Aberdeen staff outline preferred US‑12 overcrossing design, seek council confirmation before right‑of‑way purchases

Aberdeen city staff and consultants updated the City Council Jan. 22 on the US‑12 Highway‑Rail Separation (HRS) project, describing a preferred overcrossing that would build a two‑lane roundabout on US‑12, an overpass across the Puget Sound and Pacific Railroad (PSAP) trestle and an eastbound auxiliary ramp to relieve backups when trains block US‑12.

The project aims to reduce congestion on US‑12 when trains block the trestle, improve emergency access to the commercial area along the Chehalis River, and provide better pedestrian, bicycle and transit access to downtown businesses, project manager Deborah Seaman said. "We have to be 23 feet from the top of the railroad track to the bottom of the bridge girder," Seaman said, describing the clearance requirement that governs the bridge profile and ramp slopes.

The preferred alternative, which Seaman said evolved from a multi‑year alternatives analysis, would build a roundabout at Newell Street on US‑12, carry traffic up and over the railroad, and drop it down into the commercial area. An eastbound auxiliary ramp would allow some eastbound traffic to bypass the roundabout and limit queuing in front of major properties. Consultants said they…