Indirect and Cumulative Impacts
For every TxDOT project, environmental practitioners must assess the potential indirect and cumulative impacts to comply with the environmental project delivery process outlined in the National Environmental Policy Act (NEPA). The resources below include a collection of guidance from national transportation organizations and tools to assist with indirect and cumulative impact assessments for TxDOT projects.
Questions? Contact the Environmental Affairs Division's indirect and cumulative impacts specialist at 512-416-2698.
| Title | Date | Description |
| AASHTO Practitioner's Handbook 12: Assessing Indirect Effects and Cumulative Impacts Under the National Environmental Policy Act (NEPA) | Provides American Association of State Highway and Transportation Officials (AASHTO) guidance for assessing indirect effects and cumulative impacts for transportatoin projects. This also describes approaches for using the statewide and metropolitan transportation planning process | |
| Questions and Answers Regarding the Consideration of Indirect and Cumulative Impacts in the NEPA Process | Provides Federal Highway Administration's (FHWA) guidance by responding to frequently asked questions about indirect and cumulative impacts analyses | |
| SHRP2 Capacity Research: Interactions Between Transportation Capacity, Economic Systems and Land Use | Provides the results of the Capacity Project conducted by the second Strategic Highway Research Program (SHRP2) and designed to create a large database of case studies and a web-based tool, both allowing a faster assessment of the long-term economic impacts of highway capacity projects | |
| T-PICS: Transportation Project Impact Case Studies | Provides case studies, including project details, impacts, and factors affecting those impacts; allows searches for relevant case studies by using the type of project and setting; and allows searches for a range of likely impacts based on the studies by using the specific type of proposed project | |
| Texas State Data Center | Provides data on population estimates for places and counties that submitted age, sex and race and/or ethnicity details | |
| Eight Keys to Legally Sufficient ICI Analysis | Assists practitioners to produce a legally sufficient indirect and cumulative (ICI) impact analyses | |
| Statewide On-Road Greenhouse Gas Emissions Analysis and Climate Change Assessment Technical Report | 09/21 | Provides an analysis of: 1) statewide on-road and fuel cycle greenhouse gas emissions and strategies for reducing emissions, 2) climate change projections for Texas and 3) TxDOT’s current strategies for addressing the changing climate. It is a reference document that contains the analysis of climate change for TxDOT projects in the NEPA context. |
| Title | Date | Description |
| Guidance: Induced Growth Analysis | 12/23 | Provides instructions for conducting a six-step induced growth analysis for a transportation project |
| Induced Growth Indirect Impacts Decision Tree | 04/14 | Helps analysts determine if an induced growth analysis is necessary by showing the TxDOT process with all potential outcomes and places where decisions dictate which outcome is appropriate |
| Risk Assessment for Indirect Impacts | 04/14 | Completed to document and record the need or lack of need of an indirect impact analysis |
| Forecasting Indirect Land Use Effects of Transportation Projects | Provides the results of a study on methods for estimating changes to land use and is helpful for projects classified as environmental impact statements | |
| Desk Reference for Estimating the Indirect Effects of Proposed Transportation Projects (NCHRP Report 466) | Contains detailed instruction for completing an indirect impacts analysis and explains complex that are helpful for projects classified as environmental impact statements |
| Title | Date | Description |
| Cumulative Impacts Analysis Guidelines | 01/19 | Provides TxDOT guidance focused on the assessment of cumulative impacts of transportation projects on the natural and human environment |
| Risk Assessment for Cumulative Impacts Analysis Guidelines | 04/14 | Completed to document and record the need or lack of need for an analysis |
| Cumulative Impacts Decision Tree | 04/14 | Helps analysts determine if a cumulative impacts analysis is necessary by showing the TxDOT process with all potential outcomes and places where decisions dictate which outcome is appropriate |
| Consideration of Cumulative Impacts in EPA Review of NEPA Documents | Provides insight into the U.S. Environmental Protection Agency perspective for reviewing cumulative effects analyses | |
| Guidance on the Consideration of Past Actions in Cumulative Effects Analysis | Provides guidance from the Council on Environmental Quality on the extent to which agencies of the federal government are required to analyze the environmental effects when describing the cumulative environmental effect of a proposed transportation action |