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Shared-Track: A Handbook of Examples and Applications 67 Table 17. Worksheet 9--Typical key evaluation measures. Option 1 Option 2 Option 3 Option 4 Operating Regime Temporal Spatial Concurrent Concurrent Separation Separation Single Track Double Track Capital Cost ($ Millions) Annual Operating Cost ($ thousands) Daily Ridership Capital Cost per Weekday Boarding Operating Cost per Passenger Trip Farebox Recovery 65% 71% 71% 68% Mobility : Cost Index 69 59 77 59 research. The difference is small between the alternatives. Shared-track operations of this nature achieve economy though savings in capital costs. Farebox recovery ratio. The percentage of operating costs covered by passenger fare revenue will come to between 65% and 71% for the four service options considered in this research. This ratio is fare dependent. This range is close to the reported farebox recovery ratios for the San Diego Trolley at 87% in 1985 and 67% in 1997. It is substantially higher than most smaller com- muter rail systems. Business Case Findings Findings of the business case template are shown here. The reader may wish to review the Task 10 Report "Hypothetical Case Study" for a comprehensive analysis of all factors cited. 1. The compliant vehicle alternative may not satisfy local transit needs. