Evaluation

Attribution of functional limitation to cancer decreases in the year following breast cancer diagnosis in older patients

Sehl, Mary E.
Satariano, William A.
Ragland, David R.
Reuben, David B.
Naeim, Arash
2008

Objectives: To examine the prevalence of self-reported functional limitations in a breast cancer population, identify whether these reported limitations are attributed to breast cancer versus other coexisting illnesses, and examine how this attribution changes over time from early in treatment to 9 months later.

Design: Longitudinal, observational study.

Setting: Community dwelling adults in Detroit metropolitan area. Participants: 2033 participants (1011 breast cancer patients, 1022 controls) aged 40–84 years.

Measurements: Participants were asked about each of 23...

Using Variable Speed Limits To Reduce Rear-End Collision Risks Near Recurrent Bottlenecks

Li, Zhibin
Liu, Pan
Bigham, John M.
Ragland, David R.
2013

Rear-end collisions would occur if vehicle speeds decrease abruptly when encountering kinematic waves (KWs) emanating from active bottlenecks. This study aims to develop a control strategy in variable speed limits (VSL) to reduce rear-end collision risks near recurrent bottlenecks. Using the crash prediction model developed for rear-end collisions related to risky KWs, the effectiveness of VSL control strategies were evaluated in the cell transmission model (CTM). Several strategies were tested in sequence to determine the best case for risk reduction. Results of this study show that the...

Developing Safety Management Tools for State Departments of Transportation

Chung, Koohong
Grembek, Offer
Lee, Jinwoo
Choi, Keechoo
2013

Two safety management tools have recently been developed for the California Department of Transportation (Caltrans). One is the continuous risk profile (CRP) approach, which is a network screening procedure, and the other is the California Safety Analyst (CASA), a web-based application designed to assist state safety engineers in conducting safety investigations and in documenting their findings. This paper provides a qualitative description of the two tools and summarizes feedback from more than 100 Caltrans safety engineers who attended demonstrations of the web-based application....

A Multidimensional Clustering Algorithm for Studying Fatal Road Crashes

Fishbain, Barak
Grembek, Offer
2014

Road fatalities are rare outcomes of events that occur in a small time-space region. Although the exact chain of events for each fatality is unique, there are inherent similarities between road fatalities. The science of road safety is dedicated to identifying such similarities, mainly using statistical analysis tools. Researchers typically analyze patterns that emerge over space, such as hot-spot studies, or patterns that emerge over time, such as before-after studies. Traffic research enumerates 84 parameters that characterize a road fatality. A vast number of papers have tried to...

Crosswalk Confusion: More Evidence Why Pedestrian and Driver Knowledge of the Vehicle Code Should Not Be Assumed

Mitman, Meghan F.
Ragland, David R.
2014

Traffic safety researchers have long argued that driver behavior outweighs physical elements (such as road design) as a causal factor in motor vehicle collisions. A fundamental causal component of pedestrian—vehicle collisions is also behavior: that of the driver and that of the pedestrian. One determinant of this behavior may be whether the driver, the pedestrian, or both understand the motor vehicle code, which demarcates the right-of-way in pedestrian-vehicle interactions. That is, inappropriate or unlawful behavior may occur because the law is not understood or is misunderstood....

The Impact of Health Problems on Driving Status Among Older Adults

MacLeod, Kara E.
Satariano, William A.
Ragland, David R.
2014

Objective: This study assessed the impact of health problems on driving status (current driver vs. ex-driver) among older adults to identify which of those health problems have the greatest individual and population impact on driving cessation.

Methods: Data were from baseline and a 5 year follow-up wave of a longitudinal survey of adults aged 55 years and older (N¼1279). The impact of several health problems on driving status was assessed using a relative risk ratio and a population attributable risk percent. Analyses controlled for age, gender, and the presence of additional...

Relative Burden of Distracted Driving Fatalities by Characteristic

Griswold, Julia B.
Grembek, Offer
2014

We were glad to see discussion of the dangers of distracted driving to vulnerable road users in the article by Stimpson et al. in the November/December 2013 issue of Public Health Reports. However, we question the conclusion that pedestrian and bicyclist victims of distracted driving crashes are disproportionately nonHispanic white. This inference appears to be drawn from the results in Table 1 of the article, where the rates are calculated per one million total population, which fails to account for the different sizes of the populations of each race/ethnicity. To correctly evaluate the...

Crashes on and Near College Campuses: A Comparative Analysis of Pedestrian and Bicyclist Safety

Loukaitou-Sideris, Anastasia
Medury, Aditya
Fink, Camille
Grembek, Offer
Shafizadeh, Kevan
Wong, Norman
Orrick, Phyllis
2014

Problem, research strategy, and findings: College campuses are multimodal settings with very high levels of walking and biking in conjunction with high levels of vehicular traffic, which increases risks for bicyclists and pedestrians. In this study, we examine crash data (both police reported and self-reported) and urban form data from three U.S. campuses to understand the spatial and temporal distribution of crashes on the campuses and their immediate periphery. To account for underreporting of pedestrian and bicycle crashes, we developed and circulated an online survey, which helped...

Relative Vulnerability Matrix for Evaluating Multimodal Traffic Safety

Grembek, Offer
2015

The multimodal transportation network includes a mix of inherently different modes. In addition to differences in price, range, and comfort of travel, these modes differ in mass and velocity, which correspond to different orders of magnitude in the kinetic energy carried. This discrepancy in kinetic energy affects both the level of protection of each mode, and the level of damage it can inflict on users of other modes. Unfortunately, accounting for both sides of a crash is often overlooked. While the quantities and variables of collected data continue to increase, the analyses conducted...

Modeling Secondary Accidents Identified by Traffic Shock Waves

Wang, Junhua
Liu, Boya
Lanfang, Zhang
Ragland, David R.
2015

The high potential for occurrence and the negative consequences of secondary accidents make them an issue of great concern affecting freeway safety. Using accident records from a three-year period together with California interstate freeway loop data, a dynamic method for more accurate classification based on the traffic shock wave detecting method was used to identify secondary accidents. Spatio-temporal gaps between the primary and secondary accident were proven be fit via a mixture of Weibull and normal distribution. A logistic regression model was developed to investigate major factors...