Anyone who has taken a labor economics class can tell you that unions have two priorities. Those are protecting their membership and getting more of them. So its not too surprising to hear Teamsters in Pennsylvania say that their "members come first" and that they're "interested in keeping our jobs for our members."
The issue is whether Pennsylvania can lease the turnpike and raise a projected $18 billion for new transportation investments throughout the state. Several Pennsylvania communities suffer from congestion, which is only going to get worse without significant investment. A truly viable alternative to leasing the turnpike has yet to be discovered (with the exception of raising a host of taxes and fees), yet it seems that the Teamsters have put their members needs over the rest of the Commonwealth. Some 2,000 jobs -- most of which would still exist under a privatized operation (the toll takers would likely be phased out as technology can replace them over time).
All of Reason's work on transportation can be found here.