West Pipkin Road Widening
PGA worked closely with Polk County on West Pipkin Rd. to increase capacity while accommodating all users for two separate segments: 1) from Medulla Rd. to Dossey Rd. and 2) from Dorman Rd. to SR 37. The first (west) segment widened the existing two-lane rural roadway to a four-lane urban facility with buffered bike lanes and sidewalks on both sides. The second (east) segment widened W. Pipkin Rd. from a two-lane to a three-lane facility, improving access management and providing a sidewalk on the south side and accommodating the ultimate five-lane typical section. The design for this project included a large pond (SMF 14-2) that was optimized by lowering the control elevation without a liner. The additional capacity generated in this pond serves as surge capacity for Poley Creek. A groundwater model was developed to demonstrate no adverse impacts to adjacent wetlands resulting from the lowered control elevation. The design for this project also included diversion structures in different locations to allow high flow storm events to “pop off” to adjacent basins and balance the hydraulic grade lines for better flood protection. PGA handled the roadway, drainage, environmental, and structures design for the project.