Frequently Asked Questions

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What is the Mobility35 Program?

Mobility35 is a regionwide effort to improve mobility and safety along I-35 in Williamson, Travis and Hays counties. Since 2011, the Texas Department of Transportation, the Capital Area Metropolitan Planning Organization, the city of Austin and other regional partners have been working on a plan for improvements to the I-35 corridor.

What is the purpose of the Mobility35 Program?

The purpose of the program is to transform I-35 into a smart and efficient highway. This effort will improve mobility and connectivity for all modes of transportation—cars, transit, trucks, emergency vehicles, pedestrians and bicycles — along and across I-35, as funding is identified.

What are the program limits?

The program limits include 79 miles of I-35 from the Williamson/Bell county line to the Hays/Comal county line.

Who is involved?

Mobility35 is a community-driven effort including local, state and federal agencies, as well as the public and community stakeholders throughout the three-county region. Current partnering agencies are listed on our partnerships webpage.

Why are I-35 improvements needed?

I-35 between US 290E and SH 71 is one of the most congested roadway in Texas. It serves as the backbone of the local, regional and national transportation network and has a much higher crash rate than the statewide average for urban interstates.

I-35 through Williamson, Travis and Hays counties was originally built more than 50 years ago. Improvements have not kept pace with population and economic growth, resulting in increased traffic congestion. Some segments in the Austin area carry more than 200,000 vehicles per day. As bad as highway congestion is now, it will only get worse as the area's population continues to grow.

How will the Mobility35 Program make I-35 better?

The Mobility35 program is transforming I-35 to be smarter and more efficient. Much like the way we communicate has evolved over the last 50 years, so should our transportation system. Consider the evolution of the phone from rotary to the 1980’s brick phone to our modern smart phones. Mobility35 will transform our old, outdated interstate system by doing the following:

  • Adding express lanes to provide a reliable route for drivers, buses, vanpools and emergency vehicles
  • Incorporating innovative designs, such as intersection bypass lanes, upgraded and innovative intersections, ramp modifications and integrated operations technology
  • Improving safety by increasing the distance that vehicles have to enter, exit and change lanes
  • Giving users the ability to make smart choices for how to travel along I-35, such as using express lanes, enhanced transit, or bicycle and pedestrian accommodations in addition to using traditional general purpose lanes
  • Providing users with up-to-date information using on-road technology to facilitate their decisions about where, when and how to travel
  • Reflecting community values by improving east/west connectivity, maximizing existing right of way without overbuilding, and allowing for technological advancement

What will happen if improvements to I-35 are not implemented?

Lack of mobility on I-35 threatens the economic livelihood of our cities and our state. I-35 between US 290E and SH 71 is one of the most congested roadway in Texas. Today, this area is congested for six hours a day. If nothing is done, by 2040, it is estimated to be congested for nine hours a day.

Not only is traffic congestion inconvenient, it negatively impacts our quality of life and creates other issues, such as:

  • Safety: More than 4,950 crashes occurred on I-35 in Central Texas in 2015, and 24 involved fatalities. I-35 through Austin has a higher crash rate than the state average.
  • Emissions: Idling vehicles stuck in traffic emit more air pollutants.
  • Emergency response: Traffic congestion creates delays for emergency response vehicles carrying patients to and from 29 hospitals and other health-care facilities located within approximately 2 miles of the I-35 corridor.
  • Economy: Traffic congestion is unattractive to businesses. Travel delays drive up the cost of goods and negatively impact the quality of life for everyone sitting in traffic.
  • Transit delays: Traffic congestion creates delays for public transit buses and registered vanpools, diminishing reliability and discouraging people from using alternate forms of transportation.

We can expect our traffic congestion problems to worsen as our population grows. Over 2 million people live in the Austin area today, and over 3.8 million are expected to live here by 2040.

Who is using I-35?

Despite being an interstate, most of the traffic on I-35 is caused by local drivers making local trips to and from home, school, work, and other destinations in Central Texas. Daily volumes on I-35 exceed 200,000 vehicles—86 percent of these vehicles have an origin or destination in Williamson, Travis or Hays counties.

