The A1M is already at a standstill by 0645 most mornings and Stevenage train station has already got noticeably busier in the last five years (I'm a rail commuter). Where's the plan for dealing with the extra traffic? You can't just add another platform or extend driving into the hard shoulder and think it's all going to be enough - as it just pushes the problem further up north.
Not to mention the pressure on services such as the Lister hospital, schools, GPs and the Green Belt. DEVELOPMENT HAS TO STOP SOMEWHERE!!!!