The MoPac South Environmental Study is thoroughly analyzing the MoPac Expressway from Cesar Chavez Street to Slaughter Lane to determine the best option for improving mobility and safety. This study has identified a full range of alternatives, and through extensive analysis and community outreach, identified the Express Lanes(s) Alternative as the Reasonable Build Alternative. In November 2015, the project team identified six potential express lane(s) operational configuration options. Those options are being further evaluated to determine which should move forward, and were shared again most recently at open house #5 for public review and comment. 

This process and its results will be fully documented in an Environmental Assessment per the National Environmental Policy Act of 1969 (NEPA). The No-Build, or “do nothing,” Alternative continues to be carried forward as a baseline for comparison and an option for approval.

In February 2015, after extensive analysis of the engineering feasibility, social, economic and environmental impacts of each alternative, as well as consideration of public input, the study team recommended that the Express Lane(s) Alternative move forward for further evaluation.

In November 2015, through additional evaluation, the project team shared six different potential express lane(s) operational configuration options with the public. These will be further evaluated to determine which option should move forward. 

In 2016, the study was put on a temporary hold due to a lawsuit and to allow time for transportation agencies to discuss how best to fund transportation needs in the state.

In 2021, the study team resumed reviewing and carrying forward the work done and decisions made in 2015 to identify an express lane(s) operational configuration option that meets the purpose and need of the study. 

An open house was held in late 2021/early 2022 to reintroduce to the six express lane(s) operational configuration options for downtown connectivity and solicit public comment. Additional public comment opportunities will be available in the future. 

• Current congestion levels are creating unreliable travel times
• Existing and forecasted population, traffic, and employment growth create increased congestion and delay
• Emergency response times are impacted by traffic congestion

If we do nothing to address congestion, drivers could spend an additional 35 minutes traveling the corridor by 2035.

The Central Texas Regional Mobility Authority (Mobility Authority) and the Texas Department of Transportation (TxDOT) are developing the MoPac South Environmental Study cooperatively with other local partners. 

The study area is an approximately 8-mile segment of MoPac Expressway from Cesar Chavez Street to Slaughter Lane.

The preliminary alternatives included:

• Add General Purpose Lane(s)in each direction
• Add High Occupancy Vehicle (HOV) Lane(s)in each direction
• Add Transit Only Lane(s)in each direction
• Add Express Lane(s)in each direction
• Transportation Systems Management (TSM) / Transportation Demand Management (TDM) TSM is a collection of low-cost (non-capital intensive) strategies to enhance safety, reduce congestion and improve traffic flow; TDM is managing or decreasing the demand for auto-related travel by using a variety of measures to increase the operating efficiency of transportation facilities.
• No-Build, or “do nothing” alternative

Based on initial evaluation, the Express Lane(s) Alternative, along with the HOV Lanes Alternative and the Transit Only Lanes Alternative were carried forward for further study because each met the Purpose and Need for the project.

Following analysis of each of the alternatives recommended for further study using the Goals and Objectives for the project and other criteria, the project team determined that the reasonable build alternative to be studied going forward is the Express Lane(s) Alternative. 

The No Build alternative continues to be carried forward as a baseline for comparison and an option for approval. Under this scenario, routine maintenance of the corridor would continue. This alternative also assumes any other improvements/strategies in the Capital Area Metropolitan Planning Organization’s Long Range Transportation Plan would move forward.

Express lanes are special lanes separated from the non-tolled general-purpose lanes. The purpose is to improve commutes by managing congestion. This is accomplished through variable toll pricing, which either encourages or discourages use by increasing the toll when traffic is heavy, and decreasing the toll when traffic is light.

The primary goal of express lanes is to keep traffic in the lane free-flowing for individual drivers and transit riders. This ensures a reliable, non-stop route is available to drivers wishing to bypass congestion for the price of the toll. Public transit buses, registered vanpools and emergency first responders travel these lanes toll-free. Learn more here.

Variable toll pricing is used to manage the number of vehicles using express lanes at any given time. When traffic is heavy and demand for the express lanes is high, toll rates increase. When demand is low, toll rates go down.

• To keep the express lanes from becoming congested, individual drivers are charged a variable toll to manage the number of vehicles entering the express lanes at any given time
• When traffic is heavy and demand for the express lanes is high, toll rates increase. When demand is low, toll rates go down
• Electronic signs display the current rates, so drivers know the price before deciding whether to enter the express lanes
• Express lanes are toll-exempt for public transit buses, registered vanpools, and emergency first responders
• The primary goal is to keep the express lanes free flowing as much as possible

Adding one general-purpose lane and one express lane in each direction instead of adding two express lanes in each direction would reduce the capacity and operational efficiency of the proposed express lane(s), without adding appreciable improvement in speed or reduction in delay on the general-purpose lanes.

If another general-purpose lane was added to the corridor, it would fill up with traffic just like the existing MoPac. Even adding two general-purpose lanes in each direction would not address congestion issues on the corridor during the morning and evening peak periods in 2035. Adding one general-purpose lane would have even less impact on average speeds.

After the initial review of the Express Lane(s) Alternative, the project team developed six potential express lane(s) operational configuration options for consideration by the project team, transportation partners and the community. Next, the project will identify the best option following additional public input opportunities.

When an express lane(s) operational configuration option is selected, the study team will complete the draft Environmental Assessment. This document identifies the Recommended Build Alternative, demonstrates an analysis of the alternatives considered, and presents an assessment of potential impacts to the human and natural environment. When complete, this draft document will be presented at a public hearing for input. With support from its partners, the Mobility Authority will make a final recommendation to TxDOT for their review.

