Electric Vehicles: Coast to coast, but will they impact emissions?

This week was a milestone in electric vehicle adoption and infrastructure in the US - a father-daughter team completed the first crosscountry roadtrip in a Tesla and it cost them $0 to recharge. What a bargain! Tesla Motors plans to expand their recharching network, so that future continental treks may take a more direct route.  

So as electric vehicles are slowly becoming more mainstream, the question is what impact will they have on greenhouse gas emissions? A paper recently presented at the TRB Annual Meeting looks at regional impacts in California.  Another recent study from NC State questions the impact electric vehicles have on emissions at all. Samaneh Babaee, Ajay S. Nagpure, and Joseph F. DeCarolis ask, "How Much Do Electric Drive Vehicles Matter to Future U.S. Emissions?". Their answer: probably not much given the emissions produced by electricity sources.

Modeling Escalator Capacity

Escalators are an under appreciated component of many public transportation systems. Can you imagine using the Dupont Circle Metro station without them? 

A recent paper from the Transportation Research Record examines the role of escalators in public transit systems. "Modeling the Practical Capacity of Escalators: A Behavioral Approach to Pedestrian Simulation" by Peter Kauffmann and Shinya Kikuchi looks at how escalators affect pedestrian behavior and public transit. 

Escalators are an essential mode of public transportation that enable people to travel vertically within a facility at a continuous, high flow rate. Despite the importance of the role of escalators in many facilities, little systematic analysis of the capacity of escalators has been conducted within the field of transportation engineering. A method is presented to calculate the practical capacity of escalators with a simulation based on pedestrian behavioral rules. The capacity of an escalator is defined traditionally only as a function of speed with speed-capacity curves defined by manufacturers or found in empirical studies. These methods do not consider pedestrian behavioral patterns and preferences such as following distance, passing aggressiveness, and other local factors. A rule-based model provides the flexibility to analyze conditions in various public facilities and to answer hypothetical research questions. Three major findings are reported. First, the practical capacity of escalators in commercial facilities such as shopping malls is significantly lower than the maximum capacity in a commuter facility such as a transit station, at only 20% to 40% of what is generally reported by manufacturers to provide for freedom of movement and pedestrian comfort. Second, the model shows that prohibition of walking on escalators can stream-line operations in emergency scenarios because it reduces variability in the system and increases flow, particularly during peak periods. Finally, contrary to some claims in the literature, uphill flow on escalators operates at a lower capacity than does downhill flow because of the presence of a "facial ellipse," the region directly in front of a pedestrian's face.

The full paper can be found online here. 


Library Closed 12/23/13-1/20/14

Snow Day in Seattle

We're closing for the Winter Break from December 23, 2013 to January 20, 2014. We'll reopen on the first day of the Spring Semester - Tuesday, January 21, 2014 at 1:00 PM. Enjoy your time off and see you after the New Year and the TRB Annual Meeting

New from ITDP: The Bike-Share Planning Guide

Divvy Bike Share Station

Last week the Institute for Transportation and Development Policy (ITDP) dropped a new document about bike-share. The Bike-Share Planning Guide provides an overview of bike-share systems internationally and gives best practices. You can download the whole report here.

Who Pays for Parking?

My parking garage

That's the question asked by a new report from the Sightline Institute. "Who Pays for Parking?" analyses 23 recently completed Seattle-area multi-family housing develops. Some of the findings include: 

  • Apartment developers build more parking than is needed.
  • Many tenents don't own cars.
  • Car-free tenants still pay for parking.

The full report can be download here

Uber to expand into "urban logistics"?

Travis Kalanick, Co-Founder & CEO, Uber @ LeWeb Paris Day 1 2013-2555

Transportation Network Company, or as most people refer to them, rideshare company Uber is looking to expand its market. This week Chief Executive Travis Kalanick spoke a Le Web, where he described the Uber's plans to enter "urban logistics". He said, "Today, we are in the business of delivering cars in five minutes. Once you're in the business of delivering cars in five minutes, there are a lot of things you can deliver in five minutes."

