4.4. SR 03-17-2003 - Laserfiche WebLink

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Differences in Assumptions These calculations involve many different assumptions and parameters. However there are a small number of key assumptions that can explain most of the differences between the three studies. The MnDOT and Anton, Lubov studies differ only in a few assumptions but the differences between the PB study of the Elk River line and the two Northstar studies are many. It is easiest to discuss the differences between by considering the differences between the PB and MnDOT studies first and then discussing the differences between the MnDOT and ALA studies. Parsons-Brinckerhoff vs. MnDOT There are a number of differences in the assumptions underlying these two calculations: Not the same corridor The most obvious difference is that the two calculations were made for different train routes. PB analyzed a corridor from Minneapolis to Elk River while MnDOT study is of the full Northstar Corridor from Minneapolis to Rice. The Northstar corridor is 82.2 miles long. The PB calculations assume that the distance to Elk River is 41.2 miles even though their maps indicate the distance as about 30 miles. ( The distance to the Elk River station included in the Northstar proposal is 28.2 miles, but the station is located south of the end of the line analyzed by PB.) This distance has the effect of lowering the cost of the Elk River line relative to the full Northstar line. It also leads to the second difference. Different ridership forecasts The PB study used a ridership forecast that predicted that there would be only 3,453 trips per day on the Elk River line. In contrast, the ridership forecast prepared for the Northstar line following the standard methodology endorsed by FTA shows 9,594 daily trips. That is, roughly 3 times as many people are expected to ride the Northstar Commuter Rail to and from Saint Cloud as PB expected to ride the Elk River line. Roughly speaking, tripling ridership can be expected to triple the benefits of a project other things being held equal. Different capital costs MnDOT used the actual estimate of $278 million generated from the engineering studies of the Northstar corridor. PB used per mile cost estimates of the much shorter Elk River line to estimate a total capital cost of $144. Weekend Operation Parsons-Brinckerhoff assumed that the Elk River line would not operate on weekends. The current plan is for the Northstar Commuter Rail to provide limited weekend service. 9