Current Features
 Past Features
 50th Anniversary

Top Projects Completed 2003-2004

Triborough Bridge

Rank #20
Cost: $144 million

In 1997, the Metropolitan Transportation Authority began a 16-year, $1 billion project to reconstruct all three portions of the Triborough Bridge. It is the greatest repair job the bridge has seen since it opened in 1936 and is the single largest rehabilitation ever taken by the MTA.

During the current phase, a project that began in December 2002 and completed March 2003, the 60-40 joint venture between Koch Skanska, of Carteret, N.J. and American Bridge Co., of Coraopolis, Penn. involved replacing all 368 suspender ropes and roadway decks on the East River span, as well as the complete re-decking of the existing 2,723-ft. suspension bridge with orthotropic deck panels and the 1,568-ft. Queens Viaduct approach spans with precast concrete deck panels.

The Triborough Bridge is not a single span, but a complex comprised of three long-span bridges, a number of smaller bridges and viaducts, 14 mi. of approach highways and parkways, parks and recreational facilities, and administrative offices for the Triborough Bridge and Tunnel Authority.

The bridge's three branches meet on Randall's Island, where an interchange and two toll plazas sort out traffic flowing in 12 directions and provide access to the island itself.

The project was divided into three phases. The first involved replacing the roadway deck and barriers from the Randall's Island toll plaza to the Queens approach and included the Hell Gate suspension span, the Randall's Island-Ward's viaduct and the Queens viaduct. The suspender ropes on the main span were also replaced.

The second phase involved replacing the roadway deck and barriers from the Randall's Island toll plaza to the Bronx approach and included the Bronx Kills truss span and connecting ramps in the Bronx.

The third phase of the project involved replacing the roadway deck and barriers from the Randall's Island toll plaza to the Manhattan approach and included the Harlem River lift span and connecting ramps in Manhattan.

The replacement systems were pre-formed in 10-ft. by 4-in.-wide panels (the width of one road lane) so that the work would affect traffic flow as little as possible.

After completing the analysis, the team determined that the most efficient alternative was to utilize different types of designs for different deck sections. That included orthotropic panels for suspended spans, precast concrete panels for viaduct/approach sections and precast deck for the truss spans.

In total, more than 1.6 million sq. ft. of deck was replaced.

The project included replacement and rehabilitation designs for the Queens and Bronx approach ramps and viaducts, including steel and concrete structures. Work also included the rehabilitation of pedestrian walkways and ramps to comply with Americans with Disabilities Act requirements and seismic retrofit requirements.

Back to list >>





Learn more about our special supplements and special events

© 2015 The McGraw-Hill Companies, Inc.
All Rights Reserved