Ant colony routing for Freeways

ants all in it

Do we drive like ants? Researchers from TU Delft's Center for Systems and Control use an ant routing algorithm for freeways. "Ant Colony Routing algorithm for freeway networks" by Zhe Cong, Bart De Schutter and Robert Babuška, explore this topic. 

Dynamic traffic routing refers to the process of (re)directing vehicles at junctions in a traffic network according to the evolving traffic conditions. The traffic management center can determine desired routes for drivers in order to optimize the performance of the traffic network by dynamic traffic routing. However, a traffic network may have thousands of links and nodes, resulting in a large-scale and computationally complex non-linear, non-convex optimization problem. To solve this problem, Ant Colony Optimization (ACO) is chosen as the optimization method in this paper because of its powerful optimization heuristic for combinatorial optimization problems. ACO is implemented online to determine the control signal – i.e., the splitting rates at each node. However, using standard ACO for traffic routing is characterized by four main disadvantages: 1. traffic flows for different origins and destinations cannot be distinguished; 2. all ants may converge to one route, causing congestion; 3. constraints cannot be taken into account; and 4. neither can dynamic link costs. These problems are addressed by adopting a novel ACO algorithm with stench pheromone and with colored ants, called Ant Colony Routing (ACR). Using the stench pheromone, the ACR algorithm can distribute the vehicles over the traffic network with less or no traffic congestion, as well as reduce the number of vehicles near some sensitive zones, such as hospitals and schools. With colored ants, the traffic flows for multiple origins and destinations can be represented. The proposed approach is also implemented in a simulation-based case study in the Walcheren area, the Netherlands, illustrating the effectiveness of the approach.

You can find the full article here

San Francisco Travel Quality Study

14L

A group of ITS Berkeley researchers need your help! The San Francisco Travel Quality Study is looking for participants right now. If you have an Android phone and use SF Muni, sign up!

What is the goal of the study? We want to understand how the quality of public transportation affects people’s choice of how to commute, and how Muni can best be improved to suit riders’ needs. This is an innovative study in which we want to get direct feedback from travelers. We are working with the SFMTA, so their voices will be heard! As a thank you, they receive a free Muni pass for a month!

Who can participate? Anybody who lives and works/goes to school in San Francisco; it doesn’t matter how they currently travel. Currently there is only an Android app available, but if resources permit, we might run an iPhone-based study early next year.

What does participation involve? The first round of the study runs from October 23 until December 7. Participants will be asked to install a survey app on their phones and use Muni on at least five days in November. They will then fill out the mobile mini-surveys (approx. 15 sec. each) for those days, plus three short online surveys (max. 10 min each) over the course of the six weeks of the study.

You can apply here.

Friday Seminar: Schools and Transport Emissions in the Six County Sacramento Region

Mystery Image (1983/232/13,195)

This week's TRANSOC Friday Seminar features Philine Gaffron, a visiting researcher at ITS UC Davis from Hamburg University of Technology. She will present Schools and Transport Emissions in the Six County Sacramento Region.

Environmental justice analyses in the transport field often look at people's exposure to transport emissions at their place of residence. This is both a vital angle as most people spend the majority of their time in and around their homes and it is also a proxy for studying overall exposure since significant amounts of time are spent elsewhere, particularly during the day, when traffic levels are highest. Schools are the most important 'elsewhere' for children and teenagers, who are also among the most vulnerable groups when it comes to the detrimental effects of transport emissions.
She will present the results of her analyses that look at the relationship between emission loads that schools in the Sacramento Area Council of Governments (SACOG) region are experiencing from road traffic and the socio-demographic make-up of their students. These results will further be compared to the findings of other studies investigating health and exposure in the SACOG region. Perhaps the discussion will highlight other work that might yield fruitful comparisons and it would also be interesting to discuss participants' opinions on and experiences with addressing inequalities in this area.

The seminar will take place Friday October 11, 2013 in 534 Davis Hall from 4:00-5:00 PM. Cookie Hour per usual will be in the library at 3:30 PM. 

