Geosynthetic reinforced soil (GRS) slopes and walls offer innovative, sustainable solutions by combining soil with geosynthetics to create stable, durable, and cost-effective structures. They address slope stability, erosion control, and retaining wall construction while reducing costs and construction time compared to traditional RCC walls. GRS structures can use local, eco-friendly materials, minimizing environmental impact, and are adaptable to various soil types, steep terrains, high rainfall, and seismic regions. One key application area for geosynthetic reinforced soil slopes and walls is for provision of retention work of roads, highway projects, and bridge approaches. The slope protection works for construction of highway infrastructure in hilly terrains typically involve the use of geosynthetic reinforced soil walls and slopes for retention work on the valley side. In the present paper, we primarily focus on the case study for design and construction of Geogrid–Reinforced Soil Walls and Slopes for Kaithlighat–Shakral stretch as a part of Shimla Bypass Project (Package-1) in the state of Himachal Pradesh. The study discusses the key design procedures and construction challenges, and the sustainable solutions adopted for the geosynthetic reinforced soil slopes and walls executed at Shimla Bypass Project (Package-1) primarily related to drainage and steep terrain at the project location.