The Modernisation Plan of 1955 was intended to re-cast the railways with money being spent on infrastructure, signalling, electrification, the acquisition of diesel locomotives, and other wide ranging enhancements. Dogged by complex and fluid governance issues, interference from government, and the retention of technologies, operational, and commercial models, the railways were in an acute spiral of decline. The Modernization Plan envisaged a major period of investment to arrest the spiral of financial decline. Major infrastructure schemes were advanced some of which soon turned into expensive "white elephants." Freight traffic continued to hemorrhage due to the retention of methods and systems increasingly at odds with what shippers wanted. Within the rail sector there was little evidence of any real capability in forensic market planning, product and service development. To many the Modernization Plan was effectively more of the same but with up-to-date equipment. Arguably major opportunities were lost to make the railways more cost effective, competitive, and attractive, but with endless internal changes in governance and indecision by governments the resultant mess hamstrung the railways in Britain and condemned it to further decades of indifferent performance.

The final years of the BRB saw major long overdue changes in sorting out long standing organizational, technical, managerial, and commercial issues before being engulfed by privatization. Arguably this sort of approach should have governed the development and implementation of the Modernization Plan. The internal wrangles within the industry and with government dogged its performance and led to its marginalization. Serious errors were made. Others were blamed for the fall out.