle fuel economy, distance travelled,
and vehicle load (occupants carried) between 1970 and 2010, and the effects of those changes on the amounts of fuel consumed. All light-duty vehicles were included in the analysis.
The results indicate that during the 40-year period examined, vehicle distance travelled
increased by 155%. However, because vehicle load decreased by 27%, occupant distance travelled increased by only 84%. Vehicle fuel economy (of the entire fleet of light-duty vehicles) improved by 40%. However, because of the decrease in vehicle load, occupant fuel economy improved by only 17%. As a consequence...
This study examined the relationship between GDP and vehicle sales in 48 developed and developing countries during the years 2005 through 2011. The countries examined were Argentina, Australia, Austria, Belgium, Brazil, Canada, Chile, China, Colombia, Czech Republic, Denmark, Egypt, Finland, France, Germany, Greece, Hungary, India, Indonesia, Ireland, Israel, Italy, Japan, Luxembourg, Malaysia, Mexico, the Netherlands, New Zealand, Norway, Pakistan, the Philippines, Poland, Portugal, Romania, Russia, Slovakia, Slovenia, South Africa, South Korea, Spain, Sweden, Switzerland, Thailand, Turkey, the United Kingdom, the United States, Uruguay, and Venezuela. The annual vehicle sales in the individual countries ranged from about 16 thousand to about...
Eby, David W.; Molnar, Lisa J.; Kostyniuk, Lidia P.; St. Louis, Renee M.; Zanier, Nicole; Kellman, Daniel
The populations of the United States (US) and Michigan are aging. This demographic trend will continue to have a significant impact on society for the next few decades, particularly in the area of safe mobility in rural areas. As the population of Michigan’s rural older adults continues to grow, it is becoming increasingly crucial that the Michigan Department of Transportation (MDOT) understand the mobility needs and issues of rural older adults, including the issues faced by Indian Tribes in rural Michigan, and be proactive in addressing these needs and issues in their activities. This project provides the background and suggestions...
The objectives of this study were (1) to estimate the effectiveness of seatbelts and driver
airbags for mitigating medium- and heavy-truck driver injuries, and (2) to discuss the
implication of these estimates with respect to truck-driving conditions in the U.S. and China.
U.S. data showed that fatal or serious injuries of truck drivers are caused mainly by
rollover, collision with a light vehicle or another truck, or collision with fixed objects.
Rollover crashes account for most serious injuries, and pose the highest injury risk per crash. By controlling for the difference in crash-type distributions between trucks and light vehicles, seatbelts were estimated to be about...
Luoma, Juha; Sivak, Michael
This study compared road safety and related factors in the U.S. with those in
Sweden, the United Kingdom, and the Netherlands, in order to identify actions most likely
to produce casualty reductions in the U.S. The reviewed topics were basic country
statistics, road fatalities and various fatality rates, national road-safety strategies, and
selected road-safety issues. The main differences concerned structural and cultural factors
(such as vehicle distance driven), and procedural factors (such as road-safety strategies and
targets, alcohol-impaired driving, exceeding speed limits, and use of seat belts).
The main recommendations for improving road safety in the U.S. are as follows:
(1) lower states’ BAC limits to 0.5 g/l...
Schoettle, Brandon; Sivak, Michael
This study examined road safety in two European megacities, London and Paris. Patterns of fatal crashes (both cities) and all crashes (London only) were compared with crash patterns for each respective nation as a whole. The data for London and the U.K. came from the Department for Transport, and included detailed crash data from 2005 to 2011. The data for Paris and France came from ONISR, and included summaries of fatal crashes from 2007 to 2011.
The results indicate that population demographics and traffic crashes in these two megacities tend to differ in numerous aspects when compared to the respective national...
Palamara. Peter; Molnar, Lisa; Eby, David; Kopinanthan, Chelvi; Langford, Jim; Gorman, Jessica; Broughton, Michelle
This report documents the investigation of the relationship between risky driving behaviours and other health risk behaviours among youth and young adults, locally and elsewhere. Literature reviews were undertaken of the development of risk taking; young driver behaviour; substance use including alcohol, smoking and illicit drugs; unsafe sex, and self-harm and suicide to identify and compare common risk factors for local youth and those elsewhere. Countermeasures that can be adopted from other risk taking areas and applied to young driver risk taking were also reviewed. A number of recommendations were provided for potential interventions to reduce risk taking on the...
