¿Por qué la gente no usa el Metro? Efectos del transporte en la Zona Metropolitana de la Ciudad de México1

According to available data (2007), the subway of Mexico City transports 13.5% of total passengers; less than any other means of transportation, such as collective taxis (44.9%) or private cars (22.1%) do. This tendency has not changed in 2015. To explain this low mobility, factors such as home-to-station walking distance, station location and density, socio-economic variables, (income, education, sex, age, motive, automobile property), transshipment ability and waiting time were examined.

The analysis revealed: i) that subway users are willing to travel a distance of up to 800 meters in order to arrive to a train station, ii) the resultant buffer of the subway stations is considered an area of influence but it covers only 16.6% of the metropolitan surface area, iii) area known as “walkable” was also considered iv) density of stations is one third of the one at Tokyo and nine times less than at the municipality of Paris. These characteristics are a serious problem for a costly system that still influences the urban structure of the city. Mexico city's subway system register daily: 4.1 million trips as round trips and 2.2 millions one-way trips related to work, school, shopping or entertainment. This next step was to analyze the daily trips from the periphery of the city toward the center that reach up to 1.5 million users, and cause the saturation to seven of the available final stations. In this condition, we have the second hypothesis that there are different logics of decision for the subway use between the “walkable” and periphery citizens.

In the first place, citizens normally choose the subway over other means of transportation aforementioned, (collective taxi, private car, suburban bus or taxi) after taking travel time budget into consideration. In the second place, the amount of passengers who can finish their trips at the station was compared to the amount of passengers who cannot. The analysis showed how the deficient coordination of transportation added to the poor urban planning concentrating only shopping and study areas around the stations affect the population. Therefore, some subway passengers can finish their trips at the stations, while others have to, not just add another means of transportations, but also the walking distance and the waiting time. These issues are associated to the transfer times, “walkable” environment, urban planning and station facilities, such as moving walkway and elevators. Therefore, the users have four options: a) take the subway at least one time in the course of their trips b) choose another means of transportation; c) finish their journeys at the subway stations or d) add another means of transportation after the subway use. Then the logistic regression is applied twice to test the probabilities.

Through the first regression, the obtained value of pseudo R square of Negelkerke (0.38) shows that -contrary to other cities-, passengers use the subway in order to get to work (1.03) less than to go shopping (1.2). The high value of the transshipment variable (41.0) shows the importance of taking this factor into account. The low-income residents (2001 to 8000 pesos per month) use the subway more than the medium-income residents (8001 to 12000 pesos per month). Furthermore, the second regression with pseudo R square of Negelkerke (0.3) reveals that passengers tend to use this modality more to go shopping (0.8) or to their place of study (0.17) than to get to work (-0.2) because the main universities and the traditional market places (mercado) are located around the stations. It is possible to assume that a longer waiting time and a higher number of transshipment may discourage people to travel by subway. Once the odds ratio of walking a distance between 400m and 800m decreases from 8.3 to 5.1, it is possible to assume that a walking distance between 0m and 400m may be the strategic areas to increase its use.

Concluding, it is possible to increase the use of the subway system by improving the functionality at current stations as well as urban areas around them. Finally, some urban planning guidelines are suggested to achieve a more efficient system operation.