During 1999, the first proposals for the route, prepared by the national Rail Planning Committee, were rejected by the Danish Parliament, leading to further studying and refinement.

By late 2017, reports emerged of severe difficulties having been encountered with the new line's signalling system; according to project officials, initial operations are to be limited to only one train per hour for the first year while remedial work is performed.

During the late 1990s, the conventional railway between the Danish cities of Copenhagen to Ringsted became highly congested, forming a bottleneck along that section of the Copenhagen–Fredericia/Taulov Line.

Recognising the necessity of addressing this situation, Danish officials began to consider various methods intended to resolve this.

[2] In 1993, the first proposals for improving railway transportation between Copenhagen and Ringsted were formalised; one of the early options to be explored was the construction of new main line-standard tracks between Hvidovre and Taastrup.

During 1994-1997, the Rail Planning Committee decided to expand the railway lines in order to meet passenger capacity between Copenhagen and Ringsted and suggested various specific methods, such as expansion with two new tracks.

[6] During May 2010, the greenfield solution for the line received approval from the Danish Parliament in the form of the Construction Act.

[7] In total, a 60 km (37 mi) section of new dual-track electrified railway, capable of handling speeds of up to 250 km/h (155 mph) for passenger trains, is to be built; reportedly, this undertaking would be the largest rail programme to ever be performed by national railway infrastructure agency Banedanmark.

[8] The line will also be linked to an existing 180 km (110 mi) railway that passes between Copenhagen and the Danish land border with Germany.

[2] During January 2011, it was announced that a consortium of Vössing, EKJ Consulting and Sweco, led by engineering company Atkins, had signed a contract with Banedanmark to design the first stretch of the railway line.

[2] During June 2013, a consortium of Barslund and CG Jensen received a contract for the construction of a bridge on Brondby Østervej, as well as a railway tunnel near Holbækmotorvejen, and a pass through Vestvolden.

[12][11] On 12 September 2012, a ceremony officiated by the then-Minister for Transport Henrik Dam Kristensen was held to mark the commencement of construction activity on the new line; at the occasion, much fanfare was made of the improvements to international travel that it promised to enable once completed.

Because of difficulties in provision of ETCS (signalling and control component of the ERTMS) onboard equipment to the trains some replanning has happened.

[16] Being initially opened without the ETCS signalling system (using ATC instead), the maximum operating speed of the line was reduced to 180 km/h (112 mph) and its capacity limited to 5 trains per hour.