Southwest Washington Regional Transportation Council

Transportation Corridor Visioning Study


Clark County’s rapid population growth is quickly outpacing the capacity of its transportation infrastructure. The need to provide for transportation mobility between growing, outlying areas of the county and the increasing travel demand between Oregon and Southwest Washington demonstrate the need to identify and plan for potential new, regional transportation corridors within the county, as well as across the Columbia River.


The Transportation Corridors Visioning Study was an effort to identify and assess potential new regional transportation corridors in Clark County and across the Columbia River. The purpose of the Visioning Study was to begin to answer the question: “How would we get around within our own community in the longer-term future if our County reaches one million in population?” The intent of the study was to provide a high-level “50,000-foot level” planning analysis while future phases may assess land use implications and evaluate corridors at a higher level of detail.


A Steering Committee comprised of elected and appointed officials from agency members of the Regional Transportation Council provided policy input on the study, with technical assistance from agency staff from those jurisdictions. The Visioning Study project team was comprised of RTC and consultant staff.


The study report (37pp, 1.93mb PDF) was intended to be exploratory and informational. It summarizes the process and outcomes of the first phase of the study which identified a set of candidate corridors that could provide regional mobility. Future phases of the Visioning effort may continue to focus on the land use and transportation implications of new corridors, eventually taking action on whether to add one or more corridors to the Metropolitan Transportation Plan.

Transportation Corridor Visioning Study, Final Report

Main Report Body, 1.93MB

Appendix A: Land Use Assumptions, 5.41MB

Appendix B: Travel Forecasting Summary and Volumes, 2.33MB

Appendix C: Land Use Think Tank Workshop Presentation, 3.01MB

Appendix D: Corridor Definition, Assessment, and Performance Measures, 395KB

Appendix E: Analysis of New Crossing(s) of the Columbia River, 399KB

Appendix F: Transportation Think Tank Presentation, 1.75MB

Appendix G: Corridor Preservation Memorandum, 38KB

Appendix H: Steering Committee Meeting Agendas and Notes, 4.25MB

Appendix I: Other Background Research and Technical Memos, 1.47MB

Appendix J: Public Outreach and Comment, 268KB

Appendix K: Land Use Think Tank Workshop #2, 6.22MB

Appendix L: Presentations of the Draft Study Report, 10KB


The Visioning Study resulted in several key findings. The land use assessment indicated that, based on existing policies and urban growth areas, Clark County will tend to grow outward with some densification in already-established urban and rural centers, and a continued growth in cross-Columbia River trip-making. Additionally, the travel demand from these growth patterns will show a mix of regional and sub-regional trip-making, indicating a need for new, sub-regional corridors to accommodate shorter trips in addition to the regional corridors. The Visioning Study also examined potential strategies for corridor preservation, most of which require inclusion of new corridors on an adopted local Comprehensive Plan as well as the Metropolitan Transportation Plan.

Candidate New Regional Corridors Map

The Visioning Study culminated with a map showing several potential regional corridors within Clark County as well as potential new crossings of the Columbia River.

Vision Plan: Candidate New Regional Corridors Map

A high-resolution version of the Candidate New Regional Corridors Map (582kb PDF) is also available.