Electrification of trucking combined with connected technologies promise to cut the cost of freight transportation, reduce its environmental footprint, and make roads safer. If electric trucks are powerful enough to cease behaving as... more
Electrification of trucking combined with connected technologies promise to cut the cost of freight transportation, reduce its environmental footprint, and make roads safer. If electric trucks are powerful enough to cease behaving as moving bottlenecks, they could also increase the capacity of existing roads and reduce the demand for new road infrastructure, a consequence that has so far been understudied. To explore the potential speed changes of replacing conventional heavy-duty drayage trucks with electric and/or connected trucks, we performed microscopic traffic simulations on a network centered on I-710, the country's most important economic artery, between the San Pedro Bay Ports and downtown Los Angeles, in Southern California. In addition to a 2012 baseline, we analyzed twelve scenarios for the year 2035, characterized by three levels of road improvements and four types of heavy-duty port trucks (HDPT). Our results show that 1,000 hp electric/hydrogen trucks (eTs) can be a substitute for additional freeway lanes in busy freight corridors. While conventional HDPTs with CACC would only slightly increase network speeds, replacing conventional HDPTs with eTs and improving selected I-710 ramps should be sufficient to absorb the forecast increases in drayage demand for 2035 without adding a controversial lane to I-710. Our results highlight the importance of accounting for the impacts on speed of new vehicle technologies in infrastructure planning. They also suggest shifting funding from building new capacity to financing 1,000 hp connected electric trucks in freight corridors until the market for these vehicles has matured.
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The construction of a public transit system in a large metropolitan area can relieve congestion, enhance mobility, and improve air quality. In a well-functioning housing market, these benefits will be reflected in housing prices. In this... more
The construction of a public transit system in a large metropolitan area can relieve congestion, enhance mobility, and improve air quality. In a well-functioning housing market, these benefits will be reflected in housing prices. In this paper, the authors analyze transactions of apartments with elevators from 2007 and 2009 in Kaohsiung (Taiwan’s second largest city) to capture the impact of the opening in 2008 of a brand new mass rapid transit (MRT) system. Data includes time on market information (TOM) so the authors combine a two stage least square model with a geographically weighted regression model to tackle the joint determination of price and TOM. Results show that the opening of the MRT had a statistically significant and positive impact on the value of apartments with elevators. Moreover, accounting for TOM has a negligible impact on the results, which suggests that this information may not be necessary to perform hedonic studies of the housing market.
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We analyze the impact of state and local incentives on household ownership of hybrid electric vehicles (HEVs) while accounting for their socio-economic characteristics. Our large dataset combines household data from the 2009 National... more
We analyze the impact of state and local incentives on household ownership of hybrid electric vehicles (HEVs) while accounting for their socio-economic characteristics. Our large dataset combines household data from the 2009 National Household Travel Survey (NHTS) with zip code-level retail gas prices and congestion data from the Texas Transportation Institute, as well as information about state and city incentives. These incentives include unrestricted HOV access, income tax credit, sales tax rebates, and city parking privileges. By contrast, studies published so far focused on just one or two incentives and/or they analyzed only their local impact. We find that unrestricted access to HOV lanes paired with a parking incentive or sales tax rebates/exemptions can effectively promote household ownership of HEVs; by contrast, state income tax credits do not appear to have a statistically significant impact. Moreover, our results indicate that households are more likely to purchase HEVs in areas where gasoline prices are higher, which suggests that increasing gasoline tax could effectively promote HEVs. Understanding the effectiveness of various government policies is important at a time when there is renewed interest in promoting HEVs to address our dependence on foreign oil, air pollution and global warming.
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Environment, Land Use and Urban Policy.: David Banister, Kenneth Button and Peter Nijkamp, editors. (Environmental Analysis and Economic Policy Series, No. 2). Edward Elgar Publishing, Inc., Glensanda House, Montpellier Parade, Cheltenham, Glos GL50 1UA, United Kingdom, 1999. 608 pp. ISBN 1-85898...more
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Research Interests: Environmental Engineering, Civil Engineering, Air Quality, Transport Engineering, Air pollution, and 11 moreEnvironmental Justice, Intelligent Transport System, Urban And Regional Planning, Los Angeles, Emission reduction, Environmental Impact, Truck, Microscopic Traffic Simulation, Southern California, Economic Benefit, and Air Quality Index
We propose a simple framework combining GIS and hedonic pricing to evaluate the impacts of local industrial odors on surrounding residential houses for four Southern California cities. Using GIS, we flag houses located at various... more
We propose a simple framework combining GIS and hedonic pricing to evaluate the impacts of local industrial odors on surrounding residential houses for four Southern California cities. Using GIS, we flag houses located at various distances from car paint-shops and smelly polluters in the EPA's NET database. After accounting for heteroskedasticity through feasible GLS, we find a statistically significant reduction in house prices of up to 3.4%. These results have implications for the local control of industrial odors.
