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Cost Benefit Analysis

Cost Estimates

Cost estimates were performed on each of the alternatives using the 2014 Caltrans Database. The major items in our cost estimate include: Roadway, Structure, and Right-of-Way with supporting costs for Design, Construction & Administration, and Contingencies. Below is a summary of each alternatives cost.

Continuous Flow Interchange

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**Based on Caltrans Database (2014)**


Diverging Diamond Interchange

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**Based on Caltrans Database (2014)**


Single Point Urban Interchange

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**Based on Caltrans Database (2014)**


Cost Estimate Summary

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**All values are in millions**

Benefit Estimate

Benefit estimates were also performed on each of the alternatives. The benefit factors considered were Total Reduced Vehicle Stops, Total Reduced Vehicle Delay, Total Reduced Fuel Use, and Total Reduced CO2 Emissions. These factors were assigned a monetary value for each year of the facility's 20 year design life. A present worth calculation was then performed to determine the total benefit of each alternative in 2014 dollars. Below is a summary of each alternative's total benefit.

Continuous Flow Interchange

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Diverging Diamond Interchange

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Single Point Urban Interchange

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Benefit Estimate Summary

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**All values are in millions (over 20 year design life)**

Benefit Cost Ratio

A benefit-cost analysis is a systematic process for calculating and comparing the benefits and costs of a project. It has two purposes: one, to determine if a project is a sound investment and two, to provide a basis for comparing project alternatives. The benefit-cost ratio is a representation of how much the benefits of a project outweigh its cost. This table lists the cost, benefit, and benefit-cost ratio for each alternative. The CFI and DDI have a B/C ratio over 1.0 which means the benefit of these alternatives outweighs its cost. This is not the case for the SPUI with which has s B/C ratio of less than 1.0, meaning this alternative's benefit doesn't outweigh the cost.

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**Values are in millions, year 2014**

Weighted Decision Matrix

We decided to select our recommended alternative by using a weighted decision matrix. We started by listing design factors, such as "Local Circulation," "Freeway Operations," "Benefit," and "Cost" and then putting them in order of importance based on Caltrans, City, and Community needs. We then scored each alternative from 1 to 10, as to how well they met each design factor. For an example of our scoring methodology, "Local Circulation" was based on the average intersection level of service in 2040. From our data we gave the CFI an 8, the DDI a 6, and the SPUI a 9. After giving a score to each alternative, we assigned numerical weights to each factor, giving the most important the highest weight. We then multiplied these weights by the scores, to get "weighted scorings." After totaling these weighted scores, the CFI had a total of 259, the DDI, 222, and the SPUI, 231.

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From these totals we selected the CFI as our Recommended Alternative.