working paper

Clean on Paper, Dirty on the Road: Troubles with California's Smog Check

Publication Date

October 30, 1995

Associated Project

Author(s)

Amihai Glazer, Daniel B. Klein, Charles Lave

Abstract

Reducing emissions of pollutants from cars requires that new vehicles be designed and built to pollute less, and also requires some ongoing inspection and maintenance programme to ensure that a vehicle’s operation conforms to those design standards. This paper focuses on these programmes, commonly called Smog Check programmes. The most extensive and well-studied Smog Check programme in the United States is in California. Though that state is not typical in all respects, examining its experience is instructive.

Suggested Citation
Amihai Glazer, Daniel B. Klein and Charles Lave (1995) Clean on Paper, Dirty on the Road: Troubles with California's Smog Check. Working Paper Reprint No. 275. Institute of Transportation Studies, UC Irvine: University of California Transportation Center. Available at: https://escholarship.org/uc/item/5514s0hg.

conference paper

Response of light-duty vehicle travel and fuel consumption to fuel costs

Proceedings of the kuhmo-nectar conference on transport economics, valencia, spain

Publication Date

July 1, 2020
Suggested Citation
D. Brownstone and Kent Hymel (2020) “Response of light-duty vehicle travel and fuel consumption to fuel costs”, in Proceedings of the kuhmo-nectar conference on transport economics, valencia, spain.

Phd Dissertation

Assessment of Constant Volume Sampler Based Test Procedure and Charging Scenarios Based Energy Impact of Plug-in Hybrid Electric Vehicles

Publication Date

June 30, 2014

Author(s)

Abstract

The advent of plug-in hybrid electric vehicles (PHEVs) introduces a new vehicle paradigm that consumes both gasoline and electricity. The new concept presents new questions. In particular, (1) what modifications need to be made for test procedures in terms of the emissions and fuel economy measurements for individual vehicles, and (2) what methodology needs to be established to evaluate the energy and emission impacts of a PHEV fleet? For the test procedure, the emission testing has been done by using the continuous sampling method for continuous diluents, the smooth approach orifice (SAO) measurement for ambient air flow, and fuel flow meter (FFM) measurement for fuel consumption in addition to the industry standard constant volume sampler (CVS) system, which faces challenges for PHEVs. Results show that the current CVS dilution factor (DF) exhibits an error resulting in higher emission mass calculation; an alternative procedure can be proposed for the charge depleting cycle to eliminate the overdilution; the CVS system has an error resulting from exhaust left in the tailpipe and CVS sampling line. For the evaluation of the energy impact of PHEVs, the South Coast Air Basin of California (SoCAB) was selected as an example by considering different charging scenarios consisting of different charging powers, locations and time. Results show that petroleum reduction is significant; the all-electric ability is crucial to cold start emission reduction; the benefit of higher power charging is small; delayed and average charging are better than immediate charging for home; and non-home charging increases peak grid load.

Suggested Citation
LI ZHANG (2014) Assessment of Constant Volume Sampler Based Test Procedure and Charging Scenarios Based Energy Impact of Plug-in Hybrid Electric Vehicles. PhD Dissertation. UC Irvine. Available at: https://uci.primo.exlibrisgroup.com/permalink/01CDL_IRV_INST/17uq3m8/alma991012357009704701.

published journal article

Reduction of assaultive behavior following anger treatment of forensic hospital patients with intellectual disabilities

Behaviour Research and Therapy

Publication Date

February 1, 2015

Author(s)

Raymond Novaco, John L. Taylor
Suggested Citation
Raymond W. Novaco and John L. Taylor (2015) “Reduction of assaultive behavior following anger treatment of forensic hospital patients with intellectual disabilities”, Behaviour Research and Therapy, 65, pp. 52–59. Available at: 10.1016/j.brat.2014.12.001.

research report

CARMEN Project 5: Resilience and Validation of GNSS PNT Solutions

Publication Date

November 20, 2023

Author(s)

Todd Humphreys, Qi Alfred Chen, Umit Ozguner, Charles Toth

Areas of Expertise

Suggested Citation
Todd Humphreys, Qi Alfred Chen, Umit Ozguner and Charles Toth (2023) CARMEN Project 5: Resilience and Validation of GNSS PNT Solutions. Final Report. CARMEN UTC. Available at: https://zenodo.org/doi/10.5281/zenodo.10246488 (Accessed: October 10, 2025).

published journal article

Optimal energy taxation in cities

Journal of the Association of Environmental and Resource Economists

Publication Date

April 1, 2018

Author(s)

Rainald Borck, Jan Brueckner

Abstract

This paper presents the first investigation of the effects of optimal energy taxation in an urban spatial setting, where emissions are produced both by residences and commuting. When levying an optimal direct tax on energy or carbon use is not feasible, the analysis shows that exactly the same adjustments in resource allocation can be generated by the combination of a land tax, a housing tax, and a commuting tax. We then analyze the effects of these taxes on urban spatial structure, showing that they reduce the extent of commuting and the level of housing consumption while increasing building heights, generating a more-compact city with a lower level of emissions per capita.