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Diesel heavy-duty drayage trucks (HDDTs) serving the Ports of Los Angeles and Long Beach in Southern California are large contributors to regional air pollution, but cost remains an obstacle to replacing them with zero-emission HDDTs. To... more
Diesel heavy-duty drayage trucks (HDDTs) serving the Ports of Los Angeles and Long Beach in Southern California are large contributors to regional air pollution, but cost remains an obstacle to replacing them with zero-emission HDDTs. To quantify the health and equity impacts of operating diesel HDDTs, we built a microscopic simulation model of a regional freeway network and quantified their emissions of PM2.5 (particulate matter with a diameter < 2.5 μm) and CO2 in 2012 and 2035, before estimating their contribution to selected health outcomes. We found that 483 premature deaths ($5.59 billion) and 15,468 asthma attacks could be attributed to HDDTs in 2012. Regulations and technological advances could shrink these impacts to 106 premature deaths ($1.31 billion) and 2,142 asthma attacks in 2035 (over 2/3 accruing to disadvantaged
communities) despite population growth and a 145 % jump in drayage traffic, but they still justify replacing diesel HDDTs with zero-emission HDDTs by 2035.
communities) despite population growth and a 145 % jump in drayage traffic, but they still justify replacing diesel HDDTs with zero-emission HDDTs by 2035.
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This paper relies on generalized structural equation modeling (SEM) to explore the relationship between land use, gasoline prices, and driving. The authors analyze data from the Southern California subsample of the 2009 National Household... more
This paper relies on generalized structural equation modeling (SEM) to explore the relationship between land use, gasoline prices, and driving. The authors analyze data from the Southern California subsample of the 2009 National Household Travel Survey (NHTS), which has a quasi-experimental nature thanks to large exogenous variations in gasoline prices during the conduct of the NHTS. The authors’ joint models of residential urban form, vehicle efficiency choice, and vehicle use account for residential self-selection and endogeneity of vehicle preferences in order to explain vehicle miles traveled (VMT) for both work and non-work trips. Residential urban form is treated as a latent construct that reflects variables such as population density, land use diversity and distance to employment centers. The authors’ results suggest that in the short run, households drive 0.15% less for non-work trips when gas prices increase by 1%, while work trips are not responsive to gasoline price changes. Moreover, the direct effect of residential urban form on driving is statistically significant for total and non-work VMT, but it has no impact on work trips. The authors also find that owners of more fuel efficient vehicles tend to be more educated, Asian and younger (under 30). Moreover, households in low density neighborhoods are more likely to have a higher income, to be older than 65 and Caucasian. Finally, the results show that accounting for the nature of trips is important for understanding the short term price elasticity of travel.
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Growing concerns about petroleum dependence, greenhouse gas emissions, and traffic congestion make shared-use vehicle programs look increasingly attractive. They offer an alternative to car ownership that yields benefits to their members... more
Growing concerns about petroleum dependence, greenhouse gas emissions, and traffic congestion make shared-use vehicle programs look increasingly attractive. They offer an alternative to car ownership that yields benefits to their members by lowering the cost of transportation and to society at-large by reducing per capita VMT and increasing the use of public transportation. While neighborhood carsharing programs have already received a lot of attention, station car programs, the other type of shared-use vehicle program, largely have not. In the station car approach, shared vehicles are based at public transportation terminals to “extend” the public transportation network. This paper analyzes responses to a survey of the users of UC-Irvine’s ZEV-NET research program, which employs battery electric vehicles and is managed using information technologies. We find that ZEV-NET users participate in the program because they like the flexibility, the ease of use, and the reliability of ZEV-NET vehicles. ZEV-NET commuters are also more concerned about travel stress, cost, and environmental impacts than those who drive alone. By contrast, the latter place greater value in flexibility, reliability, and to a lesser degree, time. Moreover, the demographic characteristics of ZEV-NET users are not statistically different from those of non-users. As ZEV-NET users are not much more concerned about environmental issues than non-users, just advertising the environmental impacts of this program would not be sufficient to grow ZEV-NET; instead, potential cost advantages should be emphasized. These findings should be useful for designing more station car programs that rely on zero-emitting vehicles.
