How slugging works in Washington DC suburbs - sharing rides to work

Fredericksburg.com: "A form of Washington commuting. People assemble at meeting points and form a line. Drivers stop at the line and shout, “Pentagon!” “14th Street and F!” “Rosslyn!” The first people in line headed for these destinations hop in the car. Drivers gather enough people to use the I–95 express lanes for a free ride to work. The “slug” lines work in reverse in the afternoon, forming at the morning drop-off locations. There’s no fee or paperwork required to participate, for drivers or slugs. Just get in line. Veteran slugs carry laminated signs listing their morning and afternoon destinations. Visit slug-lines.com for a complete list of meeting places, times and social norms surrounding this practice."