Work Plan
NTPEP tests products according to a Project Work Plan, which describes the laboratory and/or field test protocols used to conduct the evaluation. The Project Work Plan is a consensus-based document, and includes peer review and input from industry experts. Each Project Work Plan is adopted after receiving at least two-thirds affirmative support from 52 AASHTO member states. The Project Work Plan is the basis for host states to conduct their testing and evaluation. When implemented by state DOTs, their own state standard specifications may supersede the NTPEP Project Work Plan. Industry is advised to be aware of state-level requirements, which may supersede basic NTPEP testing.

GTX Work Plan
REGEO Work Plan

Audit Documents 
  Please visit the NTPEP Audit Documents web page for blank audit reports


Product Evaluation Documents
             Private/Converter Source Verification Forms
User Guide - GTX Source Verification Forms​​
                         WEBINAR - Sept. 1, 2016 - User Guide Walkthrough

Participating Geotextile Manufacturers

A list of participating Geotextile manufacturers with a quality management system found to conform to the NTPEP GTX work plan.​


Additional Documents

REGEO Installation Damage and Use Survey Summary by Tony Allen, GTX/REGEO Technical Committee Chairman