Advances in wireless communications have significantly impacted the everyday life of individuals. This has
already had an impact in transportation – simply consider, for example, the proliferation of navigation systems,
and the problem of driver inattention due to the use of wireless devices (as addressed by the new California law
banning the use of cellular phone handsets while driving). A significant challenge to the transportation
engineering community is to harness the capabilities provided by wireless communications to move beyond
traveler “convenience” applications, to create better system operations tools to provide improved mobility. At
a fundamental level, wireless communications provides transportation engineers two critical capabilities that
offer high potential.
1. The ability to collect system status data over links as opposed to points.
2. The ability to exchange data with targeted, mobile vehicles.
This seminar will detail research and findings in three emerging transportation areas supported by wireless
communications: probe-based traffic monitoring, managed lanes, and vehicle infrastructure integration (VII).
Transportation plays a significant role in greenhouse gas emissions, accounting for approximately a third
of the United States’ CO2 inventory. In order to reduce CO2 emissions in the future, transportation policy
makers are looking to make vehicles more efficient and increasing the use of carbon-neutral alternative
fuels. In addition, CO2 emissions can be lowered by improving traffic operations, specifically through the
reduction of traffic congestion. This research examines traffic congestion and its impact on CO2
emissions using detailed energy and emission models and linking them to real-world driving patterns and
traffic conditions. It has been found that CO2 emissions can be reduced through three different strategies:
1) reducing severe congestion, allowing traffic to flow at higher speeds; 2) reducing excessively high
freeflow speeds to more moderate conditions; and 3) eliminating the acceleration/deceleration events
associated with stop-and-go traffic that exists during congested conditions. Details on several CE-CERT
research projects that directly address these strategies will be provided.
The field of engineering systems is the focus of the Engineering Systems Division (ESD), an
interdepartmental unit at MIT. Its mission is as follows:
* Transforming engineering education, research, and practice through the emerging field of engineering systems
* Preparing engineers to think systemically, lead strategically, and address the complex challenges of today’s world, for the benefit of humankind
This talk will focus on the key aspects of this vital and growing field and education initiatives
ESD has undertaken at the undergraduate and graduate levels.
The re-allocation of available roadspace to provide priority for transit is increasing at a rapid rate
worldwide. The case for re-allocation of roadspace to transit is clear where service and passenger volumes
are substantial. However at lower volumes, the need is less clear since the benefits to transit are small but
the impacts on other road traffic large. This work summarizes the major elements of a research project
aimed at defining a balanced framework for roadspace reallocation in relation to transit priority. The
framework aims to clarify the trade-offs required in developing transit priority systems in a range of
traffic circumstances and to provide a balanced allocation of road space based on the full range of impacts.
In particular, the approach focuses on people travel and not vehicle travel. It utilizes advanced traffic
micro-simulation approaches to better understand the on-road operational implications of alternative
transit priority measures and develops a social cost benefit analysis framework to comprehensively value
the benefits and costs of priority measures to transit and traffic travelers. The impacts on general road
congestion and wider environmental, economic and social impacts are considered.
Urban development policies are usefully characterized as either “person-based,” where
directed toward individuals, or “place-based,” where eligibility is conditioned on location.
While extremely popular among local politicians, officials, and community advocates
especially for particularly poor performing neighborhoods there are many well-known
arguments against place-oriented programs. Development aid tied to geography is crudely
targeted and often introduces strong spatial distortions. That said, location contains
information helpful in identifying intended recipients, space constrains individual’s economic
activities, and the effectiveness of people-based programs vary over space. Then there is
the visibility of resources focused on a particular place, a key element of political support.
Geography thus matters as parameter, as externality, as marker, and as political economy,
even as it also introduces distortions: Location introduces both benefits and costs. Rather
than strictly a matter of either/or, the policy question appears to be more one of negotiating
the tradeoffs.
