Metropolitan size and the impacts of telecommuting on personal travel

Telecommuting has been proposed by policy makers as a strategy to reduce travel and emissions. In studying the metropolitan size impact of telecommuting on personal travel, this paper addresses two questions: (1) whether telecommuting is consistently a substitute or complement to travel across different MSA sizes; and (2) whether the impact of telecommuting is higher in larger MSAs where telecommuting programs and policies have been more widely adopted. Data from the 2001 and 2009 National Household Travel Surveys are used. Through a series of tests that address two possible empirical biases, we find that telecommuting consistently had a complementary effect on one-way commute trips, daily total work trips and daily total non-work trips across different MSA sizes in both 2001 and 2009. The findings suggest that policies that promote telecommuting may indeed increase, rather than decrease, people’s travel demand, regardless of the size of the MSA. This seems to contradict what telecommuting policies are designed for. In addition, model results show that the complementary impact of telecommuting on daily travel is lower in larger MSAs, in terms of both daily total work trips and daily total non-work trips.     

Road transport and climate change: Stepping off the greenhouse gas

Transport is Australia’s third largest and second fastest growing source of greenhouse gas (GHG) emissions. The road transport sector makes up 88% of total transport emissions and the projected emissions increase from 1990 to 2020 is 64%. Achieving prospective emission reduction targets will pose major challenges for the road transport sector. This paper investigates two targets for reducing Australian road transport greenhouse gas emissions, and what they might mean for the sector: emissions in 2020 being 20% below 2000 levels; and emissions in 2050 being 80% below 2000 levels. Six ways in which emissions might be reduced to achieve these targets are considered. The analysis suggests that major behavioural and technological changes will be required to deliver significant emission reductions, with very substantial reductions in vehicle emission intensity being absolutely vital to making major inroads in road transport GHG emissions.     

Analysis of telecommuting behavior and impacts on travel demand and the environment

The discussion of whether, and to what extent, telecommuting can curb congestion in urban areas has spanned more than three decades. This study develops an integrated framework to provide the empirical evidence of the potential impacts of home-based telecommuting on travel behavior, network congestion, and air quality. In the first step, we estimate a telecommuting adoption model using a zero-inflated hierarchical ordered probit model to determine the factors associated with workers’ propensity to adopt telecommuting. Second, we implement the estimated model in the POLARIS activity-based framework to simulate the potential changes in workers’ activity-travel patterns and network congestion. Third, the MOVES mobile source emission simulator and Autonomie vehicle energy simulator are used to estimate the potential changes in vehicular emissions and fuel use in the network as a result of this policy. Different policy adoption scenarios are then tested in the proposed integrated platform. We found that compared to the current baseline situation where almost 12% of workers in Chicago region have flexible working time schedule, in the case when 50% of workers have flexible working time, telecommuting can reduce total daily vehicle miles traveled (VMT) and vehicle hours traveled (VHT) up to 0.69% and 2.09%, respectively. Considering the same comparison settings, this policy has the potential to reduce greenhouse gas and particulate matter emissions by up to 0.71% and 1.14%, respectively. In summary, our results endorse the fact that telecommuting policy has the potential to reduce network congestion and vehicular emissions specifically during rush hours.     

Explaining shipping company participation in voluntary vessel emission reduction programs

Ports are under increasing pressures to increase sustainability and reduce the local and global emissions impacts associated with their operations. Due to limits on their jurisdictional authority, ports may design effective voluntary programs and appropriately motivate participation from global shipping companies that visit their ports. This paper investigates the success of the Vessel Speed Reduction Program at the Ports of Los Angeles and Long Beach and uses qualitative methods to analyze the factors that contributed to the success of the program at reducing local air quality pollutants. In particular, why did individual private firms participate in a non-required, voluntary effort? This research found that external pressures such as community concerns about emissions and regulatory threats are important to motivating voluntary behavior and may even be more important than financial incentives. Furthermore, simplicity of program design, clear goals and presence of a monitoring mechanism are important in influencing participation. These findings broaden our understanding of the business strategy behind slow steaming and its applicability as an operational practice as much work to date is focused on how fuel prices and financial incentives influence the choice for shipping companies to slow their speeds. While the VSR program led to significant emission reductions, an additional lesson for voluntary programs is the need for them to evolve and strive for continuous improvement.     

