Kendra K. Levine's blog

On Ramp for d3.js - March 20th!

 

Do you want to use d3.js to make data visualizations to effectively communicate your research but don't know where to start? This Thursay, March 20th, in the Lower Level of the Blum Center join VUDLab from 6-9 PM for On Ramp for d3.js.

Our "On Ramp for d3.js" is designed to get people across disciplines the needed tools and know-how to create simple and easy-to-manipulate data visualizations. By the end of the night, we plan to have our participants complete two web-based visualizations and get the baseline tools needed to begin learning d3.js on a more serious level. Think of our event as your first crash course in creating interactive tools to show off your work! We will be providing food and soft drinks for everyone (don't worry... we got you).

Details of the event can be found here

New from FHWA: Human Factors Assessment of Pedestrian Roadway Crossing Behavior

2012 09 19 - 171 - DC - Connecticut Ave Candids

Earlier this year FHWA issued a new research report as part of their ongoing research on pedestrian and bicycle safety. In Human Factors Assessment of Pedestrian Roadway Crossing Behavior, researchers collected data and used it to create a predictive model of pedestrian behavior. 

More than half of pedestrian fatalities occur at unmarked locations away from intersections. However, little research has been conducted to understand why pedestrians cross roadways at unmarked locations. As a result, this study sought to better understand the environmental influences on both where and when pedestrians elect to cross the road. This report examines more than 70,000 pedestrian crossings at 20 different locations. The circumstances of those crossings (pedestrians yielding to vehicles, vehicles yielding to pedestrians, and evasive actions) were documented and analyzed. A model using environmental factors as inputs is provided to predict where (marked crosswalk intersection or outside the marked crosswalk) pedestrians will cross the road.

The full report can be found here

Travel Demand Forecasting: Beyond the models and into reality?

Chicago road network

Recently the State Smart Transportation Inivitiative (SSTI) asked if travel demand forecasts from U.S. DOT were accurate

Their answer is no

In the post, "U.S. DOT highway travel demand estimates continue to overshoot reality", Eric Sundquist examines the projections in FHWA's 2013 Conditions & Performance report. He finds that the estimates for VMT growth were 5-6% higher than reality. Concluding:

Had the report based estimates on more current historic data—e.g., VMT trends for 2003-13, which grew at one-fifth the USDOT’s 1995-2010 estimate—the cost estimates would have dropped by tens of billions more, reducing pressure on budgets while freeing up funds to bring the existing system to a state of good repair.

The accuracy of travel demand models and forecast predictions is not a new issue and more people are questioning the methodoloy. This year's TRB Annual Meeting featured a workshop on the issue The Next 50 Years in Travel Analysis: What We Don’t Know but Need to Know. The moderator, David T. Hartgen, mentioned a recent paper he wrote, "Hubris or humility? Accuracy issues for the next 50 years of travel demand modeling," in Transportation. Hartgen, examining 50 years of forecasting, describes problems with accuracy and ways to imrpove models. Definitely a paper worth reading. 

Friday Seminar: Planning, Design and Technical Aspects of Rail Transit Lines and Networks

Railing on Water

This Friday's Seminar is not to be missed. University of Pennsylvania Professor Vukan Vuchic, who wrote the book on urban transit, will present, "Planning, Design and Technical Aspects of Rail Transit Lines and Networks."

Growth of cities and increasing car ownership in recent decades have created a great need to build rail transit systems – LRT, Metros and Regional Rail. With their high-performance and high level of service, these modes compete well with private cars and serve large ridership. Their permanence influences urban form and land use development with high livability. The characteristics and roles of these three major modes of rail transit will be described. The alignments of their lines and networks will be reviewed. Positive and negative characteristics of different types of lines, such as radial, diametrical, circle, trunk/branch and others will be defined. This will lead to a comparison of two basic types on networks, those with integrated and with independent lines, illustrated by examples from many world cities. Current trends and likely developments in the roles and usage of different high-performance rail transit modes, such as “in-fill stations,” articulated metro cars, double-decker Regional Rail cars, Unattended Train Operation– UTO, will be reviewed. References will be made to BART development, innovations and experiences, as well as other rail systems in the Bay Area, such as MUNI and Caltrain.