Following recent hikes in the price of gasoline, there has been increasing interest for hybrid cars. Yet, the
recent sales of some hybrid cars (notably the Honda Accord) have been disappointing. This study tries to
analyze Californians’ interest for hybrid cars based on a statewide phone survey conducted in July of
2004 by the Public Policy Institute of California (PPIC). We develop several ordered models to explain
the respondents’ stated interest in hybrid cars. We find that males and respondents with at least some
college education who are concerned about the environment, state a higher interest for hybrid-vehicles.
However, one key reason for considering hybrid cars is the possibility to drive them in carpool lanes,
even with single occupancy. This finding has implications for policies that try to stimulate interest for
hybrid cars.
This is a joint paper with Mana Sangkapichai, a Ph.D. candidate in the Institute of Transportation Studies
at the University of California, Irvine.
The presentation addresses a generic macroscopic model-based approach to real-time freeway network
traffic surveillance as well as a software tool RENAISSANCE that has recently been developed to
implement the approach for field applications. On the basis of stochastic macroscopic freeway network
traffic flow modeling, extended Kalman filtering, and a limited amount of traffic measurements,
RENAISSANCE enables a number of real-time freeway network traffic surveillance tasks, including
traffic state estimation and prediction, travel time estimation and prediction, queue tail/head/length
estimation and prediction (queue tracking), and incident alarms. This presentation introduces the utilized
macroscopic freeway network traffic flow model and a real-time traffic measurement model, upon which
a complete dynamic system model for freeway network traffic is established with special attention to the
handling of some important model parameters. An outline is given of various algorithms and the
functional architecture of RENAISSANCE. Simulation testing results of the major RENAISSACNE
functions are presented with respect to a hypothetical freeway network example. A number of real-data
testing results concerning a 7-km German freeway stretch are presented, focusing on the RENAISSANCE
traffic state estimation function under various circumstances regarding congestion, weather conditions
and traffic incidents. Some recent real-data testing results of the traffic state estimator for a large-scale
freeway network in Southern Italy is also presented. Finally, an outlook of further issues and
RENAISSANCE applications is given.
Since the days of Henry Ford, employers have long argued that higher pay
induces employees to provide additional effort. While the converse is also
thought to be true, there is little empirical evidence testing such a
hypothesis. This void in the literature is due, in large part, to a lack of
available data. Not only are significant company-wide, permanent pay cuts
rarely observed in practice, measures of employee effort are typically
difficult to quantify. This paper examines the effect on effort provided by
U.S commercial airline pilots following large, permanent reductions in pay.
After controlling for other factors known to affect airline on-time
performance, we find evidence that large pay cuts lead to a statistically
significant decline in pilot effort, proxied by an increase in the rate of flight
delays and cancellations. This reduction in pilot effort, however, is typically
short-lived.
The technologies that support intelligent transportation systems (ITS) including sensing,
computing, communications, and advanced algorithms, provide enormous opportunity for
enhancing surface transportation in California, the U.S., and the world. However, the
deployment of these technologies has been slower than some advocates would hope,
mainly because of a number of institutional factors that constrain their adoption and
effective use.
This talk will identify some of the key institutional factors constraining ITS deployment,
and explore how a parallel consideration of the technological opportunities and the
institutional context can enable us to make more progress. The CLIOS Process, as a new
way of thinking about ITS and the strategic alternatives we have before us –both
technological and institutional—will be presented
With wireless communication devices becoming ubiquitous, Advanced Transportation Information Systems based on Inter-Vehicle Communication (IVC) are receiving increasing attention due to their fast response to incidents and resilience to disasters. In such IVC systems, vehicles equipped with wireless devices form a mobile ad hoc network, whose multi-hop connectivity is an important performance measurement. This talk presents an analytical recursive model and a Monte Carlo simulation model for computing the probability for two equipped vehicles or road-side stations to be connected through IVC. These models are derived based on the assumption that inter-vehicle communication is instantaneous with respect to vehicle movement and the concept of Most-Forwarded-within-Range communication chains. The two models, which cross-validate each other, are able to capture the impact of traffic patterns on IVC and yield results consistent with those in literature. Some future research directions will also be discussed.