Speed cameras were erected on the bridge in 2004, but were not activated until September 2005, because of issues with a similar camera on the Western Ring Road. However these speed cameras were switched off in 2005, and currently remain disabled, as the sway of the bridge prevents secondary verification of the alleged speed against a fixed point. In 2006 the State Government spent $1.3 million on erecting railway style boom barriers at each entrance to the bridge to block traffic in the event of a terrorist attack. In March 2007, the State Government announced that two flagpoles would be erected atop the main bridge pylons, to fly the Australian and Victorian flags, each being in size and above sea level. Costing $350,000 to install and $15,000 a year to maintain, the flags were unfurled on 24 September 2008.