Extended abstract for consideration by ITEA Annual Conference and School on Transportation
Economics, June 13-17, 2016, Santiago, Chile
Title:
Can Better Public Transportation Contain the Rise of Motorcycles in Colombia?
Author:
Julian A. Gomez-Gelvez
Ph.D. Student
Department of Agricultural and Resource Economics
University of Maryland, USA
Context and Research Question:
Colombia has experienced an accelerated growth in motorcycle ownership during the last
decade (Figure 1). In 2010, the number of motorcycles in the country exceeded the number of
cars (including automobiles and light-duty vehicles) and they have become a major player in
urban transportation in most cities [1].
Ownership level (veh/1,000 inhab)
120
100
80
60
40
20
0
1990
1995
2000
Cars
2005
2010
Motorcycles
Figure 1: Number of cars and motorcycles per thousand inhabitants in Colombia 1990-2011 [1].
The effects of the rise of motorcycles are twofold. On one hand, the lower costs of
motorcycles in comparison to cars have allowed low- and middle-income inhabitants access
to private transportation. Additionally, motorcycles are in many cases used as a source of
employment to provide informal public transportation (commonly known as mototaxismo)
[2]. On the other hand, the rise of motorcycles has caused an important increase in the
number of road accidents and deaths. In recent years, motorcycle users have accounted for
about 50% of road deaths in the country [3].
In this context, I investigate the relationship between motorcycle ownership and public
transportation accessibility to determine to what extent has the rise of motorcycles in urban
areas in Colombia been prompted by the lack of access to or low service quality of public
transportation. This question is inherently related to the question of whether further
improvements in public transportation will attenuate the current rise of motorcycles.
Data and Methodology:
I base my analysis in two cities: Bogota and Medellin. They are the two largest and richest
cities of Colombia. Their total population is about 8 and 2.5 millions respectively, both with
high population densities around 20,000 inhabitants per squared kilometer.
Both cities have a mass transit system that covers only a portion of the daily public
transportation demand (TransMilenio Bus Rapid Transit (BRT) in Bogota and Metro in
Medellin), while the rest is mainly covered by traditional bus routes without any transit
priority and not integrated to the high-capacity systems. This implies that different zones of
the city have significantly different levels of public transportation accessibility. Zones that are
within walking distance of the mass transit systems are expected to have higher accessibility.
Extended abstract for consideration by ITEA Annual Conference and School on Transportation
Economics, June 13-17, 2016, Santiago, Chile
Between 2005 and 2012, the number of motorcycles in Bogotá and Medellin increased 650%
and 432% respectively [4]. In 2011, Bogotá had 0.101 motorcycles per household and
motorcycles accounted for approximately 2% of daily trips [5]. In 2012, Medellin had 0.176
motorcycles per household and motorcycles accounted for approximately 11% of daily trips
[6].
I use disaggregate information from household mobility surveys carried out in 2011 and 1995
in Bogotá and in 2012 in Medellin to determine whether the growth in motorcycle ownership
has been relatively smaller in areas served by the mass transit systems. The two mobility
surveys available for Bogotá allow me to implement a differences-in-differences
methodological approach to control for motorcycle ownership levels before TransMilenio was
implemented (1995). The analysis for Medellin is purely cross-sectional.
I use an ordered response probit (ORP) to model motorcycle ownership by households in both
cities. The ORP model assumes that a single continuous variable represents the propensity of
households to own motorcycles. It then uses thresholds in order to discriminate the different
ownership levels (number of motorcycles owned by a household) on the underlying
propensity. The ORP model has been used successfully in the past to analyze motorcycle
ownership [7] [8] [9] [10].
The explanatory variable of interest in the model is whether the household resides within
walking distance of a station (dummy variable). A different variable is used to analyze the
effect of residing close to the feeder routes of the systems (bus routes for TransMilenio and
cable-car lines for Metro). Control variables include income and household size by
occupation, age, gender and distance to work.
