Friday Seminar - Robert Campbell on Failure to Yield: A Framework for Evaluation of Compliance Measures

Traffic Circle Trails

This week's Friday TRANSOC Seminar features Robert Campbell, Ph.D. candidate, University of California, Berkeley, presenting "Failure to Yield: A Framework for Evaluation of Compliance Measures."

In this presentation, we explore the safety problem of drivers violating yield signs in a freeway context. Drivers violating traffic controls is a common problem, and agencies have a collection of strategies that they often use to address the problem. These include increasing the size of the traffic control, adding an advanced warning upstream, installing pavement markings, or using LEDs to capture drivers' attention. As common as these (and other) compliance measures are, however, no research has been done to properly evaluate how they compare in terms of effectiveness.

In cooperation with Caltrans, two different compliance strategies—increasing the size of the control, and adding supplemental pavement markings—were implemented on Interstate 10 in Los Angeles so that the effectiveness of each could be measured in the field. Although our experiments involve yield sign violations, the insights obtained can be adapted to other contexts as well, such as pedestrian crosswalks or turn prohibitions at intersections.

We will explore the outcomes of these two experiments and, using a method we have developed to allow for responsible comparisons of effectiveness, will come to conclusions about the performance of each one. Our analysis offers insights into the mechanisms behind the observed behavioral response that occurs in drivers over time after a strategy is implemented (including what happens in the often-ignored "unstable" or "novelty" phase), which we can then use to inform our assessments of each compliance strategy. Our results will reveal flaws with the conventional before-and-after approach used to evaluate compliance measures, and will show how such errors can be avoided or corrected.

 The seminar will be held in 534 Davis Hall from 4:00-5:00 on Friday, April 27. Please join us for a TRANSOC-sponsored Cookie Hour in the ITS Library, 412 McLaughlin, from 3:30-4:00.


Friday Seminar - Karthik Sivakumaran on Access and the Choice of Transit Technology

MBTA RTS bus 0026

This week's Friday TRANSOC Seminar features Karthik Sivakumaran, Ph.D. candidate, University of California, Berkeley, presenting "Access and the Choice of Transit Technology."

An urban transit system can be made more efficient by improving the access to it.  Efforts in this vein often entail the provision of greater mobility, as when high-speed feeder buses are used to carry commuters to and from trunk-line stations.  Other efforts have focused on the creation of more favorable land-use patterns, as occurs when households within a Transit-Oriented Development (TOD) are tightly clustered around trunk stations.  The efficacy of these mobility and land-use solutions are separately examined in the present work.  To this end, continuum approximation models are used to determine the design parameters that minimize the generalized costs to both the users and the operators of hypothetical transit networks.

Though idealized, these assessments furnish useful and very general insights.  They confirm that if transit is accessed slowly on foot, as is commonly assumed in the literature, then the optimal spacings between routes, and between the stations along those routes, are quite small.  This typically places capital-intensive rail systems at a competitive disadvantage with transit systems that feature buses instead.  However, these spacings expand when access speeds increase.  Hence, we show how Bus Rapid Transit (BRT) and Metro-Rail can become a preferred option for trunk-line service when accessed via faster-moving feeder buses.

By comparison, the influence of altered land use patterns brought by TODs is less dramatic when all users walk to Metro-rail stations.  We find that clustering households around these stations justifies larger spacings between them, but produces only modest reductions in generalized costs.  This is because the larger spacings penalize transit users who reside outside of the TODs.

The seminar will be held at 4:00pm in 534 Davis Hall. Don't forget about Cookie Hour in the library at 3:30! See you here.

Friday Seminar: Anurag Pande presents "Traffic crash patterns: What can we learn from retailers?"


This week's TRANSOC Friday Seminar features Anurag Pande presenting, "Traffic crash patterns: What can we learn from retailers?"

 Data mining applications are becoming increasingly popular for many applications across a set of very divergent fields. Analysis of crash data is no exception. Association analysis or market basket analysis is used by retailers all over the world to determine which items are purchased together by consumers. It is then applied to stock items (e.g., Salsa and Chips) close to each other. In traffic safety research based on association rule mining, crashes are analyzed as supermarket transactions to detect interdependence among crash characteristics. The results from the analysis include simple rules that indicate which crash characteristics are associated with each other. Results will be presented from two of research articles in which this application is demonstrated using crash data from the state of Florida.

The seminar will be at 4:00pm in 534 Davis Hall as usual. Don't miss Cookie Hour in the library at 3:30!


New Global BRT Database

Estação e vermelhão

This week was launched by the Bus Rapid Transit Center of Excellence and EMBARQ. The site acts a clearinghouse for data from BRT systems all over the world. You can see performance indicators by country or city, such as passengers per day, number of corridors, and legth. Check it out and let them know what you think.

