81 Transportation Research Record: Journal of the Transportation Research Board, No. 2511, Transportation Research Board, Washington, D.C., 2015, pp. 81–89. DOI: 10.3141/2511-10 This paper presents the findings from an ongoing research study that evaluated two recently developed geosynthetic products: a triaxial geogrid and a high-strength woven geotextile for reinforcing or stabilizing roads constructed over native soft soil in the state of Louisiana. Six full-scale test lane sections were constructed: two were reinforced by one and two layers of triaxial geogrids, respectively, while high-strength geotextile was used to reinforce two of the other sections with aggregate layers of different thicknesses. The remaining two sections were left as controls: one was constructed over a sand embankment 30 cm thick representing the common practice in southern Louisiana. The unpaved test sections were subjected to a full-scale moving wheel load applied by the acceler- ated loading facility. A variety of instrumentation was used to measure the load-associated and the environment-associated pavement responses and performance. Results of the full-scale testing on the unpaved test sections demonstrated the benefits of geosynthetic reinforcement–stabilization in reducing the permanent deformation in the pavement structure. The test sections’ resilient behavior did not seem to be influenced by the presence of geosynthetics. In addition, instead of the soft soil subgrade, the aggregate layer was the primary contributor to the total permanent deformation– surface rutting of the unpaved sections under the testing conditions in this study. Geosynthetics were mobilized and generally exhibited a strain around 0.2%. In the state of Louisiana, roads often have to be built over weak sub- grades because of the soft nature of Louisiana soil and the presence of a high groundwater table, which creates many roadway design and construction challenges. A common practice of treating soft sub- grades in Louisiana is mixing the upper subgrade soil with lime or cement (1, 2). Facing the challenge of growing demands for road usage and constrained funding, transportation professionals are constantly seeking alternative, cost-effective roadway design, construction, and materials. As an alternative construction material, geosynthetics offer a potentially economical solution for reinforcing–stabilizing roads built over soft subgrade soils. Numerous studies have revealed that using geosynthetic reinforce- ments in roadway structures either extends a road’s service life or reduces the thickness of the structural layer, especially the aggregate layer, with an equivalent performance (3–8). Two recently developed geosynthetic products—a triaxial geogrid and a high-strength woven geotextile—have been tested by a limited number of studies and shown to provide benefits in roadway structures (9–11). In particular, the triaxial geogrid with triangular aperture has demonstrated more uniform strength and stiffness in all directions and enhanced aggregate interlock compared with traditional biaxial geogrids (12, 13). With the release of the new pavement design program Pavement ME by AASHTO (14, 15), mechanistic–empirical (ME) pavement design and analysis is becoming routine practice for pavement engi- neers in the United States. Recent studies of geosynthetic applica- tions in pavements have been focused on quantifying the effects and benefits of geosynthetics and incorporating them into the ME analysis and design (16–19). The authors recognize that, in the ME design process, achieving realistic and reliable critical pave- ment mechanistic responses remains a challenge, although analyti- cal solutions and numerical modeling are available for predicting pavement responses with assumptions to various extents. The inclu- sion of geosynthetics further adds to the complexity of the pavement system and prediction of its responses (20–23). Because embedding instrumentation in pavements is perhaps the most reliable way to measure in situ pavement responses and performance, numerous studies have used a variety of embedded instruments to monitor the behavior of specially constructed or in-service pavements, a few of which have involved the full-scale testing of geosynthetics in pavements (17, 24–29). Aimed to evaluate the two recently emerged geosynthetic prod- ucts, full-scale accelerated traffic testing is being done to test six heavily instrumented test sections built over native soft Louisiana soil. The overall objective of this ongoing research project is to assess the effectiveness and to quantify the benefits of using the two new geosynthetic products for reinforcing–stabilizing pavements. The project is being performed in two phases: (a) the Phase 1 study is conducted before the construction of the asphalt layer and focused on accelerated traffic testing on the unpaved test sections to simulate prerutting of the roads and possible prestressing and mobilization of the geosynthetics because of construction traffic; and (b) the Phase 2 study is focused on accelerated traffic testing on the asphalt layer to evaluate the performance of paved test sections with and without geosynthetic reinforcement–stabilization. While the Phase 2 study is underway, the scope of this paper is limited to presenting results and findings from the Phase 1 study on unpaved test sections. Performance of Reinforced–Stabilized Unpaved Test Sections Built over Native Soft Soil Under Full-Scale Moving Wheel Loads Xiaochao Tang, Murad Abu-Farsakh, Shadi Hanandeh, and Qiming Chen X. Tang, Department of Civil Engineering, Widener University, 1 University Place, Chester, PA 19013. M. Abu-Farsakh and Q. Chen, Louisiana Transporta- tion Research Center, 4101 Gourrier Avenue, and S. Hanandeh, Department of Civil and Environmental Engineering, Louisiana State University, Baton Rouge, LA 70808. Corresponding author: M. Abu-Farsakh, cefars@lsu.edu.