The average person is the driver on 435 trips per year, and the average household is 2.36 people. Do people in Cambridge really drive 4 times as much as average, when only 41% of commuting is by car as opposed to 71% nationally? (Both commuting figures include being a passenger too, nationally commuting is responsible for 19% of all trips).
Update: Well, here is the study on Cambridge East, and I can't make the numbers add up to 125,000 car trips per day even by doing insane things like assuming the peak traffic flow levels given are sustained 24 hours a day. Oh, and also note that the 11,500 houses are going in phases, with about a quarter not being built until "after 2021", so it's not like there'll be an overnight rush. Oh, and that document also says "If developed to its full scale, it will have a residential population of just under 30,000", answering any pedants who might claim that greatly above average population density would be another condition that'd satisfy my assumptions above.
¹ never mind that these houses are probably (I don't know for sure) part of central government targets … oh, so they are, or at least the local plan has been adopted into the regional plan by central government as a large part of the 47,500 houses that have been assigned to the Cambridge sub-region.