The southern portion of SR 125 from Otay Mesa Road to SR 54 near Chula Vista is a toll road called the South Bay Expressway. This portion was completed in 2007 after many years of planning and litigation related to concerns over the destruction of endangered species habitat. The toll road was operated by a public-private partnership known as South Bay Expressway LLC. However, the partnership declared bankruptcy in 2010 and sold the road to the San Diego Association of Governments (SANDAG) in 2011. Since then, following a decrease in the toll amount, traffic using the highway has increased.