Sailing into a dilemma: An economic and legal analysis of an EU trading scheme for maritime emissions

On the basis of a joint economic and legal analysis, we evaluate the effects of a “regional” (European) emission trading scheme aiming at reducing emissions of international shipping. The focus lies on the question which share of emissions from maritime transport activities to and from the EU can and should be included in such a system. Our findings suggest that the attempt to implement an EU maritime ETS runs into a dilemma. It is not possible to design a system that achieves emission reductions in a cost efficient manner and is compatible with international law.     

The trade-off between trips and distance traveled in analyzing the emissions impacts of center-based telecommuting

Several travel indicators were compared between telecommuting (TC) days and non-telecommuting days for a sample of 72 center-based telecommuters in California. Distance traveled decreased significantly on TC days, with average reductions of 51 person-miles (58%) and 35 vehicle-miles (53%). When weighted by telecommuting frequency, average reductions of 11.9% in PMT and 11.5% in VMT were found over a five-day work week. Person-trips and vehicle-trips increased slightly (but not significantly) on TC days. This was due to statistically significant increases in commute trips by telecommuters (who more often went home for lunch on their TC days), partly counteracted by decreases in non-commute travel. The drive-alone mode share increased on TC days, both for all trips, and for commute trips in particular. Walking and biking shares also increased modestly on TC days, whereas shares of transit and ridesharing declined. Despite the increase in trip rates, TC-day reductions were found for all pollutants analyzed: 15% for total organic gas emissions, 21% for carbon monoxide, 35% for oxides of nitrogen, and 51% for particulate matter. The reduction in VMT more than compensated for the marginal increase in number of trips (and consequently, cold starts) on telecommuting days.     

Are vehicle emission inspection programs living up to expectations?

To ensure that the advanced emission control systems installed on modern motor vehicles continue to work properly, motor vehicle inspection and maintenance (I/M) programs are now found in the major cities of many countries around the world. These programs are widely regarded as valuable and even essential to the achievement of air quality objectives, but there have been few ex post audits of these programs. In this paper, we examine the performance of one of the most sophisticated I/M programs, the USEPA’s Enhanced I/M Program. This program has now been implemented in five states. Using data from 1995 and 1996, we estimate the cost of the Arizona Enhanced I/M Program and the emission reductions achieved. We begin by enumerating briefly the components of I/M costs and discuss their size and incidence. Then we describe the empirical information from Arizona and how we use it to construct cost estimates for both vehicle inspection and repair of failing vehicles. Inspection costs include the costs of operating the test stations and the costs motorists incur in time and money to get to the station and go through the testing process. We find that the inspection costs account for over two-thirds of the full costs of I/M, while costs associated with actual vehicle repair account for only one-third. We conclude by comparing the empirical estimates of costs and program effectiveness in the Arizona program with the ex ante estimated Enhanced I/M program costs made by the EPA in the 1992 Regulatory Impact Analysis (RIA). The ex ante EPA analysis appears to have underestimated the costs of achieving the ambitious reductions in emissions hoped for under I/M.     

