LTNman
5 million would be the very maximum for SEN in my opinion and talk of 10 million is simply not achievable.
As far as road access is concerned it's not quite as you suggest and access from the A127 turn off (25 minutes from the M25) is just a couple of minutes along one road. Local access can vary according to the time of day obviously but SEN is on the northern edge of SEN so no one has to drive through the town to get to it.