Project Information

About the New Mix Program

The New Mix is a long-term program being undertaken by the Connecticut Department of Transportation (CTDOT) that will plan and implement a series of projects to address the long-term needs of Waterbury’s I-84/Route 8 interchange—commonly referred to as the “Mixmaster”.

The Mixmaster was planned and designed approximately 70 years ago and opened for public use in 1968.  When it was originally built, the structural components of the Mixmaster had an anticipated lifespan of approximately 50 to 60 years, which has been extended through multiple, major rehabilitations.

Innovative in its design and engineering for the time, the Mixmaster features stacked bridges. Building upward with stacked bridges was an engineering feat which allowed a smaller footprint and economic efficiency and also addressed the area’s challenging topography.  However, the stacked bridges of the Mixmaster make both rehabilitation and replacement a complicated endeavor.

The existing interchange is currently undergoing a major structural rehabilitation.  When completed, this rehabilitation is expected to extend the life of the Mixmaster for up to 25 years.  At that point, continued rehabilitation and repair of vital structural components will need to be reassessed from an economic and structural life-cycle perspective. There is a limit to how much the lifespan can be feasibly extended for the interchange’s steel frames and concrete decks upon which cars travel.

Safety and operational standards for roads and highways have evolved significantly since the Mixmaster was designed, which will also be taken into consideration as planning progresses. Components of the interchange such as roadway geometry (sight distance, sharpness of curves, and lane alignment), standardized shoulders, left-hand entrances and exits, spacing of interchanges and ramps, and traffic volumes will all be taken into consideration during the planning process.

Preparation for the New Mix is a complex and long-term endeavor: reconstruction of an interchange of this magnitude, whether through replacement or an intensive rehabilitation, requires a large amount of time and advanced planning in order to properly phase and fund the program. Therefore, the New Mix program will likely be phased with breakout projects that will occur over a number of years. Through each stage of the process, CTDOT will engage the public and stakeholders, providing numerous opportunities for public input. 

Each set of breakout projects is intended to complement and work to advance the overall New Mix Program through incremental improvements. The potential phasing of breakout projects is described below.

Early Action Projects

Early Action Projects will generally focus on local road and intersection improvements with the intended goal of improving the function of the overall local road network without intensive construction or construction impacts. By improving the functioning of the local road network, Early Action Projects are also intended to improve the flow of traffic in the area. As Early Action Projects are smaller in scope, they may occur relatively soon, as early as the mid-2020s.

Near-term Projects

Near-term Projects will generally occur on the outer portions of the interchange and could include improvements to entrances, exits, and lane configurations that improve the function of the existing interchange approaches but are also aligned with the goals of the future improvements to the core of the interchange. Near-term Projects will also facilitate traffic handling during the eventual core interchange reconstruction. Some, but not all, Near-term Projects will require more extensive construction and may result in impacts to drivers. Near-term Projects may begin construction in the early 2030s, before the core of the interchange is reconstructed.

Long-term Projects

Long-term Projects include significant construction work that will be required to reconstruct the core of the interchange. Long-term Projects could include replacement or reconstruction of decks, the stacked bridges, and other elements of the interchange and connections between Interstate 84 and Route 8. Construction of Long-term Projects is anticipated to begin in the vicinity of the mid-2030s to the early 2040s. 

The New Mix program will modernize the I-84/Route 8 interchange to meet current safety, structural, and operational standards, improve safety and functionality of the interchange, reduce the amount of time commuters spend stuck in traffic, complement the economic development goals of the City of Waterbury, and serve Connecticut’s transportation needs for decades to come.

Current Work: The Planning and Environmental Linkages Process

CTDOT is using the Planning and Environmental Linkages (PEL) process during the early planning phases of the New Mix.

Developed by the Federal Highway Administration (FHWA), the PEL process considers and incorporates environmental, community, and economic goals in the very early planning and design phases of transportation projects or programs.

