The Virginia Railway Express commuter service is ironing out details to expand into Spotsylvania County, with plans to open its first station there late next year.

Train officials are working out the details with the county on building a new station and platform to become the new end for the Fredericksburg line. The service now runs on two lines, shuttling Northern Virginia workers to their D.C.-area jobs. But the march outward signals the continuing reach of the D.C. region’s sprawl and workers’ desire for an alternative to sitting in traffic.