Wetter Stau: Examining Extreme Weather and Traffic Congestion in Germany.

Wenig Schnee - viel Chaos

Extreme weather events, such as blizzards or heavy rains, cause traffic congestion. A new article in the Journal of Advanced Transportation looks at the relationship in Germany. In "A study of the influence of severe environmental conditions on common traffic congestion features," Hubert Rehborn and Micha Koller use German traffic data to study the relationship on the Autobahn. 

On the basis of real traffic and environmental data measured on German freeways, we studied common features of traffic congestion under the influence of severe weather conditions. We have found that traffic features [J] and [S] defining traffic phases “wide moving jam” (J) and “synchronized flow” (S) in Kerner's three-phase theory are indeed common spatiotemporal traffic features. The quantitative parameters for both traffic phases [S] and [J] were investigated in a comparison of “ideal” weather conditions (good visibility and no precipitation) and severe weather situations (icy road, wind, precipitation, etc.). We showed spatiotemporal congested patterns in several space–time diagrams based on the Automatic Tracking of Moving Jams/Forecasting of Traffic Objects (ASDA/FOTO) model reconstruction for roadside detectors. A statistical study of traffic phase [J] parameters was presented, showing the average values and standard deviation of the quantities. Similarities and differences were analyzed, and some consequences for vehicular applications were discussed to cope with severe weather conditions.

The full article can be found here

Friday Seminar: Autonomous Vehicles

IMG_4915

Tomorrow's TRANSOC Friday Seminar features University of Texas Professor Kara Kockelman presenting, "Autonomous Vehicles: Anticipating Impacts in a World of Increasingly Shared Mobility." 

Autonomous vehicles (AVs) represent a potentially disruptive and beneficial change to the way in which we travel. This new technology will impact roadway safety and congestion, air quality and traveler choices. We estimate the private benefits of each AV (to individual owners) to be on the order of $2,000 per year in the near term, rising to $3,000 eventually, thanks to crash savings, travel time reductions, fuel savings, and parking benefits. When crash savings for others are included, net social benefits are estimated at over $6,000 per AV.

Nevertheless, many barriers to AV implementation and mass-market penetration exist. Initial costs will be too high for most buyers, and U.S. licensing and testing standards are being developed at the state level, rather than under a national framework, which may lead to inconsistencies across states. Liability details remain undefined, security concerns linger, and, absent new privacy standards, a default lack of privacy for personal travel may become the norm. Finally, many impacts, interactions with other components of the transportation system, and implementation details remain uncertain for this new and exciting technology.

This seminar also examines the design and results of an agent-based model for Shared Autonomous Vehicle (SAV) operations, including environmental impacts of a fleet of shared and self-driving vehicles. The model generates trips throughout a grid-based urban area, to mimic realistic travel patterns and departure times. An initial model run estimates the SAV fleet size required to reasonably service all trips, over a 24-hour period. Next, the model is run over 100 days, with driverless vehicles ferrying travelers from one destination to the next. During each 5-minute interval, some unused SAVs relocate to shorten wait times for next-period travelers.

Model applications vary trip generation rates, trip distribution patterns, network congestion levels, service area size, vehicle relocation strategies, and fleet size. Preliminary results indicate that each SAV can replace around eleven conventional vehicles, while adding up to 10% more travel distance than conventional trip-making, resulting in overall beneficial emissions impacts, once fleet-efficiency changes and embodied (versus in-use) emissions are assessed.

The seminar will be from 4-5 PM  in 534 Davis. Cookie Hour will be at 3:30 in the library. 