Through the PEL process, CTDOT will work with the community to define transportation related goals and objectives as well as the purpose and need for the New Mix. Following this, CTDOT will work with the community to review various early conceptual design options for the New Mix, measuring each against the program’s established Purpose & Need and Goals & Objectives statements.

Public involvement during the New Mix PEL process will be multi-faceted and will include meetings with stakeholder groups and the general public and will also include the formation of a Project Advisory Committee (PAC). The PAC will have broad community representation, including but not limited to, ‘immediate abutters’ which are residential and business districts located in or nearby the interchange; emergency service providers; Waterbury’s Mayor and Board of Alders; various Waterbury department heads including Engineering, Public Works, and City Planning; and the Chamber of Commerce and large employers with commuters who travel the interchange daily.

The first PEL public meetings are scheduled to occur in 2021. Please sign up for our email list here to be notified of public meetings and other program news.

PEL OVERVIEW

The graph below provides an overview of the various phases of the PEL process, which is anticipated to take approximately 2 years.

Project History

As the national interstate system was taking shape across America in the 1950s and 1960s, Connecticut was also working diligently to connect the state’s population centers to each other and to other states to advance commerce, recreation, and to improve emergency service access.

Rendering circa 1960

Rendering circa 1960

Many highway projects were in development or construction in Connecticut during this era, including the planning, design, and construction of Interstate 84 and Route 8. These routes were to intersect in Waterbury, allowing drivers to move from one highway to another without having to leave the high-speed environment and change routes via local roads.

The planning for the I-84 and Route 8 interchange in Waterbury—now referred to as the Mixmaster-- began in the 1940s and continued through the 1950s.  Construction on the Mixmaster occurred in the 1960s. The completed interchange was opened for public use in 1968 and quickly became an integral part of Connecticut’s transportation network.

The design and construction of the Mixmaster interchange was innovative for the time. A key feature of the Mixmaster is the “stacked bridges” that were built above one another. An engineering marvel for the time, these stacked bridges created a smaller footprint across the City of Waterbury in terms of both land use and economic cost, while also addressing the challenges of the area’s topography.

When originally built, the Mixmaster had a projected lifespan of 50-60 years which has been extended through multiple, major rehabilitation projects. The current rehabilitation project is expected to extend the Mixmaster’s lifespan up to 25 years.

In 2018, CTDOT began to analyze whether yet another major rehabilitation project—to occur in 2045 and referred to as the 2045 Rehabilitation Analysis —would be a cost-effective way to further extend the Mixmaster’s lifespan and address functionality issues.

The 2045 Rehabilitation Analysis showed that despite a cost of approximately $1 billion, another rehabilitation in 2045 would not substantially improve the interchange’s functionality, nor would it significantly extend its lifespan relative to the cost of a full replacement. There is a limit to how much the lifespan can be extended for the interchange’s steel support structures and for the decks upon which cars travel.

The 2045 Rehabilitation Analysis also found that continued rehabilitation would not be able to address operational and safety standards, which have evolved since the interchange was originally designed and constructed. These standards include roadway geometry (sight distance, sharpness of curves, and lane alignment), standard shoulders, spacing of interchanges and ramps, and left-hand entrances and exits.

In 2017 traffic volumes on the interchange stood at approximately 190,000 trips per day almost double the intended capacity of the system. By 2045, that number is expected to reach close to 225,000 vehicle trips per day. Planning for the safe maintenance of traffic flow during replacement of the stacked bridges presents another engineering challenge.

Public Involvement will be integral throughout the New Mix Program. Designers will face many of the same challenges they did originally, such as finding ways to integrate the New Mix design with the topography, historical landmarks, residential areas and local businesses, and the City of Waterbury’s development goals.

The New Mix will improve safety and functionality of the interchange, reduce the amount of time commuters spend stuck in traffic, complement the economic development goals of the City of Waterbury, and serve Connecticut’s transportation needs for decades to come.

FAQ

What is the Mixmaster?

The Mixmaster is the commonly used name for the interchange where Route 8 (North and South) and Interstate 84 (East and West) meet in Waterbury.

