Supervisor talks with employee in front of computer.

Challenges associated with assessing the indirect and cumulative effects of transportation projects across Texas have been eased by a revised and simplified set of handbooks and guidance documents developed by the Texas Department of Transportation (TxDOT).

TxDOT faces a distinctive challenge when assessing the indirect and cumulative effects of its projects across the state: the state lacks a statewide land use management policy and manages its lands at the local level. The lack of a statewide approach to land use creates varying conditions across the state that make a strictly defined indirect and cumulative effects process unfeasible—the same project could have drastically different indirect and/or cumulative effects under contrasting land use conditions created by the various land use policies of different cities.

For example, where one city may employ strict zoning laws, other cities may frequently and broadly grant variances; an interchange project that may reasonably be assumed to have a ½-mile radius Area of Influence (AOI) in the first city may require an AOI with a radius of several miles in the second city because the second city’s less strict zoning creates the possibility of a geographically much larger AOI.

The varying land use climates across the state and extensive use of frontage roads parallel to limited access facilities create an interesting challenge for Texas: how to create guidance that balances streamlining the indirect and cumulative effect analyses with the unique conditions presented by different local approaches to land use regulations.

TxDOT’s indirect and cumulative impacts guidance helps streamline implementation of projects such as the FM 2493 Road Widening EA Project in Smith County, Texas. Photo: Texas Department of Transportation

Developing the Guidance

The Council on Environmental Quality (CEQ)’s guidelines for National Environmental Policy Act (NEPA) implementation (40 CFR §§1500-1508) established the requirement for federal agencies to consider direct, indirect, and cumulative impacts in the NEPA process. Subsequent guidance and resources provide further direction on considering indirect and cumulative effects under NEPA (e.g., AASHTO Handbook 12NCHRP Report 466FHWA Interim Guidance and Q & A, and NCHRP Project 25-25, Task 43).

TxDOT developed its own cumulative impacts guidance in the early 2000s, which was met with positive feedback from around the state and other DOTs. Soon after, the agency began developing a guidance that incorporated both indirect and cumulative impacts. Following the suggestion of FHWA Texas Division, the more comprehensive guidance document pulled from a variety of sources like the NCHRP Report 466—the Transportation Research Board’s Desk Reference for Estimating the Indirect Effects of Proposed Transportation Projects—to provide TxDOT project teams with a step-by-step process. Initially implemented in 2009, minor updates to the guidance document in 2010 added keys for success and how to approach small projects through added-capacity Categorical Exclusions.

Implementing the 132-page guidance document proved both successful and challenging. The guide acts as a detailed “how-to” resource of indirect and cumulative impact analysis methods. TxDOT learned, however, that document users found its size cumbersome and struggled with the unfamiliar technical terms (e.g., notable feature, impact-causing). In response, TxDOT split the guidance into two separate guidance documents—one for indirect effects and one for cumulative effects—and simplified them by consolidating the number of steps, removing technical jargon, and splitting out easily convoluted concepts, such as growth-related effects and encroachment effects. TxDOT also added an Indirect and Cumulative Impacts Handbook to provide a high level overview of the steps to conduct a thorough and defensible analyses of indirect and/or cumulative impacts that may occur as a result of a transportation project.

Nicolle Kord, TxDOT’s indirect and cumulative impacts expert, said the agency has “attempted to structure our guidance to be more accessible to a wider audience; in particular for those new to indirect and cumulative impact analysis.” For example, she said, TxDOT “attempted to make these complex ideas easier to understand by breaking them up into their individual parts (indirect encroachment impacts, indirect induced growth impacts, and cumulative impacts) as well as by removing jargon and putting guidance in plain language.”

Key Features of the Guidance Documents

The following table illustrates several key features of TxDOT’s indirect and cumulative effects guidance documents that contribute to their efficacy.

Indirect and Cumulative Impacts Handbook (2014) Indirect Impacts Analysis Guidance (2015) Cumulative Impacts Analysis Guidelines (2014)
Policy justification and regulatory overview.

Includes 4 possible compliance paths for a project.

Framework

Establishes policy requirements, provides impact definitions, distinguishes level of analysis required by NEPA class of action, and outlines scoping process.

Framework

Defines cumulative impact and key principles, provides impact definitions, distinguishes level of analysis required by NEPA class of action, and outlines scoping process.

5-step procedural process.

Helps practitioners complete thorough and defensible indirect and/or cumulative impact analysis.

Detailed instructions provided in the respective guidance documents.

Provides a simplified 6-step methodology for induced growth impact analyses compare to previous guidance.

Methods an extent of analysis based on project size, type, location, potential to affect environmental resources, and potential to affect.

Simplified 5-step methodology for cumulative impact analyses.

Methods and extent of analysis based on project size, type, location, potential to affect environmental resources, and potential to affect environmental resources, and potential to affect the health of any resource.

Defines the three types of impacts: direct, indirect, cumulative.

Compares impact types to each other and the project, and their respective timeframe, focus, study areas

Analyzes project’s likelihood to induce growth.

Separates the effects of induced growth from the project’s encroachment impacts.

Details key points of cumulative impact analysis process.

Focuses on whether there are substantial impacts on the resource, not whose actions are causing the impacts.

Summarizes requirements for agency coordination, public participation, documentation, the review and approval process. Explains how encroachment alteration indirect impacts differ from induced grown indirect impacts.

Lessons Learned

From its original cumulative effects guidance through its most recent guidance updates, TxDOT emphasized the following lessons that may be transferable to other state DOTs:

  • Know your state: A blanket approach to indirect and cumulative impacts analysis does not work in Texas. Though other state DOTs may have a more uniform statewide land use climate, it is critical to know your area and understand that indirect and cumulative impacts are complex and often call for a case-by-case approach. Texas uses decision trees (Induced Growth Indirect Impacts Decision Tree and Cumulative Impacts Decision Tree) to help determine which projects need indirect and cumulative impact analyses.
  • Simplify: TxDOT’s simplified approach to indirect and cumulative impact analyses made it more approachable for district environmental staff, who are project and technical experts but not necessarily versed in all aspects of NEPA.
  • Consider process improvements: By emphasizing technical reports and coordination early in the NEPA process, TxDOT was able to shorten their review cycles, save time and money, and produce stronger analysis in its documents.
  • Provide one-on-one coaching: In addition to regular conference calls (“NEPA Chats”) with districts to identify and provide guidance on various NEPA issues, TxDOT found great value in one-on-one coaching with district subject matter experts on individual projects rather than implementing agency-wide theoretical classroom training in how to apply the guidance.

For more information on TxDOT’s approach to Indirect and Cumulative Effects, contact Nicolle Kord, Environmental Specialist, Texas DOT at [email protected].