It has shortlisted three agency groups to pitch. The advertising agencies are: The Red Brick Road, Archibald Ingall Stretton and Delaney Lund Knox Warren.
The pitches are expected to take place next week with an outcome expected soon afterwards.
The winning agencies will be briefed to create an integrated campaign to promote the company's aim of reducing car journeys by one billion by 2013 in a bid to reduce carbon emissions.
The group claims that research indicates that one-fifth of motorists find driving increasingly stressful and would prefer to reduce their car use. Meanwhile, a further fifth of motorists have already reduced their car use and would make further reductions if travelling by public transport was made easier.