sentences:  Proposed initially in the 2001 Cambridge-Huntingdon Multi-Modal Study, which recommended widening of the A14 road and construction of a guided busway along the old railway lines, construction began in March 2007 and it was opened on 7 August 2011 after a succession of delays and cost overruns.The original cost estimate of £116 million rose to £181 million by December 2010.An independent review of the project was announced on 21 September 2010, in which the Cambridge MP Julian Huppert at the time described the busway as a "white elephant".