Reducing CO<Subscript>2</Subscript> from cars in the European Union

The European Union (EU) recently adopted CO₂ emissions mandates for new passenger cars, requiring steady reductions to 95 gCO₂/km in 2021. We use a multi-sector computable general equilibrium (CGE) model, which includes a private transportation sector with an empirically-based parameterization of the relationship between income growth and demand for vehicle miles traveled. The model also includes representation of fleet turnover, and opportunities for fuel use and emissions abatement, including representation of electric vehicles. We analyze the impact of the mandates on oil demand, CO₂ emissions, and economic welfare, and compare the results to an emission trading scenario that achieves identical emissions reductions. We find that vehicle emission standards reduce CO₂ emissions from transportation by about 50 MtCO₂ and lower the oil expenditures by about €6 billion, but at a net added cost of €12 billion in 2020. Tightening CO₂ standards further after 2021 would cost the EU economy an additional €24–63 billion in 2025, compared with an emission trading system that achieves the same economy-wide CO₂ reduction. We offer a discussion of the design features for incorporating transport into the emission trading system.     

Challenges and opportunities for transportation: Implementation of the clean air act amendments of 1990 and the intermodal surface transportation efficiency act of 1991

The Federal Clean Air Act Amendments of 1990 (CAAA) may be the most powerful of all environmental laws affecting transportation. They are intended to significantly affect transportation decision-making, not only to achieve air quality goals but also to affect broader environmental goals related to land use, travel mode choice, and reductions in vehicle miles traveled. The CAAA require greater integration of transportation and air quality planning, and assign a greater responsibility to transportation plans and programs for reducing mobile source emissions. By expanding the requirements for determining the conformity of transportation plans, programs, and projects with State Implementation Plans for air quality, and by expanding the use of highway funding sanctions to enforce those requirements, the CAAA ensure a continuing linkage between transportation and environmental goals.While the CAAA give transportation and air quality decision-makers the mandate to better coordinate their respective planning processes, the Intermodal Surface Transportation Efficiency Act of 1991 offers the tools to help carry out that mandate. Consequently, this paper summarizes the transportation and air quality provisions of both of these Acts and their relationships.     

Transportation impacts of center-based telecommuting: Interim findings from the Neighborhood Telecenters Project

The transportation impacts of center-based telecommuting for 24 participants (representing 69 person-days of travel and 295 trips) in the California Neighborhood Telecenters Project are analyzed. Comparing non-telecommuting (NTC) day to telecommuting (TC) day travel shows that person-trips did not change significantly, whereas vehicle-trips increased significantly (by about one trip) on TC days. Both PMT and VMT decline significantly on TC days: by an average of 68 miles (74%) and 38 miles (65%), respectively. When these savings are weighted by the frequency of telecommuting, overall reductions in PMT and VMT come to 19% and 17%, respectively, of total weekday travel. Commute trips increase slightly (by 0.5 trips) but significantly, mainly due to lunch-time trips made home from the telecenter. Total non-commute travel does not increase, but there is a significant shift from other modes to driving alone on TC days. Commute mode split on NTC days is not affected by telecommuting. Travel on TC days tends to be compressed into fewer hours. Higher numbers of return home, eat meal, shopping, and social/recreational trips are made on TC days, in exchange for a reduction (to zero) in the number of change mode trips.     

Estimating emissions reductions from accelerated vehicle retirement programs

Accelerated vehicle retirement programs offer owners of older vehicles incentives to scrap those vehicles earlier than might otherwise occur. Since older vehicles generally pollute more than newer vehicles, public agencies adopt such programs to reduce air pollutant emissions. Current methods of estimating the emissions reduction benefits of the programs are based on several assumptions and limited empirical evidence. This paper uses data from two large-scale programs in California to demonstrate that changing assumptions can significantly alter the assumed benefits of the program. The results show that vehicle retirement programs are likely to reduce emissions, but probably not as much as expected, particularly for nitrogen oxide and carbon monoxide emissions. The differences in estimates stem from several factors: scrapped vehicles are generally driven fewer miles than other vehicles of the same model year; some of the vehicles would have been scrapped without the program or not have lasted as long as expected; emissions for some pollutants may not be as high as predicted; and replacement vehicles are usually older than the fleet average.     

Short trips: An opportunity for reducing mobile-source emissions?

