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Friday Seminar - Venky Shankar on Performance Oriented Modeling

This Friday's TRANSOC seminar features Dr. Venky Shankar, Associate Professor, Pennsylvania State University and Visiting Scholar, UC Berkeley, on "Towards a Statistical Basis for Performance Oriented Modeling of Highways - a Safety Perspective."

 

This talk will discuss a strategic approach to the development of a consistent modeling basis for the statistical analysis of highway safety. Barriers to the development of consistent bases will be discussed with respect to the statistical, computational and data considerations. This work is being performed as part of Dr. Shankar's sabbatical visit to UC Berkeley.

 

The Seminar is Friday, October 21, 4:00-5:00, 406 Davis Hall.

Ampelmännchen turns 50.

Berlin 2007: Ampelmann

50 years ago today, the most iconic traffic light for pedestrian crossings debuted in German Democratic RepublicAmpelmännchen or "Little Traffic Light Man." On this day in 1961, traffic psychologist Karl Peglau introduced the novel design to improve predestrian safety

 

In several studies, he concluded that many of the 10,000 traffic deaths between 1955 and 1960 could be attributed to one thing: Pedestrians had to follow the same traffic lights as cars. When it was foggy, the red-yellow-green lights did not offer sufficient orientation for visually impaired pedestrians. According to Peglau, they provided the opposite, and were a safety risk. He estimated the economic damages of this problem in the GDR reached up to 155 million deutsche marks in 1959.

"Clearly distinguishable guiding signals" were meant to address this. A friendly red man with thick, outstretched arms would prompt pedestrians to stop, and a lively green man in mid-stride would denote the appropriate time to walk. Peglau provided personal characteristics in order to "appropriately provoke the desired pedestrian behavior through emotion," giving them pug noses, fingers, ears and mouths.

 

After the Reunification of German, the iconic Ampelmännchen was quickly introduced to West Berlin and continues to be a symbol of the unified city. 

Friday Seminar - Weihua Gu on Capacity Models for Curbside Bus Stops

LACMTA

Tomorrow's TRANSOC Friday Seminar features Ph.D. candidate Weihua Gu presenting, "Capacity Models for Curbside Bus Stops with Multiple Berths."

When multiple bus lines merge at a busy, multi-berth bus-stop in a congested city, long bus queues might occur due to an inadequate number of berths.  Disruptive bus overtaking maneuvers and chaotic passenger boarding processes may therefore ensue at the stop.  To unveil the cause-and-effect relations behind this congestion, models are developed to predict the bus-carrying capacity for curbside bus-stops.  These capacities are functions of the stop’s number of bus berths, and other key operating factors.  An analytical solution is derived for a queueing model that describes the unique operating features of serial bus berths.  The results from these models show that conventional wisdom in this field is incomplete and incorrect in many instances.  The proposed models can provide practitioners better guidelines for choosing the number of berths to achieve a desired capacity at a curbside bus-stop.  The models also give insights to improve ways of operating the stop.  These ways include, but are not limited to, allowing or prohibiting bus overtaking maneuvers under certain circumstances, and strategies to manage passenger boarding and alighting processes.  Further, these bus-stop models can be applied to other serial queueing systems in the transportation field, including taxi queues, Personal Rapid Transit systems, and toll plazas with tandem booths.

The seminar will take place from 4-5 pm in 406 Davis on October 14. Please come to TRANSOC's Cookie Hour preceeding the seminar at 3:30 pm in the library. 

Unintended Consequences: Booting Hybrids from HOV Lanes Slows Traffic

 Hybrid car in the carpool lane, Institute of Transportation Studies, University of California, Berkeley

This past July, the California Clean Air Stickers for HOV Lanes program ended for hybrids. What was the effect of this change? How did it affect traffic flow and congestion? That question was investigated by ITS researchers Prof. Michael Cassidy and Kitae Jang, of the Volvo Center.  Their new ITS report, Dual Influences on Vehicle Speeds in Special-Use Lanes and Policy Implications, analysed traffic data and used models to calculate the impact of the added low-emissions vehicles on the other lanes. Cassidy told the Berkeley Newscenter:

“Our results show that everybody is worse off with the program’s ending,” said Cassidy. “Drivers of low-emission vehicles are worse off, drivers in the regular lanes are worse off, and drivers in the carpool lanes are worse off. Nobody wins.”

...

“As vehicles move out of the carpool lane and into a regular lane, they have to slow down to match the speed of the congested lane,” explained Jang. “Likewise, as cars from a slow-moving regular lane try to slip into a carpool lane, they can take time to pick up speed, which also slows down the carpool lane vehicles.”

The paper was also discussed by the New York Times, USA Today, and the LA Times

Get Down with Bicycle Safety

Avid readers know that this week was International Walk to School Day in the USA, part of the Safe Routes to Schools program. Bicycle safety has always been an important component of safe routes to schools, even way back in the 80s. Here's is an old school jam from an after school special circa 1989. You dig?

Word. Though safe bicycling is still important, even for adults. Listen to this rhyme king tell you all about the need for proper illumination. 

Stay safe out there. 

Friday Seminar: Mazyar Zeinali on Commercial Aviation and Climate Change

Airbus A380-800

This week's TRANSOC Friday Seminar is Mazyar Zeinali from the International Council on Clean Transportation presenting "Commercial Aviation and Climate Change: The Role of Technology."

