Engineering group Costain said it had secured three additional highways contracts worth a minimum of 15 million pounds.The first, a four-year technology contract, is for the maintenance of Road Network Communications and Tunnel Systems across Wales and worth around £15m.It involves routine maintenance and fault repair of technology systems such as CCTV cameras, variable messaging signs, emergency telephones and traffic signals and includes the strategic routes of the M4, A55, and Conwy tunnels. Costain will commence the new service in early 2013, following a transition and handover period.The company has also been appointed onto both North and South lots of the Highways Agency Asset Support Framework.The framework allows the Agency to call on suppliers, including Costain, for larger maintenance schemes and improvement works, up to the value of £15m each.There is no commitment by the Agency to spend under the framework, but Costain said over £750m of work packages were expected to be awarded through it over the next three years.