Book of the Week: The World Beyond The Windshield

 

Anybody who has gone on a roadtrip has experienced changing landscapes and introductions of new locales through the lense of a windshield. The World Beyond The Windshield: Roads and Landscapes in the United States and Europe is a collection of scholarly papers that examine the relaitonship between roads and landscapes. It touches upon aesthetics, concepts of space, and the evolution of road networks. You can borrow our copy or read it online

Friday Seminar: Hybrid Electric Vehicle Energy Management: Harder, Better, Faster, Stronger

2013 Volvo V60 Plug-In Hybrid

This week's TRANSOC Friday Seminar is all about plugin electric hybrid vehicles. UC Berkeley professor Scott Moura will present, "Hybrid Electric Vehicle Energy Management: Harder, Better, Faster, Stronger"

One of the greatest opportunities and challenges in developing a sustainable and efficient transportation infrastructure rests upon intelligent energy management in electrified vehicles. This talk specifically addresses the supervisory control problem in hybrid electric vehicles. That is, how does one optimally split driver power demand among multiple energy sources, e.g. engine and battery? By leveraging electrochemical modeling, optimal control theory, and predictive methods, we demonstrate how to achieve lower fuel costs (better), increased performance (faster), and longer battery lifetime (stronger). Unfortunately, there's no good analogy for "harder". Nevertheless, these results will make you dance.

The seminar takes place from 4-5 PM in 534 Davis Hall. TRANSOC's cookie hour will be in the library as ever at 3:30. 

10 Things You Should Know: Thing 4 - My OskiCat

Our latest installment of 10 Things You Should Know About the ITS Library features a way you can manage all the books you check out... My Oskicat! You can get to My Oskicat through our online catalog OskiCat. You will be prompted to sign on with your Calnet login. Once authenticated you can see an inventory of books you've checked out or placed holds on. You can also renew items online. It's handy. 

CPUC Regulates Network Transportation Companies

big Lyft

Yesterday the California Public Utilities Commission unanimously voted to regulate network transportation companies. This means that companies like Uber, Lyft, and Sidecar will still be able to operate in this state, while they are facing regulatory hurdles in other states (and class-action lawsuits). The San Francisco Cab Driver's Association has responded that the ruling is essentially de-regulation

On Marketplace, Juan Matute from ITS UCLA commented on the decision: “I think this is quite significant... It will be difficult for taxi cab drivers to continue doing exactly what they’ve been doing in the past.”

In the coming months and years, research on the issue will be published. An article in October's issues of the Journal of Transport Geography, "Puncturing automobility?," looks at the effects of carsharing on car ownership. Perhaps there will be similar discussions at the Shared Use Mobility Summit next month, which will cover carshare and bikeshare. Note these transportation network companies are not ridesharing, despite that being the most commonly used term. 

Friday Seminar: Quantifying the Effects of Excessive Fuel Loading at a Major Airline

Waiting

Tomorrow's TRANSOC Friday Seminar is the third of the semester and features our third mode: aviation! This week, UC Berkeley Civil Engineering PhD students (and NEXTOR researchers) Michael Seelhorst and Lu Hao will present. "Quantifying the Effects of Excessive Fuel Loading at a Major Airline"

In the past 10 years, jet fuel prices have risen almost 500%. As a result, fuel now makes up the largest single expense at most airlines. For example, Delta Air Lines spends $12 billion on fuel each year. With more competition from no-frills carriers and less demand from a lagging economy, legacy air carriers have resorted to dramatic cost reduction strategies in recent years.

Airline fuel efficiency has been studied from a variety of perspectives, from increasing fuel efficient technologies to improving aircraft routing. We focus on an area that has been largely ignored: excessive fuel loading. Flight dispatchers often choose to load extra fuel, beyond the mission required amount, to account for flight contingencies, such as long taxi times, air traffic control re-routes, and poor weather conditions. The extra fuel burn required to carry the additional fuel is not trivial, and presents a huge opportunity for airlines to reduce costs. We investigated strategies for reducing fuel consumption at Delta Air Lines through on-site observations and interviews with flight dispatchers as well as statistical analysis of archival fuel loading data. We estimate that $150 million is being wasted every year through unnecessary fueling practices.

The seminar will be from 4:00-5:00 PM in 534 Davis. TRANSOC's Cookie Hour, as ever, will be in the library at 3:30. 

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