Glenn and 25Hz - have you factored in both routes when calculating grade? In other words, raising one and lowering the other. You may have, but if you haven't, that cuts the distance in half. What is the remaining life on the Huntingdon Pike overpass? Finally, are you using modern grade guidelines, or old ones? (wait - can the SL-Vs even go up hills?)
Nerodon is right about study sandbagging. The last real "Rail" study showed 2200 riders in 1995 and reasonable costs for Newtown. I think it was 65 million.
In 2012, 3000 new riders and a price tag between 150 and 300 million seems to be agreeable to most. Several weeks ago, an Inquirer article about the City Branch called $115 million "pocket change as transit projects go."
It's simply not true that the Newtown-Southampton corridor is well served by West Trenton and Warminster, at least not in the last 10 years. Both of these routes are maxed out. Expansion of parking facilities, on either line, is likely more costly per rider than bringing Newtown back online. At this point, we've exhausted the low hanging fruit for Lower Bucks rail. Not to mention that the roughly 8 mile stretch on Street Road between Warminster and Trevose is virtually unnavigable at rush hour. So while we often hear about how close these other lines are, the reality is that they are NOT viable options for many people.
Once again, while I agree times are not ripe for big projects, reigning in some of the nonsense projects is long overdue. Enough with the bus loops, electronic signs, traffic signal preemptions, etc. None of these add ridership, and it's becoming quite clear that simply asking Harrisburg for more funding isn't working. On the other hand, more ridership=more votes=more funding.