Transportation Seminar and Cookie Time 9 November: A Macroscopic Approach to Urban Traffic

This week's talk, given by CEE PhD student Nikolas Geroliminis (CV in pdf format), approaches a description of vehicular movement in urban areas on a macroscopic scale. Geroliminis has formed his conclusions using both simulation and real data from metropolitan areas (here is a link to a 4-hour simulation by Geroliminis and Prof. Daganzo). Here is the abstract:

Various theories have been proposed to describe vehicular traffic movement in cities on an aggregate level. They fall short to create a macroscopic model with variable inputs and outputs that could describe a rush hour dynamically. My dissertation work shows that a Macroscopic Fundamental Diagram (MFD) relating production (the product of average flow and network length) and accumulation (the product of average density and network length) exists for neighborhoods of cities in the order of 5-10km2. It also demonstrates that conditional on accumulation large networks behave predictably and independently of their Origin-Destination tables. These results are based on analysis using simulation of large scale city networks and real data from urban metropolitan areas. The real experiment uses a combination of fixed detectors and floating vehicle probes as sensors. The analysis also reveals a fixed relation between the space-mean flows on the whole network and the trip completion rates, which dynamically measure accessibility. This work also demonstrates that the dynamics of the rush hour can be predicted quite accurately without the knowledge of disaggregated data. This MFD is applied to develop perimeter control strategies based on neighborhood accumulation and speeds and improve accessibility without the uncertainty inherent in today’s forecast-based approaches. The looking-for-parking phenomenon that extends the average trip length is also integrated in the dynamics of the rush hour

The seminar will be in 240 Bechtel at 4:00 and will be preceded by Cookie Time in the ITS Library (4th Floor McLaughlin) at 3:30. Please Note: Cookie Time will still be held regardless of other ITS closures for Veterans' Day

Transportation Seminar and Cookie Time 25 October: Smart Parking

Ohh Hello! Please join us in the ITS Library this Friday at 3:30 for our weekly 'Cookie Time.' This week our lecture, beginning at 4:00, is called "Transit-Based Smart Parking in the U.S.: An Evaluation of the San Francisco Bay Area Field Test" and is presented by Dr. Susan Shaheen of UC Berkeley as well as ITS Davis' Transportation Sustainability Research Center (TSRC).

Rising demand for parking at suburban transit stations, such as the Bay Area Rapid Transit (BART) District in California, necessitates strategies to manage traveler demand. To better manage parking supply, researchers implemented a smart parking field test at the Rockridge BART station from 2004 to 2006 to evaluate the effects of smart parking technologies (changeable message signs (CMSs), Internet reservations and billing, mobile phone and personal digital assistant communications, and a wireless parking lot counting system) on transit ridership and response to service pricing. Researchers employed expert interviews, Internet surveys, focus groups, and parking reservation data to conduct this analysis. This presentation provides an overview of the project, behavioral effects of the field test, and lessons learned.

The talk will be held in 240 Bechtel as usual.

Transportation Seminar and Cookie Time 12 October: Newtons and Neural Networks

This weeks talk, upon our 3:30 'Cookie Time,' is presented by PATH researcher Xiao-Yun Lu. The paper has something to do with logit models, mathematics, and neural networks. I'll let the abstract do the talking:

This seminar is to discuss the representability of discrete logit-type models including multinomial logit and nested logit model from a mathematical approach instead of a statistical approach by Prof. D. McFadden. It is shown that the logit-type models can be reconstructed from mathematical approximation theory with sigmoidal functions widely used in Neural Network modeling without the basic assumptions such as IIA and iid, and the distribution (or density) function of the unobserved portion of utility. This explains mathematically why logit-type models can approximate the choice probability function to some accuracy. It is hoped that this may suggest the way to improve the accuracy in model specification for logit type models.

Please come by for some snacks beforehand.

Transportation Seminar and Cookie Time: Freeway Congestion is Not So Good

After this week's Cookie Time, from 3:30 to 4:00 in the ITS Library, the Transportation Seminar will commence in the Bechtel Engineering Center, Room 240. We will be regaled this week with a talk, Freeway Congestion, Ramp Metering, and Tolls, given by Prof. Pravin Varaiya. The abstract-

The Cell Transmission Model of a freeway with multiple origins and destinations is used to compare four schemes to reduce freeway congestion: (R) ramp control only; (T) one lane is tolled and ramps are uncontrolled; (B) bottlenecks are tolled and ramps are uncontrolled; (RB) ramps are controlled and bottlenecks are tolled. In the base case no ramps are metered and there are no tolls. It is found that (T) is inefficient and likely to leave all travelers worse off than in the base case; (R), (B) and (RB) can achieve efficient freeway utilization; (B) can eliminate queues, but has adverse spatial and equity side effects; (RB) minimizes these side effects. (RB) is likely to be much less costly to implement and maintain than (T) or (B).

