OPTION W8: |
Description | Double deck entire two track section. |
Pros | Meets the expected capacity requirements, Speed increase buy making tunnel bore same one way with no aerodynamic constraint on upper level when opened out. |
Cons | Visually awkward to Digswell valley, Difficult construction, which will cause major disruption during construction, "Opening out" (as option W2) required for high level tracks, Major environmental disturbance, High cost. |
Summary | Costly and very disruptive. |