Friday Seminar: Shomik Mehndiratta on Sustainable Low-Carbon City Development in China

Shanghai Urban development centre on people's square

This week's TRANSOC Friday Seminar, which is happening today (4/6), features Shomik Mehndiratta from the World Bank. He will present, "Sustainable Low-Carbon City Development in China."

This talk summarizes the key messages of a recently released book that examines, through the specific lens of low-carbon development, the lessons of the World Bank’s activities related to urban development in China.  Amid unprecedented levels of urban migration, rapidly increasing incomes, double digit annual growth in motorization and expanding city forms, many Chinese cities are already on a high carbon-emission growth path. With China set to add an estimated 350 million residents to its cities over the next 20 years, the case for urgent action is strong.

On one hand, China's cities are already reacting to ambitious commitments their leaders have made to reduce the carbon and energy intensity of the economy and transition to a low-carbon growth path.  The country's current (12th) Five-Year Plan includes, for the first time ever, an explicit target to reduce carbon intensity by 17 percent by the end of 2015. However, the imperative to reduce carbon intensity is only one of many competing priorities for government officials in the midst of unprecedented urbanization, modernization, and economic development.

What are the choices Chinese cities are making?  And what are the implications?  Achievements and challenges to low-carbon city development in China will be discussed with a particular focus on transport, land-use and urban spatial development.

The seminar will be at 4:00pm in 534 Davis Hall as usual. Don't miss Cookie Hour in the library at 3:30!

Pardon Our Mess....

ITS Library Stacks in Flux

Some big changes are happening here at the ITS Library over the next few months and things are going to get messy. We've started by ripping up the carpet, removing some bookselves, and moving books over to our new annex in O'Brien Hall. While we're processing our collection for the move, finding things on the shelf might be a little tricker, so don't hesitate to ask us for help.

We'll keep you all updated as things keep moving. Thank you for your patience while we transition.

Spring Break!


It might not look like Spring here in Berkeley, but it is Spring Break this week! We have quite a few special projects in the works, so we'll be closed this week to tackle them.

We'll resume normal hours on Tuesday April 3.

GPS-Based Household Travel Survey from Cincinnati


A recent TRB blurb pointed to this new study from the Ohio DOT that explores the feasibility of using small, personal GPS devices to conduct household travel surveys, and how  that data is comparable to household travel surveys conducted through questionnaires. They conclude:

The primary conclusion to be drawn from this research is that it is feasible to undertake a GPS-only household travel survey, achieving a high standard of representativeness for the sample, while imputing mode and purpose at a sufficiently accurate level to support modeling work. The high level of accuracy attained in this survey for imputing mode and purpose with 96 percent on mode and around 90 percent on activity (other than detailed breakdowns of the “other” category) is far superior to self-report surveys. The richness of the “ground-truthing” of time, location, distance, speed, and route information from this survey surpasses what can be achieved from any other form of survey.

The final report can be found here.

Friday Seminar: Dr. Venky Shankar on Considerations Regarding Design Variations on Safety

4th & Howard

Today's Friday Seminar from TRANSOC features Dr Venky Shanker P.E. presenting "Considerations Regarding Design Variations on Safety."

This talk will present some thoughts on the consideration of design variations in the analysis of network safety, with a focus on strategic guidance on probing the effects of design variations in depth. Strategic guidance will be described through example models estimated empirically using statistical methods. The talk reflects ongoing research activity and integrates insights from the speaker's prior experience in decision-making in design policy matters at state governmental levels.

The seminar will be held at 4:00pm in 534 Davis Hall. Don't forget about Cookie Hour in the library at 3:30! See you here.

More on PPPs and Road Financing

PA Turnpike tilt-shift

Yesterday we talked about Britain's proposed privatization of their transport infrastructre and made an error when we said the Pennsylvania Turnpike was leased to a private company. In 2007 bidding was opened on the Turnpike and in 2008 the highest bid was received from Spanish firm Abertis Infraestructuras, but ultimately the plan failed. Currently the Turnpike is managed by a state-operated commision that "receives no state or federal taxes to operate and maintain its toll road system." The Pew report, Driven by Dollars, outlines several of the problems that were a part of the leasing proposal and calls for a more open process and transparency.

As funding sources dry up, such as the transportation bill now stuck in gridlock on Capitol Hill or depleted state budgets, transportation agencies will have to come up with new methods of financing which has an increasing interest on private money. The 2011 book Road to Renewal examines private investment in transportation projects from around the world, outlining what works and what doesnt for PPPs as well as how to protect public interests. Louise Nelson Dyble has a recently published article "Tolls and Control: The Chicago Skyway and the Pennsylvania Turnpike" which compares the two plans and raises questions about impact on future transportation planning policy.



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