The seminar takes place Friday March 7, 2014 from 4-5 PM in 534 Davis. TRANSOC Cookie Hour will be at 3:30 in the library. 

Everybody's a Tourist? Rethinking the Driver Population Factor

objects in mirror

A new paper, "Rethinking the Driver Population Factor," from ITS Berkeley's own Joshua Seeherman and Professor Alexander Skabardonis takes a look at the driver population factor currently used in the Highway Capacity Manual

Freeway analysis procedures in the widely used Highway Capacity Manual (HCM) include the input of a driver population factor (Fp), which allows the analyst to adjust the demand depending on the familiarity of drivers with the roadway. This adjustment is based on the assumption that unfamiliar drivers will drive at slower speeds with longer headways and that higher capacity would therefore be required. However, little research supports the use of the Fp, and the HCM cautions against the use of Fp unless the analyst is fairly certain the traffic stream is actually unfamiliar with the roadway. As an experiment, three bottlenecks in California were selected and analyzed during the weekday peaks and weekend afternoons in periods during which the traffic stream was likely to be nonlocal. The results showed that the changes in flow were minor at all three locations. Further research with additional sites and an increased awareness of the definition of familiarity will be required to confirm the results from this research.

The full paper can be found online in Transportation Research Record no. 2395 or you can look at the hard copy in the library. 

Friday Seminar: Some Approaches to Enhance Road Safety: Beyond Engineering Based Strategies

Tomorrow's ITS Friday Seminar is Dr. Shashi Nambisan, a professor at the University of Tennessee, presenting, "Some Approaches to Enhance Road Safety: Beyond Engineering Based Strategies"

Road safety is a significant concern to a broad range of stakeholders. Various approaches and strategies have been used to enhance road safety across the world. In this regard, the 4 Es used to characterize safety initiatives are Engineering, Education, Enforcement, and Emergency medicine. The developed nations have adopted a more comprehensive approach to incorporate the 4 Es, while the less developed nations focus primarily on engineering initiatives. The seminar will highlight some of the strategies adopted in Las Vegas, Nevada and across Iowa in the United States. These will be complemented with comments about challenges involved in improving overall road safety in Kerala, India. Further, examples of effective non-engineering based strategies will be presented. The seminar will also touch upon lessons learned from these experiences, and key considerations that are important for sustainable success of campaigns to enhance road safety.

The seminar will take place Friday, February 28, 2014 in 534 Davis from 4-5 PM. TRANSOC Cookie Hour will be in the library at 3:30.

Friday Seminar: Travel Time Reliability and Network Traffic Performance

Travel Times

This week's TRANSOC Friday Seminar features Professor Hani Mahmassani of Northwestern University presenting "Travel Time Reliability and Network Traffic Performance: Selected Highlights from Recent Research"

Reliability of travel time in traffic networks is affected by a variety of factors,some external (e.g. demand surges, weather) and others inherent to the behavior of the traffic stream, reflecting complex dynamics among interacting agents. Yet remarkably simple collective effects emerge when examining the relation between the standard deviation of the trip time per unit distance to the corresponding mean at the network level. We examine this relation for several networks using both simulated and actual data from vehicle probes. We connect this variance to other traffic variables defined at the network level, providing a simple characterization of travel time reliability as a function of density. We consider within-day and day-to-day variability and propose a compound gamma model to capture overall variation. To evaluate the reliability implications of different transportation options and operational strategies using simulation tools, a scenario-based approach is proposed and demonstrated.

The seminar takes place this Friday, February 21, 2014 from 4-5 PM in 534 Davis. Cookie Hour commences at 3:30 in the library.

Friday Seminar: The Cycling Gender Gap: What do Sex, Power, and Fashion Have to Do With It?

