Dr Mawhinney said: 'The Government has announced its intention to introduce electronic tolling on motorways when the necessary legislation is in place and the technology is ready.
'This decision followed a programme of research and a public consultation based on the Green Paper 'Paying for Better Motorways'. That paper set out the arguments in favour of tolling.
'The government made clear its belief that tolling will provide another source of funding to speed up much needed motorway improvements. It further confirmed that toll revenue would be used only to improve the tolled network'.