BergerWorld: 3rd Quarter 2004

The concept of the limited access highway was one of the most significant transportation innovations of the 20th century. By limiting and controlling the number of intersections on a highway, traffic could reach higher speeds with fewer accidents. But a number of these interchanges have exceeded their original design capacity. To accommodate increased traffic volume, the Berger Group is upgrading interchanges around the country.

In 1965, the Washington State DOT constructed a classic cloverleaf interchange which allowed continuous access between Interstate 5 and State Routes 18 and 161 just north of the Pierce County line. Since the 1960s, areas surrounding the interchange have grown significantly. Current traffic congestion often extends beyond peak morning and evening rush hours and the interchange is identified as a high-accident density location.

Berger/ABAM Engineers Inc. was selected by WSDOT to design an improved interchange providing a direct connection between I-5 and SRs 18 and 161. During the design phase, the Team identified several alternatives to reduce congestion and improve safety, then selected and designed the most attractive alternative and completed a combined national and state environmental assessment and an access point decision report.

The cloverleaf interchange at Route 1 and Walnut Street in Saugus, Massachusetts has been consistently ranked one of the most dangerous in the state because the interchange's short acceleration/ deceleration lanes and tight turning radii make it difficult for drivers to merge with heavy traffic from nearby businesses. In recent years, it became increasingly clear to town planners and MassHighway officials that the original interchange, built in the 1950s, could no longer handle the current volume of traffic.

The Berger Group was selected to replace the full cloverleaf design with an interchange better suited to handle current and future demand. The design was complicated by the need to ensure adequate access remained available to businesses, offices and shoppers during construction. Local residents also expressed concerns over any increase of traffic on Walnut Street. To build consensus for the project, Berger implemented a comprehensive public involvement strategy, meeting with local business owners, civic groups and local residents to establish project goals and encourage local support.

Based on these concerns and suggestions, Berger designed an innovative partial cloverleaf and state-of-the-art traffic signal system to replace the existing interchange. The new design will eliminate the dangerous traffic movements on Route 1 which contributed to the high accident rates and widen the existing overpass to four lanes, allowing drivers to readily access nearby businesses.

Each day, more than 250,000 riders from the New Jersey suburbs use New Jersey Transit (NJT) trains to access New York City. As part of an effort to reduce congestion and increase ridership, NJT constructed the $1 billion Frank Lautenberg Multi-Modal Transportation Center in Secaucus, NJ, to provide riders with a state-of-the-art transit hub.

To support this new complex, the New Jersey Turnpike Authority selected RBA and the Berger Group to prepare preliminary designs for a $120 million link between the Turnpike and the station. Following approval, Berger was selected to develop final designs and provide construction supervision for a viaduct connecting the toll plazas at exit 16X on the NJ Turnpike with Seaview Drive near the new station. The commission presented Berger with a number of challenges. The area around the project site contained both commercial properties and sensitive wetlands. To reduce the impact on vital wetland areas, Berger recommended a raised interchange above wetland areas. The interchange design had to address a number of other issues, including the highly compressible soil structure of the Hackensack Meadowlands. Berger conducted a number of seismic tests to develop a design capable of withstanding a major earthquake, then created detailed plans for a complex horseshoe-shaped ramp to carry traffic over NJT lines.

Throughout the construction process, the Team worked closely with the NJT and the NJDOT to coordinate the construction schedule to minimize train delays and reduce traffic backups on the Turnpike. As a result of this well planned coordination process, rail commuters, Turnpike users and other traffic were seldom inconvenienced. The construction of the Frank Lautenberg Station is a major step in the comprehensive plan by NJ Transit and the Port Authority of New York and New Jersey to provide improved access to New York City.