Volvo Center

Accessible Cities and Regions: A Framework for Sustainable Transport and Urbanism in the 21st Century

Cervero, Robert
2005

This paper examines both the principle and analytical possibilities of accessibility as a platform for advancing sustainable transport and urbanism in coming years and decades. Experiences with accessibility planning are first reviewed, followed by a discussion of various measurement and analytical contexts. The paper then uses various policy contexts and case settings to probe the use of accessibility for addressing contemporary urban and regional transportation and land-use themes, including: inter-modal comparisons of job accessibility and their implications for social equity and...

Toward Green TODs

Ververo, Robert
Sullivan, Cathleen
2010

Green Transit Oriented Developments (TODs) shrink environmental footprints by reducing Vehicle Kilometers Traveled (VKT)/ Vehicle Miles Travled (VMT) and incorporating green urbanism and architecture in community designs. Synergies from combining TOD and green urbanism derive from increased densities, which promote transit usage and conserve heating/cooling expenses; mixed land uses which promote non-motorized transportation and limited-range electric vehicles; reduced impervious parking services matched by increased open space and community gardens; and, opportunities for generating solar...

A congestion mechanism for uphill expressways, Part I: the shoulder lane "release valve"

Patire, Anthony D.
Cassidy, Michael J.
2010

A mechanism is unveiled by which congestion forms and persists near the base of an uphill expressway segment, causing significant reductions in output flow. The traffic condition in the expressway's shoulder lane is key to the mechanism. When shoulder-lane flow was low, drivers maneuvered around speed disturbances that periodically arose in the median lane. The shoulder lane accommodated high rates of vehicle migrations, thus acting as a "release valve" for the excess accumulation created by the speed disturbances. The release valve failed only when demand increased later in the rush. The...

Unintended Impacts of Increased Truck Loads on Pavement Supply-chain Emissions

Sathaye, Nakul
Horvath, Arpad
Madanat, Samer M.
2009

In recent years, the reduction of freight truck trips has been a common policy goal. To this end, policies aimed at influencing load consolidation, load factors and increasing maximum truck weight limits have been suggested and implemented, resulting in higher gross vehicle weights. The purpose of such policies has generally been to mitigate congestion and environmental impacts. However, trucks cause most of the damage incurred by highways pavements. The supply chain associated with pavement maintenance and construction releases significant air emissions, raising the question of whether...

China's Urban Transportation System: Issues and Policies Facing Cities

Cherry, Chris
2005

China is the most populous country in the world. With a population of 1.3 billion, meeting the housing and transportation needs of this vast country are on the forefront of the political and academic agenda in China and throughout the world. China has experienced phenomenal economic and social growth and as a result the Chinese have desired more mobility and living space. The effects of these desires are beginning to be seen in new auto oriented ex-urban developments that have larger living spaces than the traditional urban centers and whose road infrastructure is developed to support high...

Structure of Competitive Transit Networks

Daganzo, Carlos F.
2009

This paper describes the network shapes and operating characteristics that allow a transit system to deliver a level of service competitive with that of the automobile. To provide exhaustive results for service regions of different sizes and demographics, the paper idealizes these regions as squares, and their possible networks with a broad and realistic family that combines the grid and the hub-and-spoke concepts. The paper also shows how to use these results to generate master plans for transit systems of real cities.The analysis reveals which network structure and technology (Bus, BRT...

Evaluation of Traffic Data Obtained via GPS-Enabled Mobile Phones: the Mobile Century Field Experiment

Herrera, Juan C.
Work, Daniel B.
Herring, Ryan
Ban, Xuegang (Jeff)
Bayen, Alexander M.
2009

The growing need of the driving public for accurate traffic information has spurred the deployment of large scale dedicated monitoring infrastructure systems, which mainly consist in the use of inductive loop detectors and video cameras. On-board electronic devices have been proposed as an alternative traffic sensing infrastructure, as they usually provide a cost-effective way to collect traffic data, leveraging existing communication infrastructure such as the cellular phone network. A traffic monitoring system based on GPS-enabled smartphones exploits the extensive coverage provided by...

Innovative Bus-Lane Deployments in Amman: Proposed Field Experiments

Guler, Ilgin
Cassidy, Michael
2010

Innovative strategies for deploying bus lanes are proposed for field tests in Amman, Jordan. The objective is to reduce delays to buses in the network while minimizing delays to other vehicular traffic. The proposed strategies may be far better options than conventional, static bus lanes, given the test site’s large car demand and low bus frequency. The experiment is designed to be conducted in simple, safe ways, without the need for investment in permanent infrastructure.

A Dynamic Holding Strategy to Improve Bus ScheduleReliability and Commercial Speed

Xuan, Yiguang
Argote, Juan
Daganzo, Carlos F.
2011

Bus systems are naturally unstable. Without control, the slightest disturbance to bus motion can cause buses to bunch, reducing schedule reliability. Holding strategies can eliminate this instability. However, the conventional schedule-based holding method requires too much slack time, which slows buses. This delays on-board passengers and increases operating costs. This paper studies a family of dynamic holding strategies that use the current state of all buses, as well as a virtual schedule. The virtual schedule is introduced whether the system is run with a published schedule or not. We...

Morning Commute with Competing Modes and DistributedDemand: User Equilibrium, System Optimum, and Pricing

Gonzales, Eric J.
Daganzo, Carlos F.
2011

The morning commute problem for a single bottleneck is extended to model mode choice in an urban area with time-dependent demand. This extension recognizes that street space is shared by cars and public transit. It is assumed that transit is operated independently of traffic conditions, and that when it is operated it consumes a fixed amount of space. As a first step, a single fixed-capacity bottleneck that can serve both cars and transit is studied. Commuters choose which mode to use and when to travel in order to minimize the generalized cost of their own trip. The transit agency chooses...