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Author(s): Brown, Austin L.; Fleming, Kelly L.; Lipman, Timothy; Fulton, Lew; Saphores, Jean Daniel; Tal, Gil; Murphy, Colin; Shaheen, Susan; Austin, Bernadette; Garcia Sanchez, Juan Carlos; Martin, Elliot; Miller, Marshall; Hyland,... more
Author(s): Brown, Austin L.; Fleming, Kelly L.; Lipman, Timothy; Fulton, Lew; Saphores, Jean Daniel; Tal, Gil; Murphy, Colin; Shaheen, Susan; Austin, Bernadette; Garcia Sanchez, Juan Carlos; Martin, Elliot; Miller, Marshall; Hyland, Michael; Handy, Susan; Delucchi, Mark A.; Coffee, Daniel; DeShazo, JR | Abstract: The purpose of this study overall is to explore the policy pathways to achieve a zero carbon transportation system in California by 2045. The purpose of this synthesis report is to describe the existing state of knowledge and policy related to energy use and greenhouse gas (GHG) emissions in the transportation sector, especially in California. It is an interim product of the larger study, which will use this report as the baseline and policy context sections. The report comprises four sections. Section 1 provides an overview of the major components of transportation systems and how those components interact. Section 2 explores key underlying concepts in transportation, incl...
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Changeable Message Signs (CMS) provide motorists with real-time traffic information about traffic congestion, incidents, roadwork zones, speed limits ahead, and Amber alerts. Although they require substantial investments, little appears... more
Changeable Message Signs (CMS) provide motorists with real-time traffic information about traffic congestion, incidents, roadwork zones, speed limits ahead, and Amber alerts. Although they require substantial investments, little appears to be known about their effectiveness. The purpose of this paper is to investigate empirically whether CMS reduce the number of secondary incidents. Our unique dataset combines 2008 weather data with geometric information, road work information, and 2008 accident data for a 74 miles stretch of Interstate 5 from the Mexico-US border to Orange County, CA. This freeway, which has 4 to 6 lanes in each direction and a maximum AADT volume of 230,000 vehicles, is equipped with 11 CMS. Our data suggest that secondary crashes represent approximately 5.2 percent of all primary incidents. We estimate a simple logit model to analyze the factors that contribute to secondary incidents. We find mild evidence that CMS reduce secondary crashes; their influence extend...
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Author(s): Reagan, Amelia, PhD; Saphores, Jean-Daniel, PhD | Abstract: The trucking industry serves as the backbone of the nation’s economy. In 2018, approximately 3.5 million truck drivers were delivering over 70% of all freight tonnage... more
Author(s): Reagan, Amelia, PhD; Saphores, Jean-Daniel, PhD | Abstract: The trucking industry serves as the backbone of the nation’s economy. In 2018, approximately 3.5 million truck drivers were delivering over 70% of all freight tonnage in the United States, generating close to $800 billion in gross revenue annually.1 While 3.5 million truck drivers represents a significant number of jobs, it is not enough to satisfy demand. The trucking industry suffers from a chronic shortage of drivers. Nearly 70,000 additional heavy-duty tractor-trailer drivers in the United States were needed at the end of 2018, according to the American Trucking Associations. And COVID-19 has brought new challenges that may amplify or dampen the driver shortage and in turn impact supply chains. For example, what if a small percentage of long-haul truck drivers became ill? Would it cripple the industry? Would it significantly delay the delivery of essential medical supplies and equipment? New research from UC ...