Bike4Life Oakland 2009

This week's TRANSOC Friday Seminar looks at gender and cycling. Professor Jennifer Dill of Portland Sate University will present, "The Cycling Gender Gap: What do Sex, Power, and Fashion Have to Do With It?"

In larger urban areas in the US, women make up only about one-third or fewer of the adults who bicycle for transportation. This is in contrast to major bicycling cities such as Copenhagen and Amsterdam where a gender gap in bicycling is non-existent. For cycling to make a major contribution to improving the sustainability of US urban areas, the gender gap must be addressed. This talk will discuss the history of women and the bicycle in the US, then draw upon national statistics and research from Portland, Oregon to explain why girls and women are not bicycling for transportation and what might change that.

The seminar will commence on Friday, February 14, 2014 from 4-5 PM in 534 Davis. Cookie Hour will take place at 3:30 in the library. 

What makes people walk more?

walk

A new article from PLoS One asks the question, "What makes people walk more?" Actually, in, Richard H. Glazer et al ask - "Density, Destinations or Both? A Comparison of Measures of Walkability in Relation to Transportation Behaviors, Obesity and Diabetes in Toronto, Canada"

The design of suburban communities encourages car dependency and discourages walking, characteristics that have been implicated in the rise of obesity. Walkability measures have been developed to capture these features of urban built environments. Our objective was to examine the individual and combined associations of residential density and the presence of walkable destinations, two of the most commonly used and potentially modifiable components of walkability measures, with transportation, overweight, obesity, and diabetes. We examined associations between a previously published walkability measure and transportation behaviors and health outcomes in Toronto, Canada, a city of 2.6 million people in 2011. Data sources included the Canada census, a transportation survey, a national health survey and a validated administrative diabetes database. We depicted interactions between residential density and the availability of walkable destinations graphically and examined them statistically using general linear modeling. Individuals living in more walkable areas were more than twice as likely to walk, bicycle or use public transit and were significantly less likely to drive or own a vehicle compared with those living in less walkable areas. Individuals in less walkable areas were up to one-third more likely to be obese or to have diabetes. Residential density and the availability of walkable destinations were each significantly associated with transportation and health outcomes. The combination of high levels of both measures was associated with the highest levels of walking or bicycling (p<0.0001) and public transit use (p<0.0026) and the lowest levels of automobile trips (p<0.0001), and diabetes prevalence (p<0.0001). We conclude that both residential density and the availability of walkable destinations are good measures of urban walkability and can be recommended for use by policy-makers, planners and public health officials. In our setting, the combination of both factors provided additional explanatory power.

You can read the full article here because PLoS One is Open Access. Hat tip to Streetsblog for posting this

Friday Seminar: Innovations in Traffic Safety Research

photoadayproject (44)

Tomorrow is Friday, which means there's another TRANSOC Friday Seminar taking place. This week features Professor Moshen A. Jafari of Rutgers University. He will present, "Innovations in Traffic Safety Research".

Traffic crashes and accidents at intersections, roundabouts and roadway segments result from many complex factors, but at a basic level, they are outcomes of the interactions among vehicles and other road users. Since few direct measurements of these interactions are available, engineers and planners instead attempt to understand them by studying crashes and accidents reports. As crashes account for a tiny fraction of safety conflicts, these reports fail to provide a full understanding of what is happening at the points of accidents. This is especially true of crashes involving pedestrians and bicycles, for which data are sparse, making it difficult to determine reliable patterns. In this talk we will present risk based traffic safety models using multiple data streams, including near miss data, systemic data, historical traffic accidents, and drivers’ naturalistic behavior data. We will also briefly discuss ongoing research at Rutgers on the development of Plan4Saefty software, which is currently being used by the State of New Jersey for traffic safety analysis and planning.

The seminar will be held Friday, February 7 2014 from 4:00-5:00 PM in 534 Davis Hall. Cookie Hour commences at 3:30 here in the library. 

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