published journal article
conference paper
published journal article
conference paper
The critical link between land use and transportation is human environment relations. Measurement of the environment includes representation of the spatial opportunities available to engage in activities and the infrastructure accessed by trip makers. In this paper an experiment is reported using travel behavior data from the statewide travel survey in California and a variety of activity opportunity measures at two different levels of geographic aggregation that are the tract and the block group levels covering the entire state. Using regression models the authors find these spatial measures to be significant explanatory variables and that measures form both aggregation levels explain behavior capturing a variety of complex influences. This study is also a demonstration that land use indicators and infrastructure availability can be included in travel behavior equations used in the four step and/or activity based forecasting models with largely available data in the Census Transportation Planning Package, network data available in transportation agencies, and typical regression methods included in statistical packages. Next steps are also outlined in the paper.
book/book chapter
conference paper
Daganzo (1997) proposed a kinematic wave model of a traffic system with priority vehicles and special lanes, where the priority vehicles can use both regular and special lanes, but the regular vehicles can only use the regular lanes. Further in Daganzo et al. (1997), the Incremental Transfer (IT) principle was applied to devise a Cell Transmission Model to numerically solve the model. In this paper we first derive the fundamental diagram of a traffic system with priority vehicles and special lanes based on Wardrops user equilibrium principle and then show after transforming the variables that there exist two auxiliary Lighthill-Whitham-Richards model, which can be used to define the demand and supply functions. We present a new junction flux function for the Cell Transmission Model, which is simpler than the IT principle, and more importantly, is a lane-based formulation. Comparing the proposed fluxes with the Godunov (or IT principle) ones analytically, we identify the cases that they are different. Nevertheless, with numerical experiments, we demonstrate that they are consistent in all the cases in the sense that the stationary states of both models are identical. Finally, we show numerical examples that demonstrate the IT principle is not invariant by using a non-triangular fundamental diagram. (C) 2018 The Authors. Published by Elsevier Ltd.
conference paper
published journal article
published journal article
Plug-in hybrid electric vehicles (PHEVs) consume both gasoline and grid electricity. The corresponding temporal energy consumption and emission trends are valuable to investigate in order to fully understand the environmental benefits. The 24-h energy consumption and emission profile depends on different vehicle designs, driving, and charging scenarios. This study assesses the potential energy impact of PHEVs by considering different charging scenarios defined by different charging power levels, locations, and charging time. The region selected for the study is the South Coast Air Basin of California. Driving behaviors are derived from the National Household Travel Survey 2009 (NHTS 2009) and vehicle parameters are based on realistic assumptions consistent with projected vehicle deployments. Results show that the reduction in petroleum consumption is significant compared to standard gasoline vehicles and the ability to operate on electricity alone is crucial to cold start emission reduction. The benefit of higher power charging on petroleum consumption is small. Delayed and average charging are better than immediate charging for home, and non-home charging increases peak grid loads. (C) 2011 Elsevier B.V. All rights reserved.
conference paper
Traffic-related findings from the evaluation of the Interstate 15 (I-15) congestion pricing project are summarized. The project was a 3-year demonstration that allowed single-occupant vehicles (SOVs) to use the existing I-15 high-occupancy-vehicle (HOV) lanes, known as the I-15 express lanes, for a fee. San Diego State University conducted an independent, multielement evaluation of the I-15 pricing project to assess its impacts for both the ExpressPass and FasTrak phases of this demonstration. The primary project goals were (a) to maximize use of the existing I-15 express lanes, (b) to test whether allowing solo drivers to use the express lanes’ excess capacity could help relieve congestion on the I-15 main lanes, (c) to fund new transit and HOV improvements in the I-15 corridor, and (d) to use a market-based approach to set tolls. At the end of 1999, the I-15 pricing project was meeting its primary objectives. There was substantially better utilization of the express lanes. Both ExpressPass and FasTrak were feasible solutions for generating sufficient revenue to fund the new express bus service, called Inland Breeze. Neither ExpressPass nor FasTrak negatively affected carpool volumes on the express lanes; FasTrak was able to redistribute volumes from the middle of the peak to the peak shoulders. Free-flow conditions were maintained at virtually all times. The project’s primary benefit was the reliability of ontime arrival for users. The project was also able to slightly alleviate congestion on the I-15 main lanes. SOV violation rates in the I-15 express lanes remained substantially below the preproject level. Also discussed are the air quality, delay, and park-and-ride impacts of the project.