The Oregon Department of Transportation (ODOT) identified bicycle and pedestrian crashes as a key safety focus area within Oregon’s Strategic Highway Safety Plan and sought to develop a plan to reduce frequency and severity of those crashes on all roadways throughout Oregon. Kittelson & Associates, Inc. (KAI) worked with ODOT to develop a Pedestrian and Bicycle Safety Implementation Plan that identified systemic, low-cost countermeasures and prioritized locations for implementation of the countermeasures. Priority implementation locations were developed using two complementary systemic safety analysis methods: one targeted at locations with a history of fatal and severe crashes, and the other focused on locations with high risk of pedestrian and bicycle crashes. The risk-based systemic safety methodology, promoted by FHWA, was applied due to the low frequency of pedestrian and bicycle crashes. The Implementation Plan will inform the allocation of approximately $4 million in funding for pedestrian and bicycle projects on all roads throughout the state and presents a repeatable process that can be adopted and customized by other state agencies.

Background

To evaluate Complete Street implementations that covary, the present paper aims to: 1) explore the development of typologies of intersections; and 2) examine how these typologies relate to traffic safety.

Methods

The study site is a five-mile segment in Los Angeles County, California. Multiple indicators of environmental features were collected in 2012 and were included in a latent analysis. Latent classes were then analyzed as a predictor of the number of pedestrian injuries/fatalities and injuries/fatalities for all modes in separate models using negative binomial regression and controlling for exposures. Injuries/fatalities represent the most recent 3 years of crash data available surrounding the environmental data collection (2009-2014). We also examined the role of alcohol.

Results

For a relatively short segment of an urban corridor, we identified two distinct classes of intersections. One class was more complete with respect to pedestrian features but was also associated with indicators of increased potential conflict and was predictive of higher overall injuries/fatalities for all modes. This class also had higher pedestrian volumes but was not predictive of higher pedestrian injuries/fatalities in the final models. The alcohol involvement in crash injuries at these locations did not differ by intersection class but was positively associated with injuries/fatalities for all modes and with severe/fatal injuries for pedestrians in the final models.

Conclusions

Identifying typologies can be used to understand the combination of features and prioritize locations for treatment. While Complete Streets may help counter pedestrian injury trends, the efforts captured in this data are insufficient for municipalities aiming for Vision Zero. Ideally, future research can examine these intersections after the implementation of additional improvements in order to isolate treatment effects. These findings suggest additional intersection countermeasures are needed, in addition to efforts to address social problems such as alcohol use and traffic safety.

Horizontal gene transfer via plasmids could favour cooperation in bacteria, because transfer of a cooperative gene turns non-cooperative cheats into cooperators. This hypothesis has received support from theoretical, genomic and experimental analyses. By contrast, we show here, with a comparative analysis across 51 diverse species, that genes for extracellular proteins, which are likely to act as cooperative 'public goods', were not more likely to be carried on either: (1) plasmids compared to chromosomes; or (2) plasmids that transfer at higher rates. Our results were supported by theoretical modelling which showed that, while horizontal gene transfer can help cooperative genes initially invade a population, it has less influence on the longer-term maintenance of cooperation. Instead, we found that genes for extracellular proteins were more likely to be on plasmids when they coded for pathogenic virulence traits, in pathogenic bacteria with a broad host-range.

This report presents the results from a multiyear effort to develop and test performance measures for evaluating the impact of landscaping and roadside features on pedestrian and bicyclist safety and mobility and economic vitality for Caltrans’ urban arterial network.  The first phase of the study was a literature review, and the second phase focused on developing performance measures. The third and fourth phases focused on testing the proposed performance measures consisting of an infrastructure analysis, policy review, safety analysis and a pedestrian and bicyclist intercept survey on two urban corridors in California. The results of the fieldwork indicate that the majority of the proposed performance measures are valid and ready for adoption by Caltrans.   The remainder of the measures require additional testing to produce conclusive results. The study also revealed that drivers, pedestrians, bicyclists, and transit users all request similar roadside design features to improve their perceptions of traffic safety, suggesting that transportation agencies maybe able to target a few specific improvements for maximum benefit to all user groups. Finally, the study found that the cities with the most developed pedestrian and bicyclist policies and plans seemed to have commensurate pedestrian and bicycle infrastructure on the ground, suggesting that the policies and plans have a tangible impact on eventual development.