Traffic safety meta-analysis of reversible lanes.

A meta-analysis was performed to review the potential effects of reversible lanes on traffic safety. A systematic review resulted in ten U.S studies, with 155 estimates of safety effects, that were selected for inclusion in the analysis. These studies employed either a simple before-after comparison or a cross-sectional comparison methodology. Study results were extracted by transforming the collision rates and frequencies of these studies into a log-odds ratio. The results of the meta-analysis suggest that the odds of a collision occurring are 30.9% higher for roads with reversible lanes when compared to roads without the treatment. The odds of a property-damage-only collision are predicted to be 16.6% higher, and injury collisions are predicted to be 34.9% higher with reversible lanes compared to no-treatment. The odds of a collision occurring during the peak period are expected to be 46.2% higher, while the odds of an off-peak period collision occurring are expected to be 12.8% higher. These results were statistically significant, with the exception of the off-peak period collision result. A meta-regression was performed, which regresses variables related to study type, collision type and operational characteristics of the study locations on the extracted log odds ratio. Peak period operations were positively and significantly correlated with an increase in crashes. Presence of left-turn restrictions and/or delineator/barrier were negatively correlated with crashes, whereas the presence of dynamic traffic control and static traffic control were positively correlated with crashes. Finally, cross sectional studies tend to find greater effects than before-after studies.

Expression of focal adhesion kinase in uveal melanoma and the effects of Hsp90 inhibition by 17-AAG.

INTRODUCTION: Focal adhesion kinase (FAK) is implicated in tumor progression and metastatic cascade, and has been shown to be overexpressed in a variety of human cancers. However, the role of FAK in human uveal melanoma (UM) is not well defined. The purpose of this study was to evaluate the expression of FAK in UM tumors and normal eyes, and to determine the effect of Hsp90 inhibition on FAK expression in UM cells. METHODS: FAK expression was assessed in 39 UM specimens, FAK[pY397] expression was assessed in 51 UM specimens, and both FAK and FAK[pY397] expression were assessed in 20 normal eyes. The expression of FAK and FAK[pY397] was detected by Western blot in five UM cell lines after treatment with 10 µmol/L of 17-AAG. RESULTS: FAK was positive in 87.2% and FAK[pY397] in 90% of UM specimens. Low FAK expression was detected in non-tumor structures and in normal eyes. The cell lines with the most proliferative, invasive phenotype (92.1, SP6.5 and MKT-BR) displayed high expression of FAK[pY397], and the levels of FAK and FAK[pY397] were decreased in the presence of 17-AAG starting with 24 h of exposure. CONCLUSION: FAK and FAK[pY397] were overexpressed in human UM tumors compared to normal ocular tissue and high levels of FAK[pY397] were seen in the most aggressive UM cell lines. Hsp90 inhibition led to downregulation of FAK expression. We propose a role for FAK in the pathogenesis of UM. Future studies are needed to explore the use of Hsp90 inhibitors as a feasible approach for modulating FAK in UM.

Severity of motorcycle crashes in Calgary.

Motorcycle riders would be more vulnerable in the event of a crash because of their lack of protection which would often result in them suffering more severe injuries than car drivers. This paper estimated three crash severity models to identify factors that contributed to increasing the severity of motorcycle involved crashes in the Canadian City of Calgary. We found that results from the ordered logit model, heterogeneous choice model and partially constrained generalized ordered logit model produced estimates that were very similar which attested to their robustness. Injury severity tended to increase in neighborhoods with loops and lollipops types of streets or involved right-angle and left-turn-across-path crashes, a truck, unsafe speed or alcohol use but tended to decrease if the crash occurred in parking lots or during winter, involved a van or male rider, or a rider following-too-closely to the vehicle in front.

Effect of street pattern on the severity of crashes involving vulnerable road users.

Road crashes not only claim lives and inflict injuries but also create an economic burden to the society due to loss of productivity. Although numerous studies have been conducted to examine a multitude of factors contributing to the frequency and severity of crashes, very few studies have examined the influence of street pattern at a community level. This study examined the effect of different street patterns on crash severity using the City of Calgary as a case study. In this study, street pattern is classified into four categories: grid-iron, warped parallel, loops and lollipops, and mixed patterns. Their effects on injury risk are examined together with other factors including road features, drivers' characteristics, crash characteristics, environmental conditions and vehicle attributes. Pedestrian and bicycle crash data for the years 2003-2005 were utilized to develop a multinomial logit model of crash severity. Our results showed that compared to other street patterns, loops and lollipops design increases the probability of an injury but reduces the probability of fatality and property-damage-only in an event of a crash.

Effects of roadside memorials on traffic flow.

Despite their growing popularity in North America, little research has been conducted on understanding the effects of roadside memorials on drivers' behaviour. In this study, we examined the short-term effects of roadside memorials on traffic speed and headways on a high speed intercity freeway as well as its long-term effect on traffic speed on a high speed urban freeway. Our study found that the placement of roadside memorials did not have any significant effect on traffic speeds or headways, either in the short or long term. Therefore, concerns about the negative effects on driver behaviour were not supported by this research, at least with regards to speeding and following too closely. However, no positive effects on safety were found either.