conference paper
published journal article
conference paper
policy brief
Shared micromobility (e.g., e-scooters, bikes, e-bikes) offers moderate-speed, space-efficient, and “carbon-light” mobility, promoting environmental sustainability and healthy travel. While the popularity and use of shared micromobility has grown significantly over the past decade, it represents a small share of total trips in urban areas. To better understand shared micromobility ridership, researchers from across the U.S. and the world have analyzed statistical associations between shared micromobility usage and various explanatory factors, including socio-demographic and -economic attributes, land use and built environment characteristics, surrounding transportation options (e.g., public transit stations), geography (e.g., elevation), and micromobility system characteristics (e.g., station capacity). To understand what these studies collectively mean in terms of expanding shared micromobility usage, we conducted a meta-analysis of 30 empirical studies and then developed robust estimates of factors that encourage ridership across different markets.
published journal article |
Aug 2023
conference paper
Transit agencies are interested in integrating microtransit service with fixed-route transit (FRT) service to leverage the benefits of each mode. In an integrated FRT and microtransit system, fare structures for both FRT and microtransit services play an important role in influencing travelers’ behavior. This paper studies 10 different fare structures and their impacts on travelers’ behavior in the presence of an integrated FRT and microtransit system. We use a flexible agent-based FRT and microtransit modeling framework recently proposed by the authors to study fare structures. We analyze the impacts of fare structures on synthetic travelers in downtown San Diego and Lemon Grove, a small city in San Diego County. The results show that the intermodal transfer discount policy — where a traveler can use FRT freely when transferring from microtransit to FRT or receives a 50% discount on microtransit when transferring from FRT to microtransit — is the most promising. Under this fare structure, the subsidy per transit rider ($8.20 in downtown San Diego and $13.5 in Lemon Grove), transit user out-of-pocket costs ($1.27 in downtown San Diego and $1.71 in Lemon Grove), and auto mode share (80.6% in downtown San Diego and 86.5% in Lemon Grove) are the lowest of any fare structure.
research report
A systematic evaluation of the performance and effectiveness of a Field Operational Test (FOT) of an integrated corridor-level adaptive control system was attempted from fall 1994 through spring 1999 in the City of Irvine, California. The FOT was conducted by a consortium consisting of the California Department of Transportation (Caltrans), the City of Irvine, and two private sector consultants, National Engineering Technologies, Inc. (NET) and Farradyne Systems, Inc. (FSI, now PB/FSI), with the City of Irvine as the lead agency. The FOT was cost-share funded by the Federal Highway Administration as part of the Intelligent Vehicle Highway System Field Operational Test Program. The FOT involves an integrated Advanced Transportation Management System (ATMS) which extends the capabilities of existing traffic management systems in the City of Irvine and in Caltrans District 12 (D12). The evaluation originally entailed both a technical performance assessment and a comprehensive institutional analysis. This documentation of the Irvine Field Operation Test does not constitute a formal evaluation due to the failure of any of the planned technologies to be successfully implemented in the field. Due to the extended time frame associated with the project and the significant range of technical and institutional issues associated with the development and eventual failure of the FOT, a summary of project development, institutional barriers, and technical failures is provided.
published journal article |
Jan 2002
conference paper |
Jan 2002
working paper
The household activity pattern problem of analyzing/predicting the optimal path of household members through time and space as they complete a prescribed agenda of out-of home activities is posed as a variant of the pickup and delivery problem with time windows. The most general case of the model includes provision for vehicle transfer, selective activity participation, and ridesharing options. A series of examples are solved using generic algorithms. The model is purported to remove existing barriers to the operationalization of activity-based approaches in travel behavior analysis.
published journal article
Much of the literature on the economics of mortgage markets has studied the fixed vs. adjustable-rate mortgage choice made by individual borrowers. However, to decide if the outcome of such a choice is efficient or approximately so, it is necessary to explore the question of optimal risk-sharing in mortgage contracts. But because only a small literature has studied this question, more research is clearly warranted. The present article helps fill this gap by developing a simplified version of Arvan and Brueckner’s model, using it to characterize optimal contracts in the absence of mortgage termination, and then exploring how termination via prepayment or default affects optimal risk-sharing. The broad conclusion of the analysis is that potential mortgage termination makes higher risk exposure for borrowers optimal.
Phd Dissertation
Commercial vehicles typically represent a small fraction of vehicular traffic on most roadways. However, their influence on the economy, environment, traffic performance, infrastructure, and safety are much more significant than their diminutive numerical presence suggests. This dissertation describes the development and prototype implementation of a new high-fidelity inductive loop sensor and a ground-breaking commercial vehicle classification system based on the vehicle inductive signatures obtained from this sensor technology. This new sensor technology is relatively easy to install and has the potential to yield reliable and highly detailed vehicle inductive signatures for advanced traffic surveillance applications. The Speed PRofile INterpolation Temporal-Spatial (SPRINTS) transformation model developed in this dissertation improves vehicle signature data quality under adverse traffic conditions where acceleration and deceleration effects can distort inductive vehicle signatures. The axle classification model enables commercial vehicles to be classified accurately by their axle configuration. The body classification models reveal the function and unique impacts of the drive and trailer units of each commercial vehicle. Together, the results reveal the significant potential of this inductive sensor technology in providing a more comprehensive commercial vehicle data profile based on a unique ability to extract both axle configuration information as well as high fidelity undercarriage profiles within a single sensor technology to provide richer insight on commercial vehicle travel statistics.
conference paper |
Jan 2009
research report
published journal article |
Jan 2011