In the late 1970s, car-centric policies in Mexico City led to the construction of wide arterial roads that reduced travel times and alleviated congestion on smaller streets. Such roads also gave way to an oddity of the city’s public transportation system: Buses that run against the flow of traffic.
On a grid of mostly one-way roads with mixed traffic, so-called counterflow lanes created two-way bus service, helping pedestrians avoid walking roughly 1 km (0.62 miles) to other main arteries to take a bus in the opposite direction.
But a growing recognition of the dangers of such counterflow lanes is leading modern-day Mexico City to re-think the configuration.
“After 30, 40 years, we see now that this design wasn’t the best for the city,” says Alejandro Palmerin, who analyzes transportation policy at the Ministry of Planning and Mobility (SEMOVI), noting the city has modified various roads into bi-directional thoroughfares with center bus lanes for its Metrobus rapid transit (BRT) system.
A Vision Zero policy, which aims to reduce pedestrian deaths, has also turned the city’s attention to bus route safety and the counter-flow design, Palmerin says.
Still, a complete transformation of all one-way streets, which cost roughly $6 million per kilometer to do on the city’s BRT lines over the last decade, appears unlikely.
“You can’t change the whole city from one day to the next,” says Adriana Lobo, a mobility planner at the World Resources Institute, a research organization that found a 146 percent increase in pedestrian crashes and a 35 percent increase in vehicle collisions in counterflow lanes.
“The main risk lies in the fact that counterflow is an unexpected configuration, and many road users may not anticipate vehicles arriving from a counterflow direction,” according to a 2015 study by the organization. “We recommend avoiding counterflow configurations whenever possible and using instead a typical one-way or two-way lane arrangement for streets with bus priority systems.”
For now, the next best solution appears to be optimizing bus corridors by installing better signaling, mid-block crossings, and physical barriers to prevent vehicles and pedestrians from straying into the wrong lane.
For Pablo Perez, 45, a bus driver along Mexico’s zero-emission corridor, there was also another way to navigate counter-flow lanes. “Being more careful and going with the horn,” he says.