I realize I just commented on this. The real study is here:
Summarized by Jeffrey Pieters the Post Bulletin: Study: Zip Rail would boost state economy by $1 billion per year – Post Bulletin:

”
Nearly $1 billion per year in increased economic activity would result from a proposed Rochester-to-Twin Cities high-speed Zip Rail line, concludes an analysis produced for Rochester Area Economic Development Inc.
“We think this study makes it clear — the benefits are significant and net-positive,” said RAEDI Executive Director Gary Smith.
The study, prepared for RAEDI by R.L. Banks & Associates, an Arlington, Va., consulting firm, was commissioned to answer this “central question,” Smith said — “What would happen if we shrunk the time and distance between the Rochester-area economy and the Twin Cities economy.”
The purpose of the study, Smith cautioned, is not to establish the feasibility of the route and its estimated $1 billion construction cost. The study was merely a statistical analysis of the likely economic benefits, calculated using certain established formulas and assumptions.
“We thought it was important to weigh in, if you will, on the potential economic effect of this,” Smith said. “There’s enough economic benefit here this warrants further study and analysis.”
The study assumed a nonstop route between downtown Rochester and Minneapolis-St. Paul International Airport. Such a route would attract an estimated 1 million riders per year, the study assumed.
Trains traveling at speeds between 150 and 220 mph would shave 30 minutes off the travel time by car and make the travel time itself potentially productive for the travel freed from the task of driving.
Benefits accrue from that increased productivity, as well as from tying together the unique biomedical and research economies of the two metro areas, said Frank Loetterle, transportation planner with R.L. Banks.
“There’s a synergy that occurs here … that doesn’t occur other places,” he said.
Some of the specific findings of the analysis include:
• Statewide, economic activity would increase by $987 million per year, and by $84 million in Olmsted County alone.
• Increased employment, over 25 years, would total nearly 7,900 jobs, including 3,250 involved in the planning, design and construction. More than $7.6 billion in individual income is attributed to the job increase — again, over the 25-year time span analyzed.
• The value of time-savings from the high-speed link would approach $30 million in the first year of operation, and vehicle gas consumption would be reduced by 2.5 million gallons. An estimated 40 road crashes would be prevented.”

OK, to be more serious. Think about these results:
A line that carries 3000 people each way per day maximum (10 one-way trips of 300 passengers each) will generate 7888 jobs.
Only 610 of those jobs are in Olmsted County. So most people who benefit are elsewhere in the state because of the accessibility benefits given to the airport and the Mayo clinic … ? We have evidence of all this job growth from what? There is no US experience on which to validate job increases associated with HSR infrastructure.
Driving is assumed to be non-productive time. They have not heard of autonomous vehicles, which I hope will be quite available in well less than 30 years. Thus time savings is all of auto travel time, not just the difference in travel times. Passengers of autos seem to be counted as non-productive as well. The sick Mayo patients on-route will be productive. Nice to hear. Maybe they will want to rest up?
I will not comment much on the safety benefits, which are relatively small. It is a needlessly dangerous section of highway which could (and undoubtedly will) be fixed for less than the cost of this ZipLine. Nevertheless, cars will get safer over time for a variety of reasons, even if you don’t assume automation.
Petroleum use is assumed fixed, 2.5 million gallons. I.e. in 30 years, autos will still get 20.3 mpg and buses 3.7 mpg.
Tax revenue is counted as a benefit.
The annual ridership is assumed to be about 1 million, which exceeds the best-case forecast of the Minnesota Comprehensive Statewide Freight and Passenger Rail Plan of 750,000. In 2008, total trips between Twin Cities and Rochester where just under 2 million, so they expect to capture half of all of the trips.
Unless those trips are destined for the rail stations on either end, they will need to transfer. Most people do not live at the airport or in walking distance of downtown Rochester. Aside from Mayo patients flying in, there is not much market there. I would be surprised if that were anywhere near 1 million patients per year.
At present there is no congestion between Rochester and MSP on highways. A distance of 77 miles is covered in 75 minutes.
I am sure I am missing obvious critiques, since I am doing this on the fly. Feel free to chime in.