The Maryland Transportation Authority held the first of nine public hearings on a proposal to raise tolls on the state’s bridge, tunnels and other roads. The hearing was held at Shady Grove Middle School. All the sessions will include a formal presentation and testimony. The proposals include increasing tolls for passenger cars on the Chesapeake Bay Bridge from $2.50 to $5 starting October 1, and to $8 beginning in July 2013. One-way tolls for the Harbor Tunnel, Fort McHenry Tunnel and the Key Bridge would go from $2 to $3. The agency gave preliminary approval to the increases last week.