Travelers of I-35 include local and through-traffic, commuters, cross street traffic, transit customers, carpoolers, bicyclists, and pedestrians. Because of the wide array of transportation modes in this corridor, the Mobility35 Program is focusing on effectively moving people along and across the interstate.

Why haven't prior solutions from other plans been implemented?

Previous studies to improve I-35 have focused almost exclusively on large-scale traditional construction projects to address the current and future needs along the corridor. Unfortunately, many of these large-scale projects were determined to be extremely costly and difficult to implement due to the extensive right-of-way acquisitions, construction time required and potential impacts on the community. As a result, they have not advanced toward implementation.

What kind of improvements can we expect in the future?

Since 2011, TxDOT has been working with its partners to develop a program that reflects community values that have been shared with us over the last few years. The proposed improvements are smart, efficient and will provide options that let users decide when, where and how to travel.

The Mobility35 Program comprises individual improvement projects up and down I-35 that collectively provide substantial benefits for congestion relief. The goal is to improve mobility along and across I-35 without wholesale reconstruction of the corridor.

The program focuses on innovative solutions to optimize the current facilities and right of way. Improvements will include:

  • Intersection improvements, including innovative intersection designs (e.g., diverging diamond intersections, roundabouts and median U-turn intersections)
  • Ramp reversals
  • Modified frontage roads
  • Intersection bypass lanes
  • Operational improvements
  • Bridge reconstruction
  • Traffic Management Systems upgraded to incorporate the latest technologies that provides I-35 users with information they need to make smart travel decisions
  • Bicycle and pedestrian accommodations

What are operational improvements?

Operational improvements are enhancements or changes to the roadway that do not add capacity but still contribute to improved traffic flow and efficiency. Some examples of operational improvements include intersection bypass lanes, upgraded and innovative intersections, ramp reversals, increasing entrance and exit lane lengths, and integrated technology.

How do operational improvements help improve traffic flow?

Operational improvements add value to the existing transportation network by making the roadway system more efficient, alleviating traffic congestion and improving safety. For the Mobility35 Program, this all occurs while staying within or maximizing current right of way. Implementing multiple operational improvements throughout the corridor can substantially reduce travel time and delay. Some examples of operational improvements already constructed that are improving travel times include the diverging diamond intersection at I-35 and RM 1431 in Round Rock and the northbound intersection bypass lane at Parmer Lane.

What lane capacity improvements are proposed?

The proposed improvements include adding more lane capacity along the entire corridor. TxDOT is working with local area partners, including Capital Metro, to study the impact of adding express lanes along I-35 in Williamson, Travis and Hays counties.

Over the course of the recently launched North16, Central7 and South10 corridor studies in Travis County, potential environmental impacts will be evaluated and mobility alternatives will be developed that take into account the needs of drivers, transit riders, bicyclists and pedestrians, as well as surrounding neighborhoods and businesses. The first public meetings for these projects began in early summer 2016. Public feedback and input throughout the studies will be important to ensure the projects reflect community values.

What are express lanes?

Express lanes are special toll lanes that will be separated from the existing non-tolled lanes. Express lanes provide public transit buses, registered vanpools and emergency vehicles with a reliable, toll-free route to their destination. Travelers willing to pay a toll also experience the same reliable route.

To keep the express lanes from becoming congested, individual drivers are charged a variable toll that increases when traffic is heavy and decreases when traffic is light. The primary goal is to keep the express lanes free-flowing as much as possible. Individual drivers will have to decide whether any particular trip is worth the toll being charged for a reliable travel time.

How do variable tolls work?

To ensure the express lanes remain free-flowing, variable tolls are used to manage the number of vehicles entering the 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. Changeable electronic signs display the current rates in real time, so drivers know the price before deciding whether to enter the lanes. Once you are in the express lanes, the price you saw on the signs is the price you are guaranteed to pay.

How will the improvements benefit users choosing not to use the express lanes?

The proposed improvements will benefit all I-35 users, including those traveling in the non-tolled, general purpose lanes or by bus, bicycle or foot.