The environmental impact of aviation has been of concern for several decades including specific concerns such as local air quality, impacts on Earth's protective ozone layer, and aircraft induced cloudiness. However, with the 1999 seminal publication by the Intergovernmental Panel on Climate Change (IPCC) entitled 'Aviation and the Global Atmosphere', significant concern has arisen both in aviation climate change impact and mitigation possibilities. To quantify expected return from future technology implementation (near to mid term), the International Civil Aviation Organizational (ICAO) commissioned and published a study conducted by a panel of independent experts (IEs). The IE technology scenarios included returns under typical/continuation of current business-as-usual practices and also accelerated implementation under added future regulatory pressure. The ICCT was a contributing organization to this ICAO study and Dr. Zeinali will present his findings and interpretations for specific technological packages envisioned by the panel and efficiency gains from implementing technology in tighter aircraft designs, better matching operational norms and patterns.

The seminar will take place October 7 from 4-5 PM in 406 Davis Hall. Cookie Hour will be at 3:30, as usual, in the library. 

International Walk to School Day and Safe Routes

going to school

Today International Walk to School Day in the USA. Did you know that? You probably did. Everyday can be walk to school day through the work of the Safe Routes to School program, a multidisciplinary coalition with members from transportation, public health, and housing. Their report, Getting Students Active through Safe Routes to School: Policies and Action Steps for Education Policymakers and Professionals, contains information about how schools can implementa a safe routes program and things to consider. The TransForm report, Bringing Safe Routes to Scale, which focuses on the Bay Area. SafeTREC researchers Jill Cooper and Tracy McMillan published a report last year that evaluated 10 low income schools

 

Petaluma Going Yellow for Left Turns

left turn signal

Yesterday the Press Democrat reported on Petaluma replacing the "left on green" signals with flashing yellow lights

The city will replace all or some of the protected-permissive signals at 26 intersections throughout town, while allowing a few to remain as is.

Some will include a signal new to California and what may be a first for Sonoma County — the flashing yellow left-turn arrow.

Petaluma Boulevard North at Magnolia Avenue/Payran Street had a “higher than expected collision experience involving left-turning vehicles,” Zimmer said.

In all four directions, the protected-permissive signals will be replaced with protected left-turn phasing, meaning left-turn drivers will see a progression of green, yellow and red arrows.

Then, once the intersection is cleared, a flashing yellow arrow will light, alerting drivers that they may proceed with caution with a left turn when oncoming traffic is clear.

The 2009 MUTCD includes languange about flahsing yellows for left turns (4D.17-4D.20). The topic is also discussed in NCHRP Report 493: Evaluation of Traffic Signal Displays for Protected/Permissive Left-Turn Control. While Petaluma is the first city in California to implement this sort of signal, it has been catching on across the nation. Next year, two different research projects investigating the impacts of flashing yellows on protected left turns should be completed. One is Evaluation of Flashing Yellow Arrows (FYA) for Protected/Permissive Left Turn (PPLT) Control from Bradley University for the Illinois DOT. The other is Field Study of Driver Behavior at Flashing Yellow Arrow vs Green Ball Permitted Left-Turn Indications by CTS of the University of Minnesota for the ITS JPO of RITA

 (Hat tip to @thedotreport)

 

Raising Speed Limits: Impact on Safety?

Motorway Three

Today the state of Maine raised its speed limit from 65 to 75 mph. Across the Atlantic, today it was also announced that the British government wants to raise the speed limit to 80 mph. Proponents argue that increasing the speed limit will propmote economic growth through reducing congestion, which was touched upon in the TTI report "Speed Harmonization and Peak-period Shoulder Use to Manage Urban Freeway Congestion." Opponents are concerned about the implications on traffic safety. Purdue's Fred Mannering wrote about the relationship between safet and speed in his 2009 article, "An empirical analysis of driver perceptions of the relationship between speed limits and safety." In the report, "Long-Term Speed Compliance and Safety Impacts of Rational Speed Limits," researchers from University of Virginia and VTRC found that increased speed limits along with coordinated education and enforcement can be safe.

 

Friday Seminar - Paul Waddell on Pedestrian Scale in Transportation Models

pedestrian crossing

This week's TRANSOC Friday Seminar feature Paul Waddell from the Department of City & Regional Planning at Cal. He will be present, "Addressing the Challenge of Representing the Pedestrian Sclae in Transportation Models". 

Transportation models have used zonal geography and coarse representations of the transport network to represent the spatial environment for trip origins, destinations and routes.  But the coarseness of the zonal geography and transport networks is inconsistent with the level of detail needed to represent walking and bicycling adequately.  This also has implications for the representation of transit, which is so dependent on walk access at origin and destination of transit trips.  This talk addresses recent work underway as part of projects funded by NSF and MTC, to develop an analytic and visualization capability at a level of detail of parcels and local streets.  Preliminary development of an integrated database, model system, and visualization platform yields early insight into strategies to more fully represent pedestrians and bicyclists within land use and transportation models and planning.

The seminar will be on September 30th, from 4-5 pm in 406 Davis Hall. Cookie Hour preceeding, as usual, in the library at 3:30 pm. See you there!

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