Urban sprawl leads to more fatal crashes, while denser areas experience higher rates of accidents which cause injuries.

Is urban sprawl good for us? Recent years have seen a growing debate over the costs and benefits of urban sprawl compared with denser communities in areas such as public health and environmental sustainability. Using data from nearly 1,000 metropolitan counties across the U.S., Reid Ewing and Shima Hamidi examine the relationship between sprawl and fatal crashes. They find that while less dense areas tend to experience lower rates of fatal crashes, they have a greater number of crashes in total, as well as crashes which cause injury and property damage

Endangered by Sprawl: How Runaway Development Threatens America's Wildlife

Estimates the growth of land consumption in metropolitan areas over the next 25 years, investigates locally implemented strategies to protect natural lands from overdevelopment, and offers "smart growth" as an option for reducing suburban sprawl

The Regional Response to Federal Funding for Bicycle and Pedestrian Projects

Examines the efficacy of federal funding for non-motorized modes of transportation based on funding patterns across metropolitan regions, case studies of policies and projects, and an analysis of the funding's impact on bicycling and walking behavior

Assessing the Accuracy of Complex Refractive Index Retrievals from Single Aerosol Particle Cavity Ring-Down Spectroscopy

<p>Cavity ring-down spectroscopy (CRDS) of single, optically manipulated aerosol particles affords quantitative retrieval of refractive indices for particles of fixed or evolving composition with high precision. Here, we quantify the accuracy with which refractive index determinations can be made by CRDS for single particles confined within the core of a Bessel laser beam and how that accuracy is degraded as the particle size is progressively reduced from the coarse mode (>1 μm radius) to the accumulation mode (<500 nm radius) regime. We apply generalized Lorenz–Mie theory to the intra-cavity standing wave to explore the effect of particle absorption on the distribution of extinction cross section determinations resulting from stochastic particle motion in the Bessel beam trap. The analysis provides an assessment of the accuracy with which the real, <i>n</i>, and imaginary, κ, components of the refractive index can be determined for a single aerosol particle.</p> <p>Published with license by American Association for Aerosol Research</p> <p><a href="https://www.tandfonline.com/pb-assets/tandf/Migrated/UAST_VideoAbstract_Transcript.pdf" target="_blank">Read the transcript</a></p> <p><a href="https://vimeo.com/263371383" target="_blank">Watch the video on Vimeo</a></p

Does Compact Development Increase or Reduce Congestion?

The net effects of sprawl or compact development on area-wide traffic congestion have been a subject of debate among transportation researchers. This project aims to settle the debate using: Congestion data from the Texas Transportation Institute’s Urban Mobility Scorecard database; Compactness/sprawl metrics developed at the University of Utah. Compact development may help at the margin, but the greatest reduction in congestion appears to be achieved through expansion of surface streets and higher highway user fees

New Travel Demand Modeling for our Evolving Mobility Landscape

Conventional four-step travel demand modeling is overdue for a major update. The latest NITC report from University of Utah offers planners a better predictive accuracy through an improved model, allowing for much greater sensitivity to new variables that affect travel behavior. Specifically, it accounts for varying rates of vehicle ownership, intrazonal travel, and multimodal mode choices. Used by nearly all metropolitan planning organizations (MPOs), state departments of transportation, and local planning agencies in the United States, the importance of travel demand modeling for project selection cannot be overstated: They are the basis for forecasting future travel patterns and developing long-range regional plans

Compactness vs. Sprawl Revisited: Converging Views

This paper examines the relative merits of compact cities or urban sprawl (suburban settlement patterns) as a spatial solution to environmental problems (such as climate control), automobile dependence, economic development, infrastructure costs and the quality of urban life

Using XRD to Characterize Sediment Sorting in a Mars Analog Glacio-Fluvio-Eolian Basaltic Sedimentary System in Iceland

The martian surface has a primarily basaltic composition and is dominated by sedimentary deposits. Ancient layered sedimentary rocks have been identified across the planet from orbit, have been studied in situ by the Mars Exploration Rovers and the Mars Science Laboratory rover, and will be studied by the Mars 2020 rover. These ancient sedimentary rocks were deposited in fluvial, lacustrine, and eolian environments during a warmer and wetter era on Mars. It is important to study the composition of sediments in Mars analog environments to characterize how minerals in basaltic sedimentary systems are sorted and/or aqueously altered. This information can help us better interpret sedimentary processes from similar deposits on Mars and derive information about the igneous source rocks. Sediment sorting has been studied extensively on Earth, but not typically in basaltic environments. Previous work has addressed sorting of basaltic sediments through experimental techniques and in modern eolian basaltic systems and aqueous alteration in subglacial and proglacial environments. We add to this body of research by studying sediment sorting and aqueous alteration in a glacio-fluvio-eolian basaltic system in southwest Iceland