Express lane users can likely count on a reliable trip, but all users benefit. Traffic studies and comparable projects, including the Dallas/Fort Worth area express lanes, show faster travel speeds in the general purpose lanes with the completion of the express lanes. Also, the projects include the construction of north/south shared use paths, sidewalks and bicycle lanes, as well as sidewalks and bicycle lanes at east/west connections that otherwise would not have been built, allowing for safer mobility for bicyclists and pedestrians.

Isn’t tolling just another tax?

No. Tolling is a voluntary fee paid by users for a service when they need it. Paying taxes is not a choice. Drivers have the option to pay tolls or take alternate routes while taxes are mandatory and charged to everyone.

Without the ability to use tolling as a funding source, local and state agencies must rely on existing or increased tax-funded sources. Gas tax as a funding source has remained static since 1991, even though fuel costs have risen.

Why aren't we adding more general purpose lanes/HOV/rail to I-35?

The goals and objectives of the Mobility35 Program include optimizing the existing I-35 facility while minimizing the need for additional right of way. This community-driven approach differs from previous studies to improve I-35, which focused almost exclusively on large-scale traditional construction projects. Many of these large-scale projects were determined to be extremely costly and difficult to implement due to the extensive right-of-way acquisition needed, construction time required, and potential impacts to the community. As a result, they did not advance toward implementation.

In 2013, the Travis County Mobility35 Corridor Implementation Plan was released, which identified a number of potential mobility solutions for the I-35 corridor, including the Future Transportation Corridor, which was identified as an area for additional capacity down the center of I-35. This improvement would provide the single largest capacity gain for I-35.

A Planning and Environmental Linkages (PEL) Study was conducted in 2014 to help determine the purpose and need for the additional capacity, lane type alternatives/mode choice, and segments of independent utility (stand-alone projects) in Travis County.

The purpose and need included improving operational efficiency, managing congestion, providing more reliable travel times, and creating a more dependable and consistent route for transit, emergency responders, and other motorists.

There were nine potential lane type alternatives/mode choices studied:

  • General purpose lanes
  • High occupancy vehicle lanes with transit
  • Express lanes with transit
  • Express lanes with enhanced transit access
  • Rail
  • Through-traffic only lanes
  • Transit-only lanes
  • Freight-only lanes
  • No build or doing nothing

These lane type alternatives were evaluated against the purpose and need of the PEL study, resulting in a recommendation that two express lane alternatives be further evaluated in future National Environmental Policy Act (NEPA) studies: an express lane with transit and an express lane with enhanced transit access. However, since transit plays an integral role in providing an effective travel option for I-35, we determined we should study options to allow Capital Metro the ability to construct structures that provide direct transit access into the express lanes in the future. Consequently, each build alternative for the additional capacity includes direct transit access to the express lanes. Public outreach continues to play a vital role in the development and refinement of the alternatives.

Finally, the three stand-alone express lane project limits were determined to be:

General purpose lanes, HOV, rail and other lane type alternatives/mode choices did not advance because they did not provide the same reliability benefits for all I-35 users, including transit, emergency responders and drivers.

How are the projects being funded?

To date, funding has not been identified for all of the projects included in the Mobility35 Program. Funding sources could include federal, state, local or private dollars. The needed mobility and safety improvements along I-35 are estimated to cost:

  • Williamson County: $0.7 billion to $0.8 billion
  • Travis County: $2 billion to $2.4 billion (dependent on final downtown Austin option)
  • Hays County: $1.5 billion

Current projects are being funded by a mix of voter-approved Proposition 1 funds, Congestion Relief Initiative funds, state gas tax funds and local investments.

What is the schedule and when will improvements happen?

The Mobility35 Program designates where and when over 40 projects on I-35 could be built if funding is identified. Several projects currently have funding and construction has begun.

Construction along the corridor is expected to be ongoing for the next 10 to 15 years. The majority of the projects are unfunded, but they remain a priority to the region. We will continue to work with our transportation partners and the community to design, develop and construct these projects. For the most up-to-date information, visit the Capital Region webpage.

How are projects prioritized?

A number of factors are considered when deciding when and how a project moves into the environmental, development or construction phase. When funding becomes available, the program team takes into consideration what phase the project is in, whether additional right of way will be needed, whether enough funds are available to complete the project, and the impact of the safety and mobility benefits. These considerations determine the order in which a projects advances.

