The Village of Barrington, Illinois, has begun the design process of reconstructing U.S. Route 14 to pass underneath the heavily traveled Canadian National (CN) rail line that runs through downtown Barrington. The US Route 14 Grade Separation Project includes reconstruction of the four-lane US Route 14, the CN rail line, associated local roads, relocation of Flint Creek, design of the associated Greenway, and construction of a naturalized stormwater basin for the Barrington Public Library.

GZA’s role in the US Route 14 Underpass Project is to provide environmental services through the Phase II transportation design process, including wetland, biological, special waste, and stream restoration design, as well as county, state, and federal permitting.

Notable challenges to this high-profile project include the Flint Creek relocation design associated with the US Route 14 underpass. The Flint Creek crossing is located at the US Route 14 and CN rail intersection. To construct the US Route 14 underpass, the location of Flint Creek must be relocated approximately 1,000 feet to the west. As this project is located in Barrington’s downtown area, the available space for the new Flint Creek channel is limited.


The Village, in conjunction with IDOT, conducted a Preliminary Engineering Study for the grade separation after receiving a Federal TIGER II Planning Grant to investigate alternatives for implementing a grade separation at the existing at-grade crossing. This study followed guidelines prescribed by the Federal Highway Administration (FHWA) in accordance with the National Environmental Policy Act (NEPA). A public outreach program was also developed for the project based upon the principles of the IDOT’s Context Sensitive Solutions Policy (CSS). The CSS is an interdisciplinary approach that seeks solutions by working with stakeholders to develop cost-effective transportation facilities which fit into and reflect a project’s surroundings.

For Phase II of the US Route 14 Underpass Project, GZA will conduct Wetland Delineations and prepare a Wetland Report, Tree Surveys and an associated Memorandum, Individual Section 401 Water Quality Certification, Threatened and Endangered species habitat surveys, Stream Realignment Assessment and Design, Preliminary Environmental Site Assessment (PESA), Preliminary Site Investigation (PSI), Clean Construction or Demolition Debris (CCDD), NEPA Support Services, Natural Areas Design Services, and USACE and Lake County Stormwater Management Commission (LCSMC) Permitting.

Two commercial properties and eight homes will be demolished to accommodate the Flint Creek realignment and US Route 14 underpass. Approximately 1,700 linear feet of Flint Creek will be relocated through the two commercial properties and four homes. In addition to the stream realignment assessment and design, GZA will conduct an Antidegradation Analysis, which will include a full biological assessment of the stream reach including surveys for fish, macroinvertebrates, and mussels, as well as pollutant loading analysis. The remnant stream channel will be left in place and enhanced for stormwater storage, wildlife habitat, and water quality benefit.


Along with the naturalization of a proposed stormwater basin at the adjacent Barrington Public Library, the enhanced old Flint Creek channel and the new Flint Creek Greenway will provide community natural area access in Barrington’s downtown area. GZA’s extensive and detailed reporting, data collection, and design assisted in maintaining project timelines and budgets.