Prof. Varaiya holds the Nortel Networks Distinguished Professorship in our very own Department of Electrical Engineering and Computer Sciences. Having previously taught also in the Department of Economics and heading the PATH program, he currently studies communication networks, transportation, and hybrid systems. If you miss this talk you will definitely look like a sucker.

Transportation Seminar and Cookie Hour: Big Rigs Gone Automatic

This week's Transportation Seminar features ITS Berkeley alum, Dr. Jacob Tsao, who now teaches at Department of Industrial & Systems Engineering . He'll discuss current research in automated trailer steering. Triple trailer trucks, such as the one shown above, now operate in 20 states in the U.S. Problems with safety and inefficiency due to improper tracking can be reduced or eliminated with automated trailer steering. Improving Safety of Large-Truck Operations with Automated Trailer Steering For Fuel Efficiency,Emission Reduction and Productivity examines the fuel efficiency and sustainability of truck automation.

Energy and environmental concerns have led to much attention on fuel efficiency and sustainable development. A class of large trucks called “longer combination vehicles” (LCVs) currently operates on designated highways in 20 states of the US. Although they provide high fuel efficiency and productivity, they also pose safety and infrastructure hazards. A major source of such hazards is off-tracking – the phenomenon that the rear wheels of a truck do not follow the track of the front wheels. A major category of LCVs is the Triple, consisting of a tractor and three 28-foot trailers, and some Triples also suffer from continuous sideway sway while cruising on the highway. We propose the concept of automated trailer steering to overcome these problems. Vehicle-dynamics models and steering algorithms have been developed. Computer simulation suggests that off-tracking can be virtually eliminated; it also provides a clue for the reason of the continuous sway of some Triples. Systems issues about expanding current LCV operations will be discussed as well as a new mode of freight transportation enabled by automated trailer steering – Short Trailer Combination Vehicles (STCVs).

The Transportation Seminar will be in 240 Bechtel from 4:00-5:00 PM. Cookie Hour precedes the seminar in the ITS Library, 412 McLaughlin Hall, from 3:30-4:00 PM.

Transportation Seminar and Cookie Hour: Going Olympic.

After last week's cookie hour was a resounding success, this week's should prove to be as exciting. Cookie Hour is today in the ITS Library from 3:30-4:00 PM. The Transportation Seminar will then commenceat 4:00 PM in 240 Bechtel. This week's speaker is Professor Philippe Bovy, the IOC Olympic Transport Advisor. He will be giving a talk entitled: Transport and mobility management challenges for the world's largest mega-event: 1992 to 2012 Summer Olympic Games. Here's the abstract:

With about 300 world class events concentrated during 16 Games days but spatially spread over more than 60 competition, training and non-competition venues, the key transport challenge of Summer Olympic Games is to provide safe, convivial and reliable mobility for 1 to 1,5 million daily additional travel journeys. Six distinct client oriented transport schemes must be simultaneously operated 24 hours a day, during all the Games including Opening and Closing Ceremonies. Transport challenges are particularly tough since specific client groups (athletes, sport and media logistics, key VIPs) cannot tolerate any travel uncertainties and delays. Due to Olympic world visibility, the highest possible security protection shall be embedded in all transport operations. Since Sydney 2000 Olympics, policies of 100% spectators by free public transport, of Olympic accredited vehicle movement on a fully dedicated Olympic reserved lane network and of environmentally sustainable traffic management are gradually implemented and optimized. In short, Olympic Summer Games are one of the most unique “transport and advanced mobility management laboratory in the world” and a significant contribution towards more sustainable mobility developments.

The Beijing olympics are a little less than a year away. We here at the ITS Library are more interested in the preparations for the Olympics, than the games themselves. Their new rail lines to the Olympic Village are quite the undertaking. The only thing more interesting about the Olympics are the mascots.
Come on by and say hi.

Transportation Seminar and Cookie Hour: Back with a Vengeance!

Tomorrow is not only the last day of August in 2007, but also the first Transportation Seminar and Cookie Hour for the 2007/2008 academic year.
Cookie Hour will be in the ITS Library (412 McLaughlin Hall) from 3:30-4:00. Library staff will be providing the treats. They may look like this:

(Who doesn't love free, vegan cupcakes? Don't be confused. There will be cookies, too.)
After Cookie Hour the Transportation Seminar will commence from 4:00-5:00 in 240 Bechtel. The speaker will be Adam Meyerson, Ph.D., Assistant Professor, Computer Science Department, University of California, Los Angeles. He will be speaking about Approximation Algorithms for Orienteering and Deadline-TSP.
Come on by and say hello!