The budget announcement on 20 December 2004 made provision for the development of the core part of the Northern Ireland Railways network in line with the funding estimates in the Railway Review Group (RRG) report. It also made provision for an element of capital renewal on the lesser-used lines in accordance with option 2 of the RRG report. The lesser-used lines are those between Whitehead and Larne, and between Ballymena and Londonderry (including a spur to Portrush). The option 2 proposal envisages some £17 million investment on the lesser-used lines over a five-year period and is designed to ensure the maintenance of services at current levels. While this approach effectively secures the delivery of rail services on the lesser-used lines during that five-year period, it makes no provision for any significant improvement to the rail services offered on those lines during that period. It is inevitable that there will be some degree of betterment arising from works to improve parts of the track or to enhance railway stations, but there are no plans to enter into any further funding commitments until it has been possible to review the impact of recent investment in the railways. This cannot be undertaken before 2007.