Automobile-dependency as a barrier to vision zero, evidence from the states in the USA

With a traffic fatality rate of 10.6 per 100,000 as of 2013-more than triple that in the UK, the Netherlands, and Sweden-the United States has the worst traffic safety performance of all developed countries. Statewide variations are even more pronounced. North Dakota registers more than twice the national average and five times the rate of Massachusetts. We used panel models and annual data from 1997 to 2013 to capture the effect of seven separate sets of factors that influence traffic safety: exposure, travel behavior, socioeconomics, macroeconomics, safety policies, and mitigating factors such as health care. The results of our panel models and supplementary analysis of state effects show that two variables - Vehicle Miles Traveled and Vehicles per Capita-have the strongest impact on traffic fatality rates. This is closely followed by Infant Mortality Rates, the proxy that we used to represent the quality of health care. Policy levers such as Graduated Driver's Licenses (GDL) have improved safety, but to a limited extent. We also found that states with higher urban density and more walking are associated with lower traffic fatality rates. Taken as a whole, our findings suggest that if additional progress is to be made in reducing traffic fatalities, emphasis needs to move beyond simply focusing on policies such as GDL and seat belt laws, which have already been adopted by almost all jurisdictions across the United States. We need to also consider factors that focus on the type of urban form that we are creating to ensure that we are fostering environments that encourage multi-modal transportation such as walking to reduce the VMT and Vehicles per Capita, the two strongest predictors of traffic fatalities.

Progress towards zero, an international comparison: Improvements in traffic fatality from 1990 to 2010 for different age groups in the USA and 15 of its peers

INTRODUCTION

In January 2015, the United States Department of Transportation (USDOT) announced that the official target of the federal government transportation safety policy was zero deaths. Having a better understanding of traffic fatality trends of various age cohorts-and to what extent the US is lagging other countries-is a crucial first step to identifying policies that may help the USDOT achieve its goal.

METHOD

In this paper we analyze fatality rates for different age cohorts in developed countries to better understand how road traffic fatality patterns vary across countries by age cohort. Using benchmarking analysis and comparative index analysis based on panel data modelling and data for selected years between 1990 and 2010, we compare changes in the rate of road traffic fatality over time, as well as the absolute level of road traffic fatality for six age groups in the US, with 15 other developed countries.

RESULTS-CONCLUSIONS

Our findings illustrate tremendous variations in road fatality rates (both in terms of the absolute values and the rates of improvement over time) among different age cohorts in all of the 16 countries. Looking specifically at the US, our analysis shows that safety improvements for Youngsters (15-17 years old) was much better than for other age groups, and closely tracked peer countries. In sharp contrast, Children (0-14 years old) and Seniors (+65 years old) in the US, fare very poorly when compared to peer countries. For example, in 2010, Children in the US were a stunning five times more likely to experience a road traffic fatality than Children in the UK.

PRACTICAL APPLICATIONS

This startling statistic suggests an immediate need to explore further the causes and potential solutions to these disparities. This is especially important if countries, including the US, are to achieve the ambitious goals set out in Zero Vision initiatives.

Children's asthma hospitalizations and relative risk due to nitrogen dioxide (NO2): effect modification by race, ethnicity, and insurance status

BACKGROUND

This study explores the role of race, ethnicity, and insurance status in modifying the effects of air pollution on children's asthma hospitalizations in Phoenix, Arizona (US) between 2001 and 2003. While controlling for weather, interactions between nitrous dioxide (NO(2)) and race, ethnicity, and insurance status are used to predict relative risk for subgroups of children.

METHODS

The generalized logit regression model for nominal categorical data within a multinomial likelihood framework was used. This model is specifically suited to small counts and the reporting of 95% confidence intervals for the odds ratio of hospital admission for one group as compared to another. The odds ratio is known to approximate relative risk for rare events.

RESULTS

Several significant findings were found for race, ethnicity, and insurance status as modulators for the effect of NO(2) on children's risk for asthma hospitalization: (1) children without insurance have 1.4 (95% CI: 1.1-1.8) times higher risk of asthma admissions than those with private insurance at exceedances of 0.02 parts per million (ppm) of NO(2) above the seasonal mean; the same finding holds for children without insurance as compared to those with Medicaid; (2) black children have 2.1 (95% CI: 1.3-3.3) times higher risk of hospitalization than Hispanic children at seasonal mean NO(2) levels, but this disproportionate risk shrinks to 1.7 with exceedances of 0.02 ppm of NO(2) above the seasonal mean. Specific to finding (1) among those children without health insurance, Hispanic children have 2.1 (95% CI: 1.1-3.8) times higher risk of hospitalization than white children. Among all Hispanic children, those without health insurance have 1.9 (95% CI: 1.3-3.0) times greater risk than those with private insurance; the same finding holds for Hispanic children without insurance as compared to Hispanic children with Medicaid. Specific to finding (2), among children with private insurance, the disproportionate risk of black children as compared to Hispanic children is magnified by a factor of 1.3 (95% CI: 1.0-1.8) for exceedances of 0.02 ppm of NO(2) above the seasonal mean.

CONCLUSIONS

Although we cannot confirm a cause-effect relationship, this analysis suggests that increasing insurance enrollment for all children, and specifically Hispanic children, may reduce their disproportionate risk from exceedances of air pollution. There are few black children in Phoenix, so further studies are needed to investigate the increasing risk of black children with private insurance as compared to Hispanics at exceedances of NO(2).

Comparing the capitalisation benefits of light-rail transit and overlay zoning for single-family houses and condos by neighbourhood type in metropolitan Phoenix, Arizona

Light rail transit (LRT) is increasingly accompanied by overlay zoning which specifies the density and type of future development to encourage landscapes conducive to transit use. Neighbourhood type (based on land use mix) is used to partition data and investigate how pre-existing land use, treatment with a park-and-ride (PAR) versus walk-and-ride (WAR) station and overlay zoning interrelate. Hedonic models estimate capitalisation effects of LRT-related accessibility and overlay zoning on single-family houses and condos in different neighbourhoods for the system in metropolitan Phoenix, Arizona. Impacts differ by housing and neighbourhood type. Amenity-dominated mixed-use neighbourhoods-predominantly WAR communities-experience premiums of 6 per cent for single-family houses and over 20 per cent for condos, the latter boosted an additional 37 per cent by overlay zoning. Residential neighbourhoods-predominantly PAR communities-experience no capitalisation benefits for single-family houses and a discount for condos. The results suggest that land use mix is an important variable to select comparable neighbourhoods.