Suggested Citation
Rainald Borck and Jan K. Brueckner (2018) “Optimal energy taxation in cities”, Journal of the Association of Environmental and Resource Economists, 5(2), pp. 481–516. Available at: 10.1086/695614.

conference paper

Take-Off and Landing Weight Estimation From ADS-B Airspeed Profiles

AIAA AVIATION FORUM AND ASCEND 2025

Publication Date

July 16, 2025

Author(s)

Marek Homola, Melissa Lepe, Marek Trávník, Jacqueline (Jacquie) Huynh, R. John Hansman

Abstract

Accurate estimation of aircraft takeoff weight (TOW) and landing weight (LW) is critical for assessing fuel consumption, emissions, noise impacts, and other analyses, yet these parameters are typically unavailable in surveillance data such as Automatic Dependent Surveillance-Broadcast (ADS-B). This study presents a method for estimating aircraft takeoff and landing weights using stabilized airspeed segments from ADS-B surveillance data. The approach is derived by relating lift, weight, and airspeed during stabilized flight phases. The method outlined is validated using one year of operations at Seattle-Tacoma International Airport, analyzing over 10,000 flights across three narrow-body aircraft types: B737-800, B737-900, and A320. Weight estimated from ADS-B airspeed profiles was matched to weight records provided by an airline, achieving mean absolute errors of 5.0–7.4% of maximum takeoff weight (MTOW) for departures and 6.0–7.0% of MTOW for arrivals. The method exhibits minimal systematic bias, with absolute distribution mean errors below 0.4% MTOW in magnitude. The demonstrated accuracy enables applications such as fleet-wide fuel consumption modeling, emissions inventories, and aircraft noise impact assessments, providing a valuable tool for data-driven modeling of aviation operations using existing surveillance infrastructure.

Suggested Citation
Marek Homola, Melissa Lepe, Marek Trávník, Jacqueline L. Huynh and R. John Hansman (2025) “Take-Off and Landing Weight Estimation From ADS-B Airspeed Profiles”, in AIAA AVIATION FORUM AND ASCEND 2025. American Institute of Aeronautics and Astronautics. Available at: https://arc.aiaa.org/doi/abs/10.2514/6.2025-3309 (Accessed: August 21, 2025).

published journal article

What Is the Connection? Understanding Shared Micromobility Links to Rail Public Transit Systems in Major California Cities

Sustainability

Publication Date

January 9, 2024

Author(s)

Mengying Ju, Elliot Martin, Susan Shaheen

Abstract

As shared micromobility (bikes and scooters) has proliferated throughout urban areas, there has been growing interest in how it facilitates connections with rail transit systems. This study explores the magnitude of interactions between shared micromobility and rail public transit systems using shared micromobility trip data and rail transit schedule data. We evaluate over one million trips from October 2019 to February 2020 in four California cities (San Francisco, Los Angeles, Sacramento, and San Jose) and develop criteria to identify trips connecting to rail transit. These include spatial and temporal rules, such as whether a trip starts/terminates close to public transit stations and whether a trip takes place when transit systems are operating. The criteria are examined via sensitivity analyses. The results indicate the degree of interaction between rail public transit and shared micromobility varies across cities and systems (i.e., docked/dockless). Most connections take place in the downtown or around public transit hubs. About 5–20% of all shared micromobility trips are identified as accessing or egressing from rail transit. These connecting trips exhibit commute-driven patterns and greater measured velocities. We conclude by examining the applicability of incorporating schedule information into the identification process of shared micromobility trips connecting to rail transit systems.

Suggested Citation
Mengying Ju, Elliot Martin and Susan Shaheen (2024) “What Is the Connection? Understanding Shared Micromobility Links to Rail Public Transit Systems in Major California Cities”, Sustainability, 16(2), p. 555. Available at: 10.3390/su16020555.

Phd Dissertation

Essays in urban economics

Publication Date

January 1, 2009

Author(s)

Abstract

Three independent research papers, all broadly focused on urban and transportation economics comprise the chapters of this dissertation. These empirical papers address a variety of policy oriented issues surrounding the automobile. Although related in theme, the objective, scope, and empirical strategy of each paper differs. The first chapter, “Does traffic congestion reduce employment growth?”, examines the impact of traffic congestion on employment growth in large U.S. metropolitan areas. I use an historic highway plan and political variables to serve as instruments for endogenous congestion. The results show that high initial levels of congestion dampen subsequent employment growth. This finding suggests that increasing the efficiency of public infrastructure can spur local economies. A set of counterfactual estimates show that the employment-growth returns from modest capacity expansion or congestion pricing are substantial. The second chapter, “Induced demand and rebound effects in road transport” (with Kenneth Small and Kurt Van Dender) uses a simultaneous equations model and aggregate data to estimate how drivers’ respond to exogenous increases in vehicle fuel-efficiency. One consequence of efficiency improvements is an increase vehicle use, which can moderate fuel savings. Accurate measures of this so-called ‘rebound effect’, are of interest to policy makers assessing the effectiveness of the Corporate Average Fuel Economy standards. This research paper also measures how traffic congestion and highway infrastructure affect vehicle use. The third chapter, “Evaluating the effectiveness of metered parking policy: evidence from a quasi-experiment”, uses a unique observational data set to assess metered parking policy. Although metered parking is ubiquitous, we know little about its effectiveness, particularly its impact on the retailers it is designed to assist. Sharp twice-daily changes in parking meter enforcement allow me to compare shopping behavior in both free and metered parking environments. Using the regression discontinuity design, I find that parking fees can have large impacts on nearby commerce.

Suggested Citation
Kent Matthew Hymel (2009) Essays in urban economics. Ph.D.. University of California, Irvine. Available at: https://uci.primo.exlibrisgroup.com/permalink/01CDL_IRV_INST/17uq3m8/alma991027750239704701 (Accessed: October 14, 2023).

presentation

Complete Street Composition - Infrastructural Improvements to Transportation Planning and Design in Orange County, California

Suggested Citation
Joseph Faria-Poynter (2022) “Complete Street Composition - Infrastructural Improvements to Transportation Planning and Design in Orange County, California”. 2022 ITS-Irvine Emerging Scholars Transportation Research Showcase, ITS-Irvine, 28 October. Available at: https://youtu.be/Rpdf6-T_fCk?t=1942.