The basic toll (for automobiles) on the seven state-owned bridges, including the Dumbarton Bridge, was raised to $1 by Regional Measure 1, approved by Bay Area voters in 1988. A $1 seismic retrofit surcharge was added in 1998 by the state legislature, originally for eight years, but since then extended to December 2037 (AB1171, October 2001). On March 2, 2004, voters approved Regional Measure 2, raising the toll by another dollar to a total of $3. An additional dollar was added to the toll starting January 1, 2007, to cover cost overruns concerning the replacement of the eastern span.