Roads/Highways

Capacity Analysis of Traffic Flow Over a Single-Lane Automated Highway System⋆

Michael, James B
Godbole, Datta N
Lygeros, John
Sengupta, Raja
1998

We calculate bounds on per-lane Automated Highway System (AHS) capacity as a function of vehicle capabilities and control system information structure. We assume that the AHS lane is dedicated for use by fully automated vehicles. Capacity is constrained by the minimum inter-vehicle separation necessary for safe operation. A methodology for deriving the safe minimum inter-vehicle separation for a particular safety criterion is presented. The inter-vehicle separation, which depends on the vehicle braking capability, control loop delays and operating speed, is then used to compute site-...

Do Public Transport Improvements Increase Agglomeration Economies? A Review of Literature and an Agenda for Research

Chatman, Daniel G.
Noland, Robert B.
2011

Public transport improvements may increase economic productivity if they enable the growth and densification of cities, downtowns, or industrial clusters and thereby increase external agglomeration economies. It has been argued that the potential agglomeration benefits are large; if so, understanding them better would be useful in making funding decisions about public transport improvements. We reviewed theoretical and empirical literature on agglomeration as well as a small number of articles on transportation's role in agglomeration. The theoretical literature is useful in understanding...

A Method for Design and Specification of Longitudinal Controllers for Vehicle Automation

Godbole, Datta N.
Sengupta, Raja
1998

Within the context of advanced vehicle control systems, the authors present a general methodology for the design and evaluation of vehicle safety systems. The safety of a vehicle automation system is characterized by the operating region and capabilities of the controller, and the disturbance generating capabilities of the traffic and roadway. The authors illustrate the methodology with reference to a vehicle following scenario. Different information structures are compared by analyzing their effect on safety and system capacity

A New Method for the Direct Measurement of Parking Incentive Response Curve

Tang, Dounan
Sengupta, Raja
2018

Knowing parking price response curve allows one to set the price right. This response curve is often estimated by observing changes in occupancy concomitant with small changes of price. In the authors' Value Pricing Pilot (VPP) Program study, called FlexPassPlus, the authors have used a new method to measure this quantity. By setting up repeated 2nd price auctions via an app the authors were able to get a lot more information about elasticity than through a traditional change-the-price-and-see-what-happens experiment. This leads to a better understanding of the parking incentive response...

A Systems Approach to Sizing of Co-operative High-Accuracy Location (C-HALO) Services Validated by Experiments in San Francisco

Ekambaram, Venkatesan N.
Manasseh, Christian
Goodliss, Adam
Sengupta, Raja
Ramchandran, Kannan
2011

This paper presents a methodology for assessing the accuracy gap between the current level-of-service provided by the US GPS constellation and DGPS, and the level-of-service envisaged by new Cooperative High-Accuracy LOcation (C-HALO) services that achieve decimeter accuracy. We present a novel GIS-based Hidden-Markov Model (HMM) predictive framework to estimate the fraction of roads with low satellite visibility counts that we call as the “dark area”, where C-HALO cannot be realized. Out of the total area of San Francisco (121 sq.km), 0.3 to 4% of the San Francisco streets are predicted...

An Infrastructure Assisted Concept for Automated Highway Systems

Godbole, D.
Miller, M.
Misener, J.
Sengupta, Rahul
Tsao, J.
1996

An Automated Highway System (AHS) is defined as a vehicle-freeway system that enables hands-off feet-off driving on dedicated lanes. This paper documents an AHS concept, developed by the National AHS Consortium as one of five promising concepts. The concept features vehicle-to-vehicle communication, communication and distributed intelligence between the vehicle and the infrastructure. The concept is tailored to support two different vehicle-following rules, i.e., free-agent and platooning. Vehicle-to-vehicle communication enables higher throughput via smaller average longitudinal spacing...

Application of Design and Evaluation Tools to the Automated Highway System

Misener, J.
Deshpande, A.
Godbole, D.
Sengupta, Rahul
Michael, B.
Broucke, M.
1996

An essential aspect of the Automated Highway System (AHS) program is to provide rigorous analytical and simulation tools to evaluate AHS concepts, then facilitate translating them into a prototype design. To address this challenge, the National Automated Highway System Consortium (NAHSC) has adopted a multi-organizational and multi-disciplinary approach to identify, develop and tailor a suite of computational tools with sufficient modeling fidelity, credibility and clarity to meet the disparate needs of AHS designers, evaluators and stakeholders. Development of the AHS toolbox is tightly...

Breaking the Highway Capacity Barrier: Adaptive Cruise Control-Based Concept

Godbole, Datta N.
Kourjanskaia, Natalia
Sengupta, Raja
Zandonadi, Marco
1999

A single-lane advanced vehicle-highway concept that can increase driving comfort and highway capacity is proposed. The concept can be implemented in the near future as it uses the adaptive cruise control (ACC) technology on vehicles and the intelligent ramp metering technologies on the roadway. A simulation-based performance evaluation of single-lane ACC systems under different traffic conditions is presented. The results indicate that drivers can fully use ACC systems even in stop-and-go-traffic, thereby reducing driving stress. It is also shown that ACC-equipped vehicles can maintain a...

Capacity Analysis of Traffic Flow Over a Single-Lane Automated Highway System

Michael, James B
Godbole, Datta N
Lygeros, John
Sengupta, Raja
1998

We calculate bounds on per-lane Automated Highway System (AHS) capacity as a function of vehicle capabilities and control system information structure. We assume that the AHS lane is dedicated for use by fully automated vehicles. Capacity is constrained by the minimum inter-vehicle separation necessary for safe operation. A methodology for deriving the safe minimum inter-vehicle separation for a particular safety criterion is presented. The inter-vehicle separation, which depends on the vehicle braking capability, control loop delays and operating speed, is then used to compute site-...

Cooperative Collision Warning: Enabling Crash Avoidance with Wireless Technology

Misener, James A.
Sengupta, Raja
Krishnan, Hariharan
2005

In this paper we present an overview of the Cooperative Collision Warning (CCW) project conducted by the University of California Partners for Advanced Transit and Highways (PATH) program and General Motors Research and Development which examined and demonstrated wireless-enabled vehicle-to-vehicle cooperative safety systems for collision warning. We developed and demonstrated three Cooperative Collision Warning safety applications: a forward collision warning assistant, an intersection assistant, along with a blind-spot and lane change “situational awareness” assistant. The combination...