Transportation Research Part A: Policy and Practice
Taxi owners’ buying preferences of hybrid-electric vehicles and their implications for emissions in New York City
Introduction
The iconic New York City (NYC) yellow taxi has started to undergo an image change with the introduction of hybrid-electric vehicles (HEVs) to the automobile industry (Mantyk, 2005). There are 11 vehicles listed on the Taxi and Limousine Commission (TLC) website for use as approved taxicabs, 9 of which are HEVs. As of December 2006, there were 283 HEVs in a fleet of 13,087 NYC taxicabs. In light of rising gas prices and increase in the public’s awareness of environmental responsibility, HEVs have gained attention due to their high gas mileage ratings. The borough of Manhattan’s layout makes it typical of stop-and-go city driving, for which HEVs show significant advantage in fuel economy by making full use of regenerative braking technologies. These braking systems allow the reuse of energy that is typically lost as heat due to friction when brakes are applied (Cikanek and Bailey, 2002). HEV engines recapture this energy and store it in a battery, which is then used to power the vehicle from a standstill. For city driving, this means higher mileage ratings and less gas expenses for vehicle owners, and reduced emissions and air quality impact for the public.
A simple calculation indicates that a conversion to a 40 MPG (city) hybrid-electric vehicle would save the average NYC taxi operator $14,025 over the 3 year life of each vehicle.2 Additionally, the US government has offered tax credits to buyers of hybrids of up to $3000 depending on model, but this incentive is set to expire in 2009 and the full amount of the tax credit is only available until the 60,000th vehicle of that model is sold. After the sale of the 60,000th vehicle, the tax credit for that model decreases slowly over the next 15 months, after which the tax credit incentive ceases to exist (US Department of Energy, US Environmental Protection Agency, 2007). Since it is financially sound for taxi owner-operators to convert to HEVs, there is likely to be a trend towards them in the near future. HEV annual sales have the potential to capture 10% of all light-duty vehicle sales in the US after 2011, with this penetration rate being highly sensitive to both increased gasoline prices and increased consumer awareness (Cao and Mokhtarian, 2004).
NYC yellow cabs in service are operated in two major ways: some are individually owned and operated while others are owned by private fleets and leased to drivers. The private fleets are run as corporations and a single company can own hundreds of vehicles. While it makes sense for fleets to purchase the least expensive vehicle with lowest maintenance costs, it makes sense for drivers to drive HEVs due to their lower gasoline consumption. The result is that demand for HEVs by non-owner-operators rises, but supply by fleets may not necessarily meet the elevated demand. In order to gather information about the fleets’ buying tendencies, fleet managers were called by telephone and were asked a series of questions by the authors, which will be discussed in the following section.
Based on 2005 data, 3550 cabs (27%) were driven at least part-time by the owner of the taxicab (Schaller Consulting, 2006). Using this number as a target population, the authors designed another survey that was administered to these owner-operators to gather data on taxi owners’ attitudes toward HEVs.
Survey methods for the study are presented in the following section, which is followed by survey results and statistical data analysis. A discussion follows the survey data analysis to translate NYC taxi owner’s buying preferences of HEVs into potential emission changes and policy implications. The paper concludes with the major findings of the study.
Section snippets
Individual owner’s survey
The primary purpose of the owner’s survey is to find out from current and prospective owners of NYC taxicabs what vehicle they will purchase next for use as a NYC taxicab. A secondary purpose of the survey is to relate certain social-economic characteristics, such as age, experience, and income, to the decision of whether or not an owner or prospective owner would buy an HEV. The main idea is to find out the likely penetration rate of HEVs in the NYC taxicab market to project a breakdown of the
Individual owner’s survey
The surveyors encountered an unanticipated problem with their target population: language barrier. Ninety-one percent (91%) of taxi drivers are foreign-born; the vast majority of which do not speak English as their first language. The surveyors made the decision to interview as many taxi drivers as possible in a cafeteria in the airport taxi holding lot. The conversational aspect of the interviews left some of the surveys incomplete, so the surveyors decided to administer the surveys as
Discussion
The results of this survey research indicate that we can expect the NYC taxi fleet to transform considerably in the next 5 years. The environmental impact of the fleet conversion should prove to be important, given the decreased emissions of HEVs. For the purpose of demonstration, vehicular emissions from the NYC taxi fleet are estimated below for both current and future fleet compositions.
The March 2006 NYC taxi fleet was comprised of 11,459 Ford Crown Victorias, 1103 Toyota Siennas, and 217
Conclusion
The survey study indicates that without government intervention 9.35% of the overall future (5 year) NYC taxi fleet will be comprised of HEVs. Thirty-four percent of current and prospective individual NYC taxicab owner-operators will prefer purchasing a HEV as their next vehicle. Factors relevant to the individual taxi owner’s decision of whether or not to buy an HEV include age, experience, and income. A binomial logistic regression model was estimated from the data that can be used to predict
Acknowledgements
The authors would like to thank Samara Epstein, Director of Constituent Affairs, NYC Taxi and Limousine Commission, and Mark Simon, Director of Alternative Fuels Program, NYC Department of Transportation for their inputs about NYC taxi operations/management and relevant NYC HEV policies. We are in praise of Lynn Johnson for her statistical acumen and advice. We are also grateful to Steven Nguyen, Aaron Levine, and JFK Airport Central Taxi Holding Lot personnel for their help in administering
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