The Mixmaster was planned and designed in the late 1940s through the 1950s, was constructed in the 1960s and opened for public use in 1968.

Several of the interchange’s bridges were built ‘stacked’ above one another. Building up with stacked bridges allowed the footprint of the interchange to take up less land in Waterbury while also addressing the design challenges presented by the area’s steep slopes and the need to span across the Naugatuck River.

The design of the Mixmaster was innovative for its time and the interchange remains the only stacked section of two-way highway in Connecticut.

What is the lifespan of the Mixmaster?

When first opened for public use in 1968, the then-new Mixmaster had an approximate lifespan of approximately 50-60 years, which has been extended through multiple, major rehabilitations.

What construction has recently been occurring on the Mixmaster?

Most recently, CTDOT began an intensive rehabilitation project on the interchange called the Mixmaster Rehab Project. Initiated in 2018 and scheduled for completion in June 2023 the Mixmaster Rehab Project is expected to extend the life of the Mixmaster for up to 25 years.  Learn more about the Mixmaster Rehab Project here.

Prior to the rehab project, CTDOT engaged in a widening project to ease congestion on I-84. The I-84 Widening Project was completed in 2018 and has resulted in reduced congestion east of the Mixmaster. Learn more about the I-84 Widening Project here.

 

What is the New Mix?

The New Mix is an ongoing CTDOT program that will plan for and implement a series of projects to address the long-term needs of the Mixmaster interchange.

Does this mean that the Mixmaster will be replaced?

CTDOT, with public stakeholder input, will weigh both rehabilitation and replacement options in order to determine the best course of action for the future of the interchange.

How many cars travel on the Mixmaster?

The Mixmaster was designed to accommodate approximately 100,000 motor vehicle trips per day (predicted 1975 traffic volume). Currently, about 190,000 motor vehicle trips occur along the interchange each day. By 2045, this number is expected to approach 225,000 motor vehicle trips per day!

When is construction on the New Mix planned to begin?

Reconstruction of an interchange of this magnitude, whether through replacement or an intensive rehabilitation, requires a large amount of time and advanced planning in order to properly phase and fund the program.

Therefore, the New Mix program will likely be phased with breakout projects that will occur over a number of years.  Each set of breakout projects is intended to complement and work to advance the overall New Mix program through incremental improvements.  

The potential phasing of breakout projects is described below, along with anticipated construction dates for each.

Early Action Projects

Early Action Projects will generally focus on local road and intersection improvements with the intended goal of improving the function of the overall local road network without intensive construction or construction impacts. By improving the functioning of the local road network, Early Action Projects are also intended to improve the flow of traffic in the area. As Early Action Projects are smaller in scope, they may occur relatively soon, as early as the mid-2020s.

Near-term Projects

Near-term Projects will generally occur on the outer portions of the interchange and could include improvements to entrances, exits, and lane configurations that improve the function of the existing interchange approaches but are also aligned with the goals of the future improvements to the core of the interchange. Near-term Projects will also facilitate traffic handling during the eventual core interchange reconstruction. Some, but not all, Near-term Projects will require more extensive construction and may result in impacts to drivers. Near-term Projects may begin construction in the early 2030s, before the core of the interchange is reconstructed.

Long-term Projects

Long-term Projects include significant construction work that will be required to reconstruct the core of the interchange. Long-term Projects could include replacement or reconstruction of decks, the stacked bridges, and other elements of the interchange and connections between Interstate 84 and Route 8. Construction of Long-term Projects is anticipated to begin in the vicinity of the mid-2030s to the early 2040s. 

What is the National Environmental Policy Act (NEPA)?

The National Environmental Policy Act (NEPA) is federal legislation enacted in the late 1960’s that requires federal agencies evaluate the environmental impacts of their projects, including transportation projects, before they are formally implemented. NEPA also applies to any State projects that receive federal funding. The NEPA review typically begins just after the very early conceptual design process and includes the review of a range of design options.

What is the Planning and Environmental Linkages (PEL) Process?

