Work to introduce dynamic hard shoulder running on approximately of motorway between Luton and Milton Keynes (J10-13) was completed in December 2012, at a total cost of £327 million. This made the hard shoulder available to be opened as a traffic lane where additional capacity was necessary. Modifications were made to Junctions 11 and 12, to allow for four lanes running through each junction, and the A421 road from Junction 13 to the Bedford southern bypass was also upgraded to two lanes each way during this period. The scheme will likely be converted to all lane running at some point in the 2020 decade, alongside all other dynamic hard shoulder running schemes. This was because a Government review into smart motorways found dynamic hard shoulder running was too confusing for drivers, leading to plans to convert all dynamic hard shoulders into permanent running lanes.