The Utah Department of Transportation (UDOT) is preparing the Parley’s Interchange Environmental Impact Statement (EIS) to evaluate the short- and long-term needs of the I-80/I-215 eastside interchange. The purpose of the study is to improve safety, reduce congestion, increase regional mobility and update the current design of the interchange.


Parley’s Interchange has not had a capacity or major safety upgrade since its completion in the mid-1960s. Parts of the interchange have accident rates above the state average for similar facilities.

Traffic Flow

Parley's interchange is congested during the morning and evening peak commutes, with traffic backing up onto the freeway travel lanes.

Regional Mobility

The travel delay through the interchange has reduced regional mobility for passenger and freight traffic that use this critical local and national link of the interstate system.

Updated Design

Parley’s Interchange does not meet current design and safety standards.

The environmental review, consultation, and other actions required by applicable Federal environmental laws for this project are being, or have been, carried-out by UDOT pursuant to 23 U.S.C. 327 and a Memorandum of Understanding dated January 17, 2017, and executed by FHWA and UDOT


Level of service is a measure of the quality of traffic at an intersection of roadway, ranging from Level A (free flowing traffic) to Level F (forced flow, or very congested).




Low volumes and no delays.



Speeds restricted by travel conditions, minor delays.



Speeds and maneuverability closely controlled because of higher volumes.



Speeds considerably affected by change in operation conditions. High density traffic restricts maneuverability; volume near capacity.



Low speeds; considerable delay; volume at or slightly over capacity.



Very low speeds; volumes exceed capacity; long delays with stop-and-go traffic.

The purpose of the Parley's Interchange project is to improve safety, reduce congestion, increase regional mobility and update the current design.

Study Area

The Parley’s Interchange is a key regional connection for all travel modes from southeast Salt Lake County and Summit County, providing connections to the University of Utah, Research Park, Millcreek and downtown Salt Lake City. The interchange also provides an important connection to Park City from the Wasatch Front and is a critical local and national freight route.

Study Area Map
Salt Lake Country Club
Parley's Historic Nature Park
Tanner Park
Sugar House Park
Stringham Ave Intersection
Parley's Way Park
I-80 Exit 132
EIS Study Area


EIS Scoping

FEB - MAR 2018

Alternative Development

APR 2018 - SEPT 2018

Draft EIS (DEIS)

SEPT 2018 - JUNE 2019

Public Hearing / Comments on DEIS

JUNE - AUG 2019

Final EIS (FEIS) and Record of Decision (ROD)

AUG 2019 - FEB 2020
Ongoing Agency Coordination and Public Involvement


UDOT will consider a range of alternatives that meet the purpose and need for the project, and are based on agency and public input.


Noise Questions & Answers

The Utah Department of Transportation (UDOT) Noise Abatement Policy is the official policy and procedure for the Department in regards to noise abatement studies, implementing measures, and coordination with local municipalities and the public. This is the process by which all feasible and reasonable mitigation measures are incorporated into projects to minimize noise impacts and protect the public health and welfare.

For your convenience, we have simplified the policy and highlighted sections that relate to the Parley’s Interchange EIS. You can also read the full Noise Abatement Policy and Draft Noise Report: Existing Conditions online.


The Parley’s Interchange EIS is considered a Type 1 project because it will modify the horizontal and vertical alignment of existing highways. For Type 1 projects, UDOT will evaluates noise abatement for areas with noise impacts from the project.

Analysis of Traffic Noise Impacts

The traffic noise analysis will include the following:

  • Identification of existing developments and undeveloped lands for which development is permitted.
  • Determination of existing and future worst case noise levels.
  • Determination of traffic noise impacts.

UDOT considers a traffic noise impact to occur when either of the following situations is expected:

  • The future worst case noise level is greater than or equal to an increase of 10 decibel (dBA) over the existing noise level. This impact criterion takes effect regardless of existing noise levels.
  • The future worst case noise level is equal to or greater than the UDOT Noise Abatement Criteria for each corresponding land use category. Common land use categories and their corresponding Noise Abatement Criteria include the following:
    • Residential properties: 66 dBA
    • Schools and public or private recreational areas (e.g. parks, trails, golf courses): 66 dBA
    • Commercial properties (e.g. hotels, motels, offices, restaurants and developed lands): 71 dBA

Analysis of Noise Abatement

The two relevant criteria to consider when identifying and evaluating noise abatement measures for mitigation are feasibility and reasonableness.

  • Feasibility includes engineering considerations, safety on urban non-access controlled roadways, and acoustic feasibility. To be considered feasible, noise abatement measures must provide a 5 dBA or greater reduction for at least 50 percent of the front-row receptors.
  • Reasonableness looks into the noise abatement design goal, the cost effectiveness of setting up noise abatement measures, the viewpoints of property owners and residents via balloting, and the noise receptor locations. To be considered reasonable, noise abatement measures must:
    • Provide a 7 dBA or greater reduction for at least 35 percent of the front-row receptors.
    • The cost of the noise abatement measure cannot exceed $30,000 per benefitted receptor (for residential properties) or $360 per linear foot for other sensitive land use categories.
    • At least 75 percent of the ballots sent out on the proposed noise abatement measure must be returned.
    • At least 75 percent of the returned ballots must favor the proposed noise abatement measure.

Noise Abatement Measures

The following abatement measures may be considered, including a cost/benefit analyses to compare alternatives, if a noise impact is identified:

  • Traffic Management Measures, such as truck restrictions or reducing speed limits
  • Noise barriers

Noise abatement measures analyzed and deemed feasible and reasonable in the environmental study phase are still subject to final design and balloting.

Relocation of Existing Noise Barriers

There may be circumstances when existing noise barriers must be relocated or replaced due to conflicts with new construction projects, and where the barriers do not meet new specified criteria. Existing barriers will most often be relocated or replaced in-kind.

Traffic Noise Prediction

Only the current FHWA-approved Traffic Noise Model (TNM) is used for any traffic noise analysis, unless otherwise agreed upon in advance by the Department and FHWA.


The Parley's interchange is a critical link in the regional transportation system.

Contact Us

parleysEIS@utah.gov 801-743-7885
Enter an email or phone above if you'd like to be contacted. Por favor contactenos al 801.743.7885 ó parleysEIS@utah.gov para información en Español.