Instead of working over 54 weekend closures of the West Coast Main Line at Watford, the contractors will aim to complete the work in just five longer possessions of a 12-mile stretch of track, in a bid to reduce disruption.
The scheme begins in May 2014 and continues over 16 days between 9-25 August 2014. Further work is also scheduled to take place over Christmas 2014 and in early 2015.
Siemens is responsible for the signalling renewal; Amey Colas is doing the track and overhead line work upgrade.
Network Rail route managing director Dyan Crowther said: “This scheme represents significant investment in the southern end of the West Coast Main Line to improve punctuality and make the railway more reliable.
“This line has seen tremendous growth in traffic and passengers over the last five years with the section at Watford being one of the most intensively used, high-speed sections of track in the UK. This work is absolutely essential to maintain the punctuality that passengers and our freight customers rightly expect. “
“There is never a good time to carry out major work on such a busy route. However, after careful discussion with the train operators and industry partners, it became apparent that carrying out this vital investment over five longer closures between May 2014 and Easter 2015 when fewer people travel would, overall, cause less disruption.”