Developed by the Federal Highway Administration (FHWA), the Planning and Environment Linkages process (PEL) considers and incorporates environmental, community, and economic goals in the very early planning and design phases of transportation projects. When PEL is used, it occurs concurrently with the early conceptual design process and NEPA occurs after PEL is complete.

When transportation projects are approached in this collaborative, multi-disciplined manner in the early planning phases, potential issues with design options are more likely to be discovered early on, and before the NEPA review.  Through the PEL process, these issues may be able to be resolved; if they cannot be resolved then those design options can be removed from consideration prior to the NEPA review.

The number of design options that are then considered during the NEPA review are both narrowed and more thoroughly vetted; therefore, the options are less likely to need to be revisited later as a result of NEPA requirements, saving both time and money.

Additionally, by including community and the economic development goals in the early planning phases of a given transportation program, PEL provides the opportunity for transportation projects to be designed in context with their environment and aligned with both community and economic development goals.

CTDOT intends to utilize the PEL approach for planning and advancing design concepts that will create a master plan vision for the New Mix.  Stakeholder groups, a Project Advisory Committee, and the general public will provide input on design and planning aspects of the project. Input and comments from all groups will be documented.

Why is the New Mix Program starting so early?

Reconstruction of an interchange of this magnitude, whether through replacement or an intensive rehabilitation, requires a large amount of time and advanced planning in order to properly phase and fund the program. Early Action and Near-term Projects, as described above, may begin to occur in the later 2020s and early 2030s, respectively.

Construction on the core of the interchange, as defined in Long-term Projects above, is not anticipated to begin for approximately 15 years. Prior to construction, there are many planning phases to be worked through, including defining a purpose and need for the project, evaluating design options, development of a final design, coordination with federal regulatory agencies, and securing necessary permitting.

Public involvement will be integral throughout the New Mix Program, including at this very early planning stage. Throughout the various planning phases for the New Mix, including PEL and NEPA which are described in FAQs above, CTDOT will provide regular updates, conduct public briefings, and invite public input.

Could continued rehabilitation of the Mixmaster be a cost-effective alternative to replacement?

Initial analysis has not indicated that good value can be achieved through continued rehabilitation of the Mixmaster. However, various rehabilitation and replacement alternatives will be examined more closely as part of the New Mix program’s early planning process. 

In 2018, CTDOT began to analyze whether yet another major rehabilitation project—to occur in 2045 and referred to as the 2045 Rehabilitation Analysis —would be a cost-effective way to further extend the Mixmaster’s lifespan and address functionality issues.

The 2045 Rehabilitation Analysis showed that despite a cost of approximately $1 billion (2017 dollars), another rehabilitation in 2045 would not substantially improve the interchange’s functionality, nor would it extend its lifespan significantly relative to the cost of a full replacement. There is a limit to how much the lifespan can be extended for the interchange’s steel support structures and for the decks upon which cars travel.

The 2045 Rehabilitation Analysis also found that continued rehabilitation would not be able to address operational and safety standards, which have evolved since the interchange was originally designed and constructed. These standards include roadway geometry (sight distance, sharpness of curves, and lane alignment), standard shoulders, spacing of interchanges and ramps, and left-hand entrances and exits.

In 2017 traffic volumes on the interchange stood at approximately 190,000 trips per day almost double the intended capacity of the system. By 2045, that number is expected to reach close to 225,000 vehicle trips per day. Planning for the safe maintenance of traffic flow during replacement of the stacked bridges presents another engineering challenge.

Through the New Mix Program various replacement and rehabilitation options will be considered, weighed, and analyzed against many factors including cost relative to lifespan, functionality, and safety.

How can I stay up to date on progress on the New Mix program?

There are many ways in which individuals can learn about, ask questions, stay up to date and provide input about the New Mix program.

Sign up for email updates here to receive the latest New Mix program news, notice of upcoming public meetings and more.

Additionally, you may leave comments or ask questions through the New Mix website anytime by clicking here. You can also follow us on Twitter at @NewMixWaterbury and on Facebook at @NewMixWaterbury