Routes
A connection to CBG would have its advantages for the medical/pharmaceutical industries along with technology companies and academics along side VFR(Plenty of northern students at cambridge) and other busniess travel needs where the train can be impractical taking up to 4 hours with changes.
A connection to BHX was viable until T3 messed it up changing the depart and arrival times which eventually made the service pointless for business day trips. A twice daily service to provide a full business day each way could be a very fruitful route as the trains are direct, although take up to 3.5 hours and the voyagers Class 220/221s are not the most pleasant for longish journeys.