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Printed wiring boards (PWBs), also knownasprintedbreakdown viatypical biological decomposition pathways. If circuit boards, represent theprevailing interconnect technologytheyareincinerated, their combustion releases greenhouse... more
Printed wiring boards (PWBs), also knownasprintedbreakdown viatypical biological decomposition pathways. If circuit boards, represent theprevailing interconnect technologytheyareincinerated, their combustion releases greenhouse forelectronics anda keyopportunity formakingsignificant gases(GHGs),dioxins, andother potentially harmful gases environmental improvements. Materials presently usedinPWBs intotheatmosphere (2).A bio-based, thermosetting resin maynegatively impacthumanhealth andtheenvironment - system replacing epoxyinPWBswouldresult inbothan during manufacturing andelectronic wastedisposal. We propose amoresustainable design basedonrenewable resources. For bicreased biodegradation rateandGHG-neutrality. Further, material selection we considered environmental issues and bio-based resins require significantly lessenergy toproduce industry-standard criteria forcost, performance, andreliability. thanpetroleum-based epoxysystems. Similarly, theinclusion A matrixformulation basedon biological resins and of BFRs in PWBs alsoraisesserious concerns about environmentally-benign additives was optimized using environmental andhumanhealth. ManyBFRsarealready experimental design techniques. Flaxfibers wereimpregnated classified asneurotoxic andcarcinogenic, areknowntocause withtheoptimized matrixformulation basedonindustry- liver andimmunesystem damage, andarebioaccumulative standard coating techniques. Prototype PWB laminates were (3).Steps should therefore betakentoreplace BFRswith manufactured fromthepre-impregnated fibers. Theresultingnon-hazardous alteratives. Transitioning away from PWB design isa viable alternative withpotentially lower fiberglass inPWBswillalsopotentially reduceother environmental impacts andcosts thancurrently usedPWBs. firgla l Bs relltalso soliaste. oven environmental burdenrelated tosolidwaste.Woven Keywords - printed wiring board; bio-based resin; naturalfiberglass, whichisahighly processed formoffused silica, fiber; prepreg; Design ofExperiment requires significant energy toproduce, inaddition toharsh finishing chemicals suchassilanes tomakeitcompatible with I. INTRODUCTION epoxyresin systems. Replacing fiberglass withnatural fibers Theincreasing global popularity ofelectronic products wouldreduce energycost, GHGs, andeliminate theneedfor hasresulted inanincrease intheconsumption ofmaterials and finishing chemicals. energ required fortheir. production,use,anddisl. Worldwide production ofPWBs seta record high of energyrequired fortheir production, use,anddisposal. $3 3 .ilon20 4,wih eurda siae . Traditional environmental design forelectronics hasfocusedire n onrecycling orreuse.Thishasproven tobeaneffective billion square feet oflaminate and2.5billion square feet of methodforsimpler components suchas casings, but prepreg (afabric pre-impregnated with athermosetting resin improving complex hardware suchasprinted wiring boardsmatrix). Thisincreasing volumeemphasizes theneedfor (PWBs) has been more challenging.Instead, PVv'Bs are either moresustainable materials andcomponent design. Theuseof (PBshabeemorchlenig Inta,PBsaeete abio-based, thermosettingresin systemwith non-halogenated incinerated toreclaim valuable metals, orlandfilled, resulting a retarda, impretgnaedin s wovenaturalfers tee in ~~ ~~ ~ . bohcssi'niomna olto. APV'Bsaea flameretardants, impregnated onwovennatural fibers meets inbthasesin nvionmetalpolltio.
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Freight movement is critical to prosperity, but it also generates substantial external costs such as additional congestion and air pollution. One possibility to mitigate congestion and air pollution from urban freight is to shift freight... more
Freight movement is critical to prosperity, but it also generates substantial external costs such as additional congestion and air pollution. One possibility to mitigate congestion and air pollution from urban freight is to shift freight deliveries to off-peak hours but the environmental benefits of this approach are still uncertain. The purpose of this paper is to start filling this gap by analyzing the impacts on the emissions of selected air pollutants of the PierPASS program, which was implemented in 2005 for drayage trucks serving the San Pedro Bay Ports (SPBP, ports of Los Angeles and Long Beach). The analysis combined TransModeler (a microscopic traffic simulation software) with Motor Vehicle Emissions Simulator (MOVES) to simulate traffic for 24 hours on freeways and arterials in the study area, which extends from the SPBP complex to downtown Los Angeles. Overall, it was found that PierPASS had little impact on congestion in the study area and likely resulted in a small decrease in the emissions of various air pollutants, ranging from -0.1% for carbon monoxide (CO) to -2.3% for particulate matter (PM10). At the same time, while the emissions of air pollutants decreased by approximately 10% for NOx and PM during peak time, they increased by approximately 28% for these same pollutants during off-peak hours compared to pre PierPASS levels. Additional analyses are needed to assess the health impacts of these changes for local residents.
