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I-78 and Garden State Parkway Interchange 142 Improvement Project

Reducing inefficiency, gridlock, and danger on two of New Jersey’s busiest superhighways.
  • Mon/Fayette Expressway Uniontown to Brownsville-Gannett Fleming

    The completed I-78 and Garden State Parkway Interchange 142 greatly improves traffic flow.

  • I-78 westbound to the GSP northbound ramp and the GSP southbound to the I-78 east ramp

    This high traffic interchange in a mature urban setting required noise monitoring, studies, and noise wall design.

  • GSP Northbound to I-78 and GSP Interchange 142-Gannett Fleming

    The opening of movement from GSP northbound to the I-78 westbound ramp eliminated a two-mile U-turn.

  • Bridge girders on I-78 eastbound spanning the Elizabeth River Bridge-Gannett Fleming

    Setting of bridge girders on I-78 eastbound spanning the widened Elizabeth River Bridge.

  • Drilled shaft foundations and columns under I-78 westbound to GSP-Gannett Fleming

    Drilled shaft foundations and columns under I-78 westbound to the GSP ramp.

New Jersey Turnpike Authority

Modjeski and Masters, T.Y. Lin International Group, GTS Consultants, Robinson Aerial Surveys, CME Associates, AmerCom, Paul Carpenter Associates

Union and Essex Counties, New Jersey

Our Role
Civil, Structural, Facilities Design, Environmental, Construction Engineering.

Construction Cost
$165 million
New Construction
8 years
  • Coordinated interagency cooperation to satisfy regulatory demands
  • Completed project six months ahead of schedule with minimal change orders
  • Saved $40 million in project costs with an innovative financial plan
  • Solved a 30-year congestion problem and reduced commute times by 20 minutes.

The Garden State Parkway (GSP) Interchange 142 Improvement Project was a large-scale, $165 million rehabilitation and reconstruction project that solved a 30-year congestion problem for two of New Jersey’s busiest superhighways. By providing the two missing movements between the GSP and I-78, this project eliminates approximately 1,200 vehicles-per-hour from making a two-mile U-turn and nearly 250 vehicles per-hour from exiting the GSP to use local roads. 

Eliminating these inconvenient maneuvers with ramps in both directions saves more than 23,000 motorists up to 20 minutes at peak travel times daily and keeps highway traffic on the highway. These connections also enhance safety and operations at the interchange with improved sight distance, wider ramp geometry, and increased weaving distance.

What We Did

As project designer, Gannett Fleming provided preliminary and final design, including civil, structural, facilities design, environmental services, and construction engineering for completion of the improvements to Interchange 142 on GSP and I-78. We performed alternative analysis, National Environmental Policy Act (NEPA) environmental re-evaluation, preliminary and final design, and construction support services. The mature urban setting of this project site presented a variety of challenges in traffic safety and urban redevelopment and required many innovative, cost effective, and unique solutions. Real-time travel alert technology and staging of reconstruction minimized impacts on these high-traffic superhighways. Mechanically stabilized earth retaining walls supported by controlled modulus columns were utilized to improve the soil prior to construction, and a distressed property purchased and utilized as a staging area during construction, then transformed for public use, saved the project $2 million.

This project featured a unique joint-agency endeavor among the New Jersey Turnpike Authority, the New Jersey Department of Transportation, and the Federal Highway Administration that saved taxpayers more than $40 million. Gannett Fleming developed a breakthrough financial management plan  that supplemented the cost-sharing agreement executed by the three public agencies. We ensured the appropriate amount of money was programmed and budgeted and planned for contingencies. This enabled the project team to deliver the project six months ahead of schedule.

Key Features

  • Construction of 20 new or modified retaining walls
  • Construction of five new bridges, including three new flyover ramp structures and two simple-span structures
  • Construction of six new or reconstructed ramps, totaling more than 12,000 linear feet
  • Installation of 13 new or modified sign structures
  • Reconstruction of one mile of I-78 eastbound and westbound local and express roadways
  • Relocation of 2,000 linear feet of noise wall
  • Widening of auxiliary lanes along I-78
  • Widening of 10 interstate bridges.

Sustainability Features & Outcomes

  • Created soil reuse plan and groundwater control measures
  • Eliminated waterway piers to minimize environmental impact to the Elizabeth River
  • Established best management practices to address water quality
  • Implemented of soil erosion and sediment control measures
  • Studied noise impact and its’ community affect.

Awards & Recognition

  • Grand Honor Award, 2012, American Council of Engineering Companies New Jersey, Engineering Excellence Awards
  • National Recognition Award, 2012, American Council of Engineering Companies, Engineering Excellence Awards
  • No. 2 Bridge, 2011, Roads & Bridges, Top 10 Bridges
  • No. 8 Roads, 2011, Roads & Bridges, Top 10 Roads
  • Outstanding New Medium Span Bridge Award, 2012, Association for Bridge Construction and Design, Susquehanna Chapter, Bridge Awards
  • Project of the Year award, 2012, American Society of Highway Engineers, Outstanding Highway Engineering Awards.

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