Phase 2 will build upon notable promotions as delivering kittens, ice cream, and Christmas trees

Built Environment Impacts on Individual Mode Choice

Downtown Houston

The built environment has an impact on mode choice. It's a topic ripe for study. In "Built Environment Impacts on Individual Mode Choice: An Empirical Study of the Houston-Galveston Metropolitan Area" by Jae-Su Lee, Jin Nam & Sam-Su Lee examines the built environment and mode choice for the city of Houston, publised in the most recent issues of the International Journal of Sustainable Transportation.

This study examines the impacts of the built environment measures based on two geographic scales, i.e., traffic analysis zone and one quarter-mile buffer on individual mode choice in the Houston metropolitan area. It is confirmed that they have significant impacts on mode choice in varying degrees. The models including the buffer-based measures are more reasonable than those with conventional zone-based variables for both home-based work and other trips. Finally, the elasticity estimates suggest the built environments are undervalued in the conventional transportation practices. Both land use and transport pricing measures should be considered complementary to control the demand for driving.

You can read the whole paper here

Friday Seminar: SFpark: A New Approach to Managing Parking

Parking meters...four/five forms of payment

Today's TRANSOC Friday Seminar features Jay Primus talking about SFpark

SFMTA established SFpark to use new technologies and policies to improve parking in San Francisco. SFpark works by collecting and distributing real-time information about where parking is available so drivers can quickly find open spaces. To help achieve the right level of parking availability, SFpark periodically adjusts meter and garage pricing up and down to match demand. Demand-responsive pricing encourages drivers to park in underused areas and garages, reducing demand in overused areas. Through SFpark, real-time data and demand-responsive pricing work together to readjust parking patterns in the City so that parking is easier to find.

This presentation will be an overview of SFpark, a new approach to managing parking that is being demonstrated in San Francisco. We will run through a deep overview of the project’s planning, implementation, and operation, and touch on lessons learned and relevance for other cities.

The seminar takes place from 4:00-5:00 PM in 534 Davis. Cookie Hour commences at 3:30 in the library. See you then!

Closed 11/27-11/29 for Thanksgiving

Wild turkeys on my bike ride in the Oakland hills.

We will be closed Wednesday November 27 through Friday November 29 for the Thanksgiving holiday. Thanksgiving marks the beginning of the holiday season, which means shifts in travel behavior patterns. 

Happy Thanksgiving! See you on Monday, December 2. 

Friday Seminar: Adaptive Optimization Methods in System-Level Bridge Management

Halsted bridge

This week's TRANSOC Friday Seminar features ITS Berkeley PhD candidate Haotian Liu presenting Adaptive Optimization Methods in System-Level Bridge Management.

An adaptive optimization approach, known as Open-Loop Feedback Control (OLFC), is presented for Maintenance, Repair and Replacement planning of systems of bridge components. The proposed implementation of OLFC in Bridge Management Systems is intended to improve bridge management decision-making and deterioration model learning. The OLFC approach is capable of providing more accurate models than the state-of-the-art methods and yielding system cost-savings over any planning horizon when condition survey data are used to update the bridge component deterioration models. OLFC also enables agencies to consider different model classes when learning deterioration models. To illustrate the desirability of this approach, a planning agency is considered to manage a system of facilities with limited prior knowledge of the deterioration models over a designated planning horizon. OLFC is shown to improve model accuracy and reduce system costs, with a demonstration of how to incorporate system budget constraints when the system is heterogeneous. The discussion is confined to bridge decks, the component of bridge structures that undergoes the fastest deterioration, but the methodology presented in this paper is applicable to all bridge components.

The seminar will take place on Friday November 22, 2013 from 4:00-5:00 PM in 534 Davis. Cookie Hour will be taking place as usual in the library at 3:30 PM. 

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