Project design variations built upon the Express Lane(s) Alternative design. These are intended to provide additional design possibilities related to access points, ramp placement, downtown connectivity, interchange layout, intersection configuration and lane balancing.

Six different options were reviewed and analyzed. You can view information about each of them here 

If the study's Reasonable Build Alternative of Express Lane(s) moves forward, the improvements would be tolled.

Potential impacts to the following will be considered:

• Endangered species and wildlife
• Barton Creek Greenbelt and Barton Springs
• Edwards Aquifer Recharge Zone and water quality
• Water resources, wetlands, floodplains
• Vegetation
• Cultural resources
• Traffic noise
• Air quality
• Socio-economic issues, including community cohesion
• Geology and soils
• Visual and aesthetic qualities
• Parkland
• Bicycle and pedestrian facilities

The study will assess the direct and indirect impacts of proposed transportation improvements to the environment. Potential direct and indirect impacts will also be analyzed cumulatively, together with the effect resulting from other past, present and future actions. 

Direct Impacts caused by a roadway improvement could include commercial and residential displacements, impacts to waters of the U.S. including wetlands, or impacts to historical properties.  Such impacts occur at the same time and in the same location the improvement is implemented.

Indirect Impacts caused by a roadway improvement could include growth inducing effects and other effects related to changes in the pattern of land use, population density or growth rate as a result of the project.  While not directly impacting a resource, indirect impacts could still manifest in such areas as air quality, water quality, or habitat values.  Such impacts, while reasonably foreseeable, are farther removed in distance from the improvement or occur later in time.

Cumulative Impacts are focused on the incremental impacts of the roadway improvement when combined with other past, present and reasonably foreseeable future actions.  Cumulative Impacts may be the result of projects or activities implemented by other entities. For example, potential cumulative impacts on water quality may stem from infrastructure improvements implemented by public agencies combined with land development activities initiated by private entities, as well as any direct and indirect impacts generated by the proposed action.

Yes, bicycle and pedestrian facilities are being considered as part of the study process. The Express Lane(s) Alternative would include significant bicycle and pedestrian improvements. The project proposes an ADA-compliant shared use path along the corridor that connects with existing and other planned bicycle and pedestrian facilities, resulting in an 8-mile, continuous facility for bicycle and pedestrian travel from Slaughter Lane to Lady Bird Lake. Proposed improvements also include construction of ADA-compliant sidewalks where feasible within the TxDOT right-of-way, including along cross streets. This provision allows the project to link to the existing City of Austin sidewalk network along the east and west sides of the corridor.

The segment of MoPac under study is within the Edwards Aquifer recharge zone, a 1,250 square mile area that allows large quantities of water to flow into the Aquifer through highly porous limestone. Because of this, the project would include the preparation of, and compliance to, a Water Pollution Abatement Plan for approval by the Texas Commission on Environmental Quality (TCEQ). Additionally, any new impervious cover over the Recharge Zone must meet the Edwards Aquifer rules for the removal of Total Suspended Solids (TSS) from storm water runoff. TSS is a water quality measurement used to describe the concentration of pollutants in water runoff.

Through the implementation of TCEQ's Edwards Aquifer rules, the project would utilize existing and new water quality structures and other Best Management Practices (BMPs) to remove at least 80% of TSS from the roadway storm water runoff prior to its release into the surrounding ecosystem. The project would consider upgrading or replacing existing water quality structures as well as the use of permeable pavement, vegetated filter strips, and construction of new water quality ponds to achieve this level of TSS removal.

If the project is environmentally cleared, a Stormwater Pollution Prevention Plan (SWPPP) will be developed to describe all of the stormwater management plans and BMPs to be included in the project. The SWPPP will include a description of the emergency procedures to be used in the event of a hazardous spill during construction, as well as other construction-phase protections, including the use of sediment curtains to contain any disturbed sediment and prevent sediment displacement.

Even if funding was available to construct general-purpose lanes, latent traffic demand, or drivers who currently use other routes to avoid MoPac South congestion, would quickly fill these lanes, and they would become congested like the existing general-purpose lanes on MoPac. The approach to solving congestion by simply adding multiple lanes of pavement is not sustainable and has not proven to be effective in managing traffic and promoting transit. Express lanes are being implemented around Texas and other states to manage congestion rather than patching the problem just to face the same challenges in a few years.

The majority of additional structures proposed for this project would match the elevation of the current MoPac structures.

The Mobility Authority arranged for an independent traffic study to evaluate the impact that the express lanes would have not only on Cesar Chavez Street; and the traffic near Austin High, but on the rest of the surrounding downtown street grid. The study showed that the project would not adversely affect congestion on Austin's downtown street grid as a whole. For more information on the traffic study, view this research brief. 

Adding express lane(s) to MoPac South would be a significant improvement for transit, specifically bus transportation. The Mobility Authority's policy allows public transit buses such as Capital Metro to drive on the express lanes without paying a toll. Because the variable-priced toll in the express lanes would be set at a rate intended to maintain uncongested traffic flow, transit riders would be ensured a reliable trip, even during peak periods, which will make riding transit a viable alternative to driving alone. The team is also working to identify appropriate locations for Park & Rides.

Public participation and input are critical to the study. We are committed to collaborative and transparent public involvement throughout the decision-making process.

Corridor residents, businesses, roadway users, local agencies, the general public and other interested parties can obtain information about the project in many ways, such as:

• Visiting us online at www.MoPacSouth.com
• Contacting the study team using an electronic submission form on the website or by phone at 512-342-3299
• Signing up for electronic newsletters
• Attending open houses, the public hearing and other public activities that will be conducted throughout the environmental study process
• Requesting a meeting or presentation