This paper examines how conversion of automobile trips of less than 3 miles to other transportation modes reduces emissions. Short trips contribute disproportionately to emissions because of cold starts. An analysis is conducted of short-trip behavior across the US using the 1995 Nationwide Personal Transportation Survey. The data is used to develop likely scenarios of mode conversions for short trips, which are then applied to estimate emission savings using MOBILE6 cold start and running emission factors for volatile organic compounds, nitrogen oxides, carbon monoxide, and carbon dioxide. The results suggest that reducing short auto trips would modestly reduce mobile source air pollution, but emission reductions are high compared to most federally-funded surface transportation interventions aimed at improving air quality. Enhanced the community pedestrian environment to encourage short trip mode conversion also produces co-benefits such as increased physical activity and subsequent reductions in chronic diseases.     

Does telecommuting reduce vehicle-miles traveled? An aggregate time series analysis for the U.S.

. This study examines the impact of telecommuting on passenger vehicle-miles traveled (VMT) through a multivariate time series analysis of aggregate nationwide data spanning 1966–1999 for all variables except telecommuting, and 1988–1998 for telecommuting. The analysis was conducted in two stages. In the first stage, VMT (1966–1999) was modeled as a function of conventional variables representing economic activity, transportation price, transportation supply and socio-demographics. In the second stage, the residuals of the first stage (1988–1998) were modeled as a function of the number of telecommuters. We also assessed the change in annual VMT per telecommuter as well as VMT per telecommuting occasion, for 1998. The models suggest that telecommuting reduces VMT, with 94% confidence. Together with independent external evidence, the results suggest a reduction in annual VMT on the order of 0.8% or less. Even with impacts that small, when informally compared to similar reductions in VMT due to public transit ridership, telecommuting appears to be far more cost-effective in terms of public sector expenditures.     

Much Ado about Nothing? - An analysis of economic impacts and ecologic effects of the EU-emission trading scheme in the aviation industry

From 2012 on, all CO₂ emissions from flights departing from or arriving at airports within the European Union have to be offset. We analyze the economic and ecological impacts that are caused by an inclusion of the aviation industry into the proposed emissions trading scheme (ETS). Building on the now fixed system design we employ a simulation model to estimate the impacts of the scheme. Our results indicate that financial impacts are highly dependant on external settings, such as allowance prices and demand growth. We show that the financial burden on the aviation industry will be rather modest in the first years after the introduction of the system and therefore induce only low competition distortions. Likewise, emission reductions within air transportation will be comparably low. While aviation will induce a decline of emissions in other sectors, significant absolute reductions within air transportation can only be reached by a more restrictive system design.     

The multi-port berth allocation problem with speed optimization and emission considerations

The container shipping industry faces many interrelated challenges and opportunities, as its role in the global trading system has become increasingly important over the last decades. On the one side, collaboration between port terminals and shipping liners can lead to costs savings and help achieve a sustainable supply chain, and on the other side, the optimization of operations and sailing times leads to reductions in bunker consumption and, thus, to fuel cost and air emissions reductions. To that effect, there is an increasing need to address the integration opportunities and environmental issues related to container shipping through optimization. This paper focuses on the well known Berth Allocation Problem (BAP), an optimization problem assigning berthing times and positions to vessels in container terminals. We introduce a novel mathematical formulation that extends the classical BAP to cover multiple ports in a shipping network under the assumption of strong cooperation between shipping lines and terminals. Speed is optimized on all sailing legs between ports, demonstrating the effect of speed optimization in reducing the total time of the operation, as well as total fuel consumption and emissions. Furthermore, the model implementation shows that an accurate speed discretization can result in far better economic and environmental results.     