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Origin-Destination (OD) demand estimation is often the most time consuming part of data preparation for simulating real-world networks. This paper presents a new scheme to incrementally augment an existing network when the simulation area... more
Origin-Destination (OD) demand estimation is often the most time consuming part of data preparation for simulating real-world networks. This paper presents a new scheme to incrementally augment an existing network when the simulation area has to be expanded without having to repeat the OD estimation process from scratch. The proposed scheme does not substantially change the demand inputs into the existing portion of the network while the demand tables are estimated for calibration of the newly added areas, thus speeding up the preparation of the simulation model. The authors illustrate their approach on a large network constructed to model traffic between the combined Ports of Los Angeles and Long Beach and downtown Los Angeles.
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Urban tree planting programs have been gaining popularity in the United States. Urban trees have been associated with a variety of environmental benefits, including improvements in air quality, mitigation of urban heat island effects,... more
Urban tree planting programs have been gaining popularity in the United States. Urban trees have been associated with a variety of environmental benefits, including improvements in air quality, mitigation of urban heat island effects, reductions in stormwater runoff, and more recently, carbon sequestration. There are also other potential aesthetic and economic benefits of urban forests, which have been shown to
Research Interests: Environmental Science, Air Quality, Carbon Sequestration, Los Angeles, Global change, and 15 moreFossil Fuels, Air Conditioning, Greenhouse Gas Emissions, Land cover change, Greenhouse Gas, Decision making process, Energy Use, Greenhouse gases, Air Temperature, Arid, Low Income, Economic Benefit, Environmental benefit, Ecosystem processes, and Canopy cover
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The objective of this study is to understand the timing of truck and car accidents in a busy freight corridor (I-110 and I-710 freeways) that connects the Ports of Los Angeles and Long Beach to nearby intermodal rail and trans-loading... more
The objective of this study is to understand the timing of truck and car accidents in a busy freight corridor (I-110 and I-710 freeways) that connects the Ports of Los Angeles and Long Beach to nearby intermodal rail and trans-loading facilities, and various warehouses. The authors analyze 16,417 accidents that occurred between 2005 and 2007 on these two freeways in Los Angeles County, California; approximately 14.5 percent of these accidents involved trucks. Vehicle Miles Traveled (VMT) data were collected from the Freeway Performance Measurement System (PeMS) to compute hourly and monthly car and truck accident rates for both freeways in both traffic directions. Kolmogorov-Smirnov and Cramer–von Mises goodness of fit tests were then calculated to test whether directional accident probabilities are similar or not and whether the risk of an accident is time dependent. The authors found that the probability of an accident involving only cars is highest after midnight (the peak probability occurs between 1 AM and 3 AM for both freeways) while the probability of an accident involving a truck is highest during mid-day (the peak probability occurs between 8 AM and 4 PM for both freeways). These results have implications for programs that attempt to move truck deliveries during off-peak hours such as the PierPass program implemented by the Ports of Los Angeles and Long Beach..
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This paper analyses some environmental and health impacts from the PierPASS program, which shifted drayage trucks operations from daytime/peak hours to evening/night hours to reduce congestion and air pollution at the San Pedro Bay Ports... more
This paper analyses some environmental and health impacts from the PierPASS program, which shifted drayage trucks operations from daytime/peak hours to evening/night hours to reduce congestion and air pollution at the San Pedro Bay Ports (i.e. the Ports of Los Angeles and Long Beach in Southern California). The authors focus on emissions of nitrogen dioxide (NO2) and particulate matter (PM2.5), and some related health impacts, using a framework that integrates microscopic traffic simulation with emission estimation, air dispersion, and a health impact assessment. The authors find that PierPASS had little impact on traffic congestion and slightly decreased overall emissions of NO2 and PM2.5. However, PierPASS substantially changed their day-night distributions: at night, total port truck emissions increased by 19.4% for NO2 and by 19.5% for PM2.5, while daytime emissions decreased respectively by 5.0% and 4.9%. As a result, PierPASS increased air pollutant concentrations during both daytime and nighttime because of atmospheric boundary layer effects. Finally, health impact analyses using the Environmental Protection Agency's (EPA’s) BenMAP model show that the implementation of PierPASS increased annual health costs in the study area (which does not include the ports themselves) by over $430 million.