Development that Works
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    This blog highlights effective ideas in the fight against poverty and exclusion, and analyzes the impact of development projects in Latin America and the Caribbean.
  • Traffic jams



    congestion engIn 1966, the incredible Julio Cortazar published a short story called ‘The Southern Thruway’. An accident happens in a lazy summer afternoon and traffic grinds to a halt.

    Nothing moves. Everybody waits.

    One by one people get out of their cars to stretch their legs and some start chatting. Traffic is stuck. Night slowly falls. The engineer in the Peugeot and the woman in the Dauphine fall in love. Some sleep. Dawn comes and the way to Paris is still closed. Suddenly one car starts and moves 5 yards. Another one. Everybody runs to their car.

    They say goodbye.

    In one lane the Dauphine moves and in another the Peugeot crawls away. Very slowly at first. The Dauphine is three cars ahead. A few miles later the Peugeot can barely be seen. They won’t see each other again, as a sea of red lights engulfs them.

    On these more prosaic days, air pollution and traffic congestion are increasingly serious issues in Latin American cities. Two relatively recent experiences show that some solutions can be effective in the short term but not in the long term.

    Nowadays it is considerably more difficult than 50 years ago to convince drivers to leave their cars behind. Even for a few hours of temporary happiness.

    In an effort to reduce air pollution and congestion, Latin American cities have experimented with different policies to persuade drivers to give up their cars in favor of public transport. This paper looks at two of such policies: the driving restriction program introduced in Mexico-City in November of 1989 –Hoy-No-Circula (HNC)– and the public transport reform carried out in Santiago in February of 2007–Transantiago (TS). Based on hourly concentration records of carbon monoxide, which comes primarily from vehicles exhaust, we find that household responses to both HNC and TS have been ultimately unfortunate –more cars on the road and higher pollution levels– but also remarkably similar in how fast households have adjusted their stock of vehicles, within a year. Another empirical finding is how different short- and long-run effects of the policies can be. In fact, we find that a (permanent) driving restriction like HNC can still be effective in the short-run, say, for a month or two.

    The paper

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