Section 4: Corridor Studies

Corridor Studies Process

Corridor studies are typically conducted along an elongated area that spans across multiple counties, cities/towns, and TxDOT districts. Such areas are likely to include multiple transportation modes, including vehicles, railroad, transit, aviation, maritime, bicycle and pedestrian, and a mix of land uses. The corridor should be large enough in length and width to accommodate design alternatives. Corridors are of strategic importance to TxDOT and the communities adjacent to the corridor, such as an interstate highway, hurricane evacuation route, or part of the freight highway network. Other data such as vehicle crash information, traffic projections, pavement condition, and outdated roadway design may also warrant a study to be conducted.
The purpose of a corridor study is to assess existing and forecasted conditions along the highway corridor and develop an implementation plan of prioritized projects based on need and when they should occur [short (0-4 years), middle (5-10 years) and long term (10+ years) timeframes]. From the implementation plan, the TxDOT District(s) can then begin the process of planning and programming these projects into their respective project portfolios for further study and funding. However, there is no guarantee that after the study that any and all identified potential projects would be funded, implemented or implemented in the timeframes recommended in the corridor study.
Alternatives for transportation improvements can vary along a corridor and may include, but are not limited to, constructing new main lanes and/or frontage roads, limiting access, constructing grade separations, changing vehicle clearance height at bridges and overpasses, changing frontage road orientation from two-way to one-way, and changing overpass and interchange configuration (“reversing the stacks”). Transportation system management components such as traffic signal optimization, intersection improvements and intelligent vehicle/highway system elements may also be appropriate solutions. Corridor studies may include consideration of high-occupancy vehicle lanes, high-occupancy/toll lanes, tolled facilities or managed lanes as alternatives.

Collection of Information for the Corridor Study

TxDOT will use available data as applicable to conduct the study. This includes but not limited to:
  • feasibility and/or route studies,
  • environmental data and documentation,
  • TxDOT District Plans (examples: snow and ice removal, transportation system management),
  • maps,
  • geographic information system (GIS) files,
  • vehicle crash data,
  • as-built plans,
  • traffic data (historical and projected volumes for trucks and cars),
  • Bridge Inventory, Inspection, and Appraisal Program (BRINSAP) data,
  • Light Detection and Ranging (LiDAR) data, and
  • other documents which are applicable as background information for the corridor study
Data is also obtained from literature searches and purchase of materials such as GIS databases and land use plans from other entities such as government agencies (federal, state, regional, local), and private organizations. Counting traffic may be needed to augment traffic data that TxDOT has. Driving along the existing highway corridor and adjacent public roads in the study area can provide additional context and possible identification of land uses and environmental features that were not identified during the literature search. There is no need to access private property during a corridor study.

Corridor Study Contents

A corridor study may include the preparation of:
  • Maps and graphics, such as study area limits, environmental features, and conceptual plans
  • Typical section(s) (rural and/or urban, with and without frontage roads)
  • Summaries of meetings with a stakeholder working group, TxDOT personnel, individuals/groups, etc.
  • Technical memoranda
    • traffic analysis (methodology, existing and projected conditions; crash frequency)
    • engineering considerations, including design criteria, typical section(s), route option evaluation, preliminary cost estimates (construction, right-of-way acquisition, utility adjustments)
    • other subject matter as warranted
  • Corridor study report prepared using the information above and including:
    • Background information, including study area description and information from previously conducted feasibility studies
    • Purpose and need
    • Inventory of existing transportation system features, modes, operating conditions and safety issues
    • Correspondence/Resolutions from cities, counties and planning organizations (Metropolitan Planning Organization, Rural Planning Organization) supporting the conduct of the corridor study
    • Environmental features and land use [including, but not limited to natural resources, water resources, community facilities such as parks, schools, first responder facilities, air quality status (attainment, non-attainment), future land use]
    • Descriptions of the alternatives development and evaluation process
    • Implementation Plan of prioritized projects
    • Summary of stakeholder working group/citizen committee meeting(s)
    • Other findings and recommendations that are of importance

Soliciting Comments on the Corridor Study

Early identification of issues of concern as well as opportunities in a corridor study will help guide the development of alternatives that can be supported by local constituencies. Given the generally longer length of a highway corridor being studied (some corridors previously studied have been over 100 miles long) and the multiple jurisdictions that a corridor can cross, TxDOT will typically form a stakeholder working group comprised of elected officials, business representatives, agencies, and private citizens representing a wide variety of interests along the length of the corridor. The working group is typically led by a chairperson such as an elected official, who collaborates with TxDOT to identify potential group members to invite to participate in the study. TxDOT and the working group chairperson collaborate on study goals, facilitate meeting agendas and logistics and encourage group participation in sharing information and identifying issues and opportunities. Recommendations from the working group will be taken under consideration by TxDOT, who will ultimately be responsible for implementation.
Other tools and methods that TxDOT uses to inform interested parties include, but are not limited to:
  • Study information on TxDOT’s website txdot.gov;
  • Fact sheets;
  • Individual meetings with groups, citizens, elected officials, agencies, etc.; and
  • TxDOT points of contact at the TPP Division-Corridor Planning and the local TxDOT District office(s) where the study is occurring.
Public meetings are generally not effective as a means of soliciting comments for a high-level planning study such as a corridor study. Alternatives are generally developed at a conceptual level and may not be developed to such a level of detail as to promote interest from communities where the highway corridor is being studied. Depending on the length of the corridor and the number of communities along it, sustaining multiple rounds of public meetings would likely require an extensive amount of time and resources from TxDOT to conduct, with no guarantee of robust interest from the public.

Corridor Study Approval

Approval that a corridor study has been successfully completed resides with both the local TxDOT District office and the TPP Division-Corridor Planning. Approval will occur with the acceptance of study deliverables as identified in a scope of work, whether that is prepared by TxDOT or a consultant. If a citizen committee that has been involved with a corridor study, TxDOT may request concurrence that the study has been completed to its satisfaction.
Corridor study approval by District offices and the TPP Division does not commit TxDOT or the Texas Transportation Commission to implement all recommendations noted in the final corridor study report and implementation plan. It does not commit TxDOT and the Texas Transportation Commission to program funds for any subsequent phases of project development.