what we do


Designing connections that balance regional mobility and local access

From rural highway off-ramps to complex freeway interchanges, Parametrix helps agencies plan and design interchanges that safely and efficiently move traffic from one road to another. We help agencies with freeway and local operational analysis for highway and local corridors, and have provided analysis for numerous interchange justification reports (IJR), interchange modification reports (IMR) interchange access modifications, and corridor studies. Our staff have developed great working relationships with FHWA and state DOT staff and can guide you through the approval process.

116th Interchange at I-5
I-5/116th Street NE Interchange 
Tulalip, Washington
Client: Tulalip Tribes

The new single-point urban interchange (SPUI) provides needed capacity for current and planned growth in the north Snohomish County area, including the City of Marysville east of the interchange and the Tulalip Tribes’ Quil Ceda Village Business Park west of the interchange. Major elements of the project include an 8-lane, 150-foot-long bridge over I-5, realignment of a major county arterial, realignment of a stream through the interchange, two new 18-foot-diameter stream culverts, a new two-lane 125-foot-long bridge over Quil Ceda Creek, a new roundabout, retaining walls, noise walls, stormwater treatment ponds, and two new signal systems. Parametrix provided design, environmental documentation, permitting, and construction management for the complete reconstruction of the existing diamond interchange.



  • US 550, NM 313 to NM 528

    US 550, NM 313 to NM 528

  • SR 410/Traffic Avenue Interchange

    SR 410/Traffic Avenue Interchange

  • 116th Interchange at I-5

    I-5/116th Street NE Interchange

  • I-84 Karcher to Franklin | Parametrix

    I-84 Karcher to Franklin

  • I-5/Slater Road IJR | Parametrix

    I-5/Slater Road IJR

  • I-84 Meridian Road Interchange

    I-84 Meridian Road Interchange