For the past several years, we have calculated (on a monthly basis) the average, salesweighted fuel economy of all light-duty vehicles (cars, pickup trucks, vans, and SUVs) sold in the U.S. The results indicate that, from October 2007 to September 2012, the average fuel economy has improved by 18%, from 20.1 mpg to 23.8 mpg. This brief note quantifies the consequences of this improvement on overall fuel consumption and vehicle emissions.
Because of their improved fuel economy, the vehicles sold since October 2007 saved a
cumulative total of about 6.1 billion gallons of fuel—equivalent to the current total consumption of all vehicles...
From 2005 to 2011, we have witnessed an unprecedented trend: Road fatalities in the U.S. have dropped by 26%. However, there are some indications that a reversal of this trend might be beginning to take place.
This brief note argues that the economic downturn contributed substantially to the large magnitude of the reduction in road fatalities. Consequently, the reversal of the reduction in fatalities should not be a surprise as the economy is beginning to improve. The note concludes with several recommendations for public-policy makers.
Sivak, Michael; Bao, Shan
This study examined road safety in the two U.S. megacities, New York and Los Angeles.
Patterns of fatal and all crashes in these megacities were compared with those for the entire U.S. (Also included were data for the two respective states, New York and California.) The data on fatal crashes came from the Fatal Analysis Reporting Systems, and the data on all crashes from the General Estimates System and the states of New York and California. The period examined was 2002 through 2009.
The results indicate that crashes in the two megacities tend to differ in numerous aspects
from typical crashes in the...
Reed, Matthew P.; Blower, D. F.; Flannagan, Michael J.
This report presents the results of a three-part study of truck driver exterior vision and its safety consequences. In part one,
crash data are analyzed to document vision-related truck crash issues. About 20% of truck-initiated crashes occur in
configurations in which limitations to truck driver vision may have been an important factor contributing to the crash.
Right-going lane changes and turns account for more than half of these crashes. On average, right-going truck-initiated
crashes are about 4.5 times more likely than left-going crashes. Non-motorists killed in startup and right-turn crashes were
nearly all adults and tend to be older the pedestrians struck in other crash...
Sivak, Michael; Schoettle, Brandon
This report presents a time-series analysis of changes in road safety in the U.S. from
the public-health point of view. A 50-year period is examined, from 1958 to 2008. The
emphasis is on the changes by decades in fatalities per population across different age groups.
The main findings are as follows. First, from 1958 to 2008, the overall fatality rate per population decreased by 40%. Second, the decrease in the rate was age dependent (with the largest decreases for the youngest and the oldest, and smallest decreases for the middle-aged). Third, the overall fatality rate increased from 1958 to 1968, but it decreased...
Lin, Brian T. W.; Green, Paul; Kang, Te-Ping; Lo, Ei-Wen
Older drivers stop driving for several reasons, including being overwhelmed by the
workload of the primary driving task. Unfortunately, most driving studies (including
those measuring driver distraction and overload) describe workload qualitatively, not
quantitatively. A simple way to quantify workload is to ask drivers to rate it while
showing them anchor clips (e.g. this scene is 2, that scene is 6) to aid repeatability.
To validate new anchor clips of road scenes for workload ratings, 16 subjects (8
age 18-30, 8 age >65) drove simulated expressway scenarios and rated the workload
of 28 scenarios relative to the new anchor clips, and for 10 of them that duplicated
Green, Paul; George, Jason; Jacob, Renju
A total of 21 young people completed a 35-multipart question survey about their use of cell phones. Of them, 15 completed logs of every call for a month and answered over 20 multipart questions about each call (depending on the call), covering a total of 1,168 cell phone calls, about half of which were made while driving. The purpose of this study was to identify typical conditions of cell phone use and determine how driving and non-driving conditions differ so studies of cell phone safety and usability can examine test conditions that closely approximate real use.
Calls were more likely to...
Green, Paul; Shah, Reshma
Delphi Electronics & Safety
Mayer, Ken; Friedman, Dana; Green, Paul
There has been considerable public debate as to whether people should be allowed to use cell phones while driving. In several countries, this debate has led to restrictions on cell phone use while driving. Japanese data suggests that answering a call might be the most dangerous task, followed by dialing. Several questions were therefore selected for further investigation.
1. How does the dialing device and its location affect task time, errors, driving
performance, and ratings of workload?
2. How does the location of the display (especially head-up displays) affect those
3. For various control-display combinations, how are those measures affected by