Environmental impact of scrapping old cars

Many countries introduced scrapping programs in the 90s, partly legitimated by environmental impact reductions. However, reducing the age of the current car fleet may result in an increase of life-cycle CO₂ emissions. This will probably also be true for cars to be produced in future unless fuel efficiency of new cars improves much faster than the historical trend indicates. Reducing the age of petrol-fuelled cars without a catalytic converter will reduce both life-cycle NO_x and VOC emissions but is less cost-effective than fitting catalytic converters on these cars. In any case, the influence of a car’s lifetime on life-cycle NO_x and VOC emissions will be reduced in the near future.     

Analyzing the preference for non-exclusive forms of telecommuting: Modeling and policy implications

This study examines three models of the individual's preference for home- and center-based telecommuting. Issues concerning the estimation of discrete models when the alternatives are non-exclusive are discussed. Two binary logit models are presented, one on the preference to telecommute from a center versus not telecommuting from a center (adjusted ² = 0.24), and the other on the preference to telecommute from a center over telecommuting from home (adjusted ² = 0.64). A nested logit model is also estimated on the following four alternatives: preferring not to telecommute, preferring either form of telecommuting, preferring to telecommute from home, and preferring to telecommute from a center (adjusted ² = 0.35).The results of the models illustrated the importance of attitudinal measures in measuring an individual's preference to telecommute. Oblique factor scores representing workplace interaction, stress, workaholism, internal control, and commute stress were statistically significant in some or all of the models. Other explanatory variables which were found to be consistently significant were education, job suitability, and age. Most respondents preferred either to telecommute from home or were indifferent between either form of telecommuting, which raises the question as to whether there really is a sizeable market niche to be filled by telecommuting centers, and hence whether they may make a significant contribution to transportation demand reduction.     

Comparing the unit emissions of daily frequency and slow steaming strategies on trunk route deployment in international container shipping

This study examines NO_x, SO₂, CO₂, HC, and PM reductions for international container shipping carriers from slow steaming and from making use of daily frequency strategies. The options are examined using activity-based methods for surveys on Far East-Europe routes. It is found that both strategies examined are effective in reducing emissions, with daily frequency more effective in reducing emission levels when slow steaming is not employed.     

The effects of ozone action day public advisories on train ridership in Chicago

Ground level ozone is a criteria pollutant that is significantly affected by transportation patterns. Ozone action day advisories represent one type of voluntary ozone-abating program operating in urban areas where ozone pollution is concentrated. When forecasts predict that ground level ozone will exceed healthy levels, public advisories urge citizens to voluntarily choose public transportation as a means of eliminating automobile trips and reducing mobile emissions. To obtain credit for emission reductions spurred by voluntary programs, states must provide verifiable reduction estimates. This paper applies a fixed effects regression model to a panel of hourly Chicago Transit Authority train ridership data to evaluate the potential effects of Ozone Action Day advisories in Chicago from 2002 to 2003. Findings show that while the overall effect of ozone action days on ridership is not significant, there are statistically significant changes in hourly ridership patterns that indicate a more complex relationship between the public advisories and travel behavior.     

Freight Demand Management and the Potential of Receiver-Led Consolidation programs

The paper defines the field of Freight Demand Management (FDM), and positions it as an important component of transportation policy and management. To establish the rationale for FDM, the paper studies the effects of the agent interactions at the core of supply chains, and identifies the important role played by the receivers of supplies in determining when and how deliveries are made. The paper classifies the various modalities of FDM, and summarizes the real-life experiences of their implementation. To illustrate the potential of FDM, the paper analyzes Receiver-Led Consolidation (RLC) programs. The paper provides background on consolidation programs, and estimates a behavioral model to shed light on the factors explaining receivers’ interest in cargo consolidation. The resulting model is used to estimate expected participation in a RLC program in New York City. These results are complemented with freight-trip generation analyses, and a behavioral micro-simulation to estimate potential reductions in freight traffic and vehicle-miles-traveled. The results show that RLC programs could bring significant benefits to large metropolitan areas, reducing freight vehicle-miles-traveled and congestion levels.