National Freeway No. 1 Widening Project from Wugu to Zhongli

Project Location

New Taipei City and Taoyuan,

Northern Taiwan


Taiwan Area National Freeway Bureau (TANFB)

Services Period

From April 2009 

to November 2015

Type of Services

Engineering Design and

Construction Supervision

Project Overview

In order to resolve traffic congestion problems on the northern part of National Freeway No. 1 serving the Taipei Metropolitan Area, this freeway widening project commenced in 2009 so as to increase the number of lanes running on a section of freeway from Wugu to Yangmei for a stretch of 40 kilometers. The lanes were added via two new viaducts which were built along the sides of the freeway.


The project presented tremendous challenges owing to its attributes of having limited space for construction, passing by a geologically sensitive area, having to maintain traffic on the freeway, and implementing a complicated design. New and innovative construction methods were introduced to Taiwan for the first time, and CECI played a crucial role as a bridge between the Client and Contractors for fast-tracking the project’s design and construction activities in parallel with each other. After four years of intensive efforts, the entire viaduct was opened to traffic in April 2013.


CECI was commissioned to carry out design and construction supervision services for the northern and middle segments of the project stretching from Wugu District in New Taipei City to Zhongli District in Taoyuan having a continuous length of 28 kilometers and undertook a design emphasizing speed, value and innovation without sacrificing quality and safety. Chief among these design solutions were.

  • Adopting environmentally protective measures including tree transplantation, non-disturbance zones, preservation of habitats, animal escape ways, bat nests, etc.

  • Employing special construction methods, including the horizontal rotation method for the first time in Taiwan, to shorten construction time and avoid disrupting the existing traffic.

  • Optimizing the distribution of construction resources and the design and construction schedules.

  • Creating an “F type” double-deck structure in which both decks use the same supporting columns for a length of 2.857 kilometers to avoid a geologically sensitive area.

  • Designing overpasses for the viaduct to merge into the double-deck structure without impeding the freeway below including a large span structure with a center span having a length of 216 meters, the longest of its kind in Taiwan.

  • Adopting safety and noise reduction measures to maximize performance of the viaduct including low noise expansion joints and infiltration pavement.

Upon its culmination, the “Wu-Yang Viaduct” has been touted for its immediate impact and success in restoring smooth and fast flowing traffic to this section of National Freeway No. 1, and was subsequently awarded as Design Category winner of the prestigious 2015 Global Road Achievement Awards organized by the International Road Federation (IRF).​

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