Motorway displays to tackle highway robbery at the pumps The scheme is the first significant idea from David Cameron's new policy unit, which is headed by Jo Johnson, the brother of Boris Johnson, the Mayor of London. Mr Cameron has asked the policy unit to make the cost of living a priority, according to sources. The problem on the motorway is that the fuel prices are only advertised on the forecourt. That is the legal requirement. But by the time you've pulled off the motorway and stopped, it is often more trouble than it's worth to go on to the next service station, particularly as you've got no idea whether it will be any cheaper. The reforms will not force fuel providers to cut their prices, however. Ministers believe that increased transparency will encourage stations to be more fair. The review is part of a wider drive to tackle the rapidly rising cost of living, which ministers think will be a major issue at the next election. "The policy unit will look more generally at how transparency can drive down prices," the source added. We have acted already on energy prices, to ensure people get put on the lowest tariff, and we will look at other areas to see what more we can do. Petrol prices rose by 38 per cent between June 2007 and June 2012, while diesel prices went up by 43 per cent. In the 10 years between 2003 and 2012, petrol prices increased from 76p per litre to 136p, and from 78p to 142p for diesel.