Results:1
The results for Bogota show that the propensity to own motorcycles increased less between
1995 and 2011 for households within walking accessibility to TransMilenio’s stations (this
effect is significant at a 6% level of confidence). This implies that TransMilenio did partially
contain the increase in motorcycle ownership levels in Bogotá. The effect was not significant
for households with access to feeder routes. This result is likely due to the lower service
quality provided by feeder routes (which require a transfer to the trunk system). Besides the
effect of access to TransMilenio, the results reveal that the propensity to own motorcycles has
increased more importantly for households with young male adults living far from work.
The results for Medellin indicate that access to Metro or the cable-car lines does not have an
impact on the propensity to own motorcycles. This effect was estimated separately for
different income ranges (through interaction terms), with the effect on middle-income groups
being negative but only slightly significant.
References:
[1] Ministerio de Transporte, República de Colombia. Transporte en Cifras. 2013.
[2] Acevedo, J., J. P. Bocarejo, J. C. Echeverry, G. Lleras, G. Ospina and A. Rodriguez. El
Transporte como Soporte al Desarrollo de Colombia: Una Visión al 2040. Ediciones
Uniandes, Bogotá, 2009.
[3] Corporación Fondo de Prevención Vial y Universidad de los Andes. Anuario Estadístico
de Accidentalidad Vial Colombia 2011. http://www.fpv.org.co/uploads/documentos/libreria/
anuario_2011_pagina.pdf Accessed July 18, 2014.
1
Tables of estimated coefficients and standard errors are not included in this extended abstract.
Extended abstract for consideration by ITEA Annual Conference and School on Transportation
Economics, June 13-17, 2016, Santiago, Chile
[4] Secretaría Distrital de Movilidad de Bogotá D.C. Movilidad en Cifras 2012.
http://www.movilidadbogota.gov.co/hiwebx_archivos/audio_y_video/final%20cifras%20201
2.pdf
[5] Secretaría Distrital de Movilidad de Bogotá D.C., Steer, Davies and Gleave and Centro
Nacional de Consultoría. Encuesta de Movilidad 2011: Informe de Indicadores.
http://www.movilidadbogota.gov.co/hiwebx_archivos/audio_y_video/Encuesta%20de%20M
ovilidad.pdf
[6] Sarmiento, I., J. Cordoba, C. Diaz and C. Gonzalez-Calderon. Important Aspects to be
Considered in Household Travel Surveys in Developing Countries. Presented at 92nd Annual
Meeting of the Transportation Research Board, Washington, D.C., 2013.
[7] Gómez-Gélvez, J.A., and C. Obando. Joint Disaggregate Modeling of Car and
Motorcycle Ownership: Case Study of Bogotá, Colombia. In Transportation Research
Record: Journal of the Transportation Research Board, No. 2451, Transportation Research
Board of the National Academies, Washington, D.C., 2014, pp. 149-156.
[8] Anastasopoulos, P.C., M.G. Karlaftis, J.E. Haddock and F.L. Mannering. Household
Automobile and Motorcycle Ownership Analyzed with Random Parameters Bivariate
Ordered Probit Model. In Transportation Research Record: Journal of the Transportation
Research Board, No. 2279, Transportation Research Board of the National Academies,
Washington, D.C., 2013, pp. 12-20.
[9] Senbil, M., J. Zhang and S. Fujiwara. Motorization in Asia – 14 Countries and Three
Metropolitan Region. IATSS Research, Vol. 31, No. 1, 2007, pp. 46-58.
[10] Sanko, N., D. Dissanayake, S. Kurauchi, H. Maesoba, T. Yamamoto and T. Morikawa.
Inter-Temporal Analysis of Car and Motorcycle Ownership Behaviors: The Case in the
Nagoya Metropolitan Area of Japan, 1981-2001. IATSS Research, Vol. 33, No. 2, 2009, pp.
39-53.