The usual traffic diversity means you'll be constantly regulating the flows to avoid any delays as far as possible.
The area is comprised of four screens covering the main line from Stansted to north of Ely, including Cambridge and Ely stations, A fifth screen provides branch lines towards Royston, Dullingham and Chippenham Junction, and a sixth gives a simplified view of the line through March to Peterborough.
*Cambridge v2.105 (July 2007 Beta) signalling diagram including level crossing listing. The 2009 release is very slightly different but this will still provide a good guide.
The file is an Adobe Acrobat PDF file. If you don't have Adobe Acrobat Reader installed on your computer you can get a free download of the latest versions from the Adobe website. The last time I looked it had reached v9 and the download was 33.5Mb.