What concepts are being considered for the downtown Austin section of I-35?

Through downtown, the proposed improvements include adding express lanes and intersection bypass lanes, ramp modifications, frontage road improvements, improvements to east/west mobility, and bicycle and pedestrian accommodations.

In addition, two geometric options for incorporating mobility improvements in the downtown section of I-35 are being studied. Developed over two years with extensive public and stakeholder outreach, each option presents the same improvements in mobility using different roadway configurations. "Mobility improvements" is a blanket term for improvements that actually contribute to the function of the roadway and traffic movement. Options for the section of I-35 from 8th Street to Cesar Chavez Street includes:

  • Raised option: Proposed improvements would replace and improve the current mainlanes in a similar configuration as it is today, meaning the mainlanes would go over the east/west cross-streets. At Cesar Chavez Street, the southbound mainlanes would be rebuilt to go over Cesar Chavez Street similar to the northbound side.
  • Lowered option: Proposed improvements would involve lowering both northbound and southbound I-35 mainlanes below current ground level to go under the east/west cross-streets from 8th Street to Cesar Chavez Street.

How can a change in travel behavior improve mobility on I-35?

We all know that it's going to take everything, including the kitchen sink, to manage congestion on I-35. This includes changing the way we get to and from work. TxDOT is contributing to changing driver behavior with the launch of their WorkWise employee work-trip reduction program. WorkWise gives TxDOT employees work options, such as teleworking, compressed work weeks and flexible schedules, as well as encourages employees to carpool, vanpool, ride transit, and use bicycle and pedestrian accommodations. We must all continue to work together to change travel behaviors in order to reduce the number of cars on I-35.

What is a Traffic Management System?

In effort to transform I-35 into a smart and efficient highway system, we are upgrading our Traffic Management System in the Austin District. The Traffic Management System uses technology to provide I-35 users with information they need to make smart travel decisions and stay safe on the road. TxDOT is adding cameras and large dynamic message signs along I-35 in Williamson, Travis and Hays counties, as well as other major roadways in the area like US 183, US 290, SH 71, etc. By gathering and disseminating reliable information about what’s happening on our roads throughout the day, users will be able to plan their routes based on future traffic patterns and be alerted about lane closures and alternate travel times if they take an express lane or general purpose lane. Activities are currently underway for this initiative and should be complete in 2018.

The program also includes the continuation of the Highway Emergency Response Operator, or HERO, safety patrol truck program. HERO is a free roadside assistance program for stranded motorists that helps keep traffic moving.

How do you plan to address additional noise?

A noise analysis will be conducted as part of the environmental studies required before construction can begin. The analysis considers the current level of noise at many locations throughout the study area, calculates existing and projected future traffic noise levels, and considers noise reduction measures if the predicted future noise levels exceed acceptable levels for properties that surround the project. The results of that analysis will be made available at future public meetings and will be included as part of the environmental study.

Why can't we just move all the trucks to SH 130?

A 2013 report by the Texas A&M Transportation Institute entitled, "Establishing Mobility Investment Priorities Under TxDOT Rider 42: Long-term Central Texas IH-35 Improvement Scenarios," found that attempts to re-route truck traffic from I-35 to SH 130 would have limited impact on I-35 congestion. The report cited two reasons for this.

First, much of the truck traffic has an origin or destination near the corridor, making I-35 a desirable or necessary route. Second, truck drivers traveling through the Austin area without stops generally find I-35 is the most efficient route for their delivery schedule. The report recommended a hybrid approach to solving congestion on I-35 including added capacity, shifting commuter trips to work-at-home jobs, using technology to reduce trips, shifting trips to off-peak periods and increasing alternatives to single occupancy vehicle usage.

It is also important to note that removing tolls from SH 130 would not be free. Investors who contributed private money to pay for the accelerated design and construction would have to be repaid, and that cost would have to be weighed against the cost of improving I-35.

How can I provide feedback?

The project team continues to take comments from the public. Individual projects will have public events where stakeholders will be able to review proposed improvements, speak with the project team, and submit comments. More information can be found through the Capital Region webpage.