The expansion of Lima’s integrated public transport system extends 10.2 km through the districts of Comas and Carabayllo in the North Cone of Peru’s capital and largest city—an area previously known for chaotic traffic, numerous informal private bus services and an organized crime presence. It was a conflict-ridden zone that posed significant risks to worker safety and to building the new connector.

The project—known as the high-capacity Corridor North Extension, or by its Spanish acronym, COSAC—was built by a team led by contractor Obrascon Huarte Lain Sucursal del Perú (OHLA). It includes a 10.2-km segregated bus lane for use only by public transport buses within the central median of the city’s arterial roads. Work also included constructing two main lanes, two side separators and two service lanes adjacent to property lines.

Chimpu Ocllo terminal station (top) is part of the COSAC Corridor North (right). The workshop yard was once a landfill.
Photo courtesy of OHLA

The team also designed and built 17 stations equipped with access ramps, control modules, boarding modules and maneuvering areas for the buses—part of the $538-million project that has been adding public transit routes to Lima since 2010.

OHLA employed local labor, with a workforce development program that included training. Building modern infrastructure with extensive landscaped areas was also beneficial for economically depressed communities in the city such as Comas and Carabayllo. Throughout, traffic was managed.

Photo courtesy of OHLA

“Ensuring smooth traffic flow during construction was a major challenge,” OHLA noted in its contest entry form. “Twelve phased traffic diversion plans were implemented, guiding construction activities through clearly demarcated sectors, monitored at intersections.”

Construction of urban green spaces reduced airborne dust levels, a cause of respiratory disease. Systems to reinforce foundation soil and control settlement were implemented to mitigate building on a landfill site for the project’s workshop and maintenance yard. In all, OHLA built more than 180,000 sq m of green areas, and a new wastewater treatment plant as part of the project. Treated water now is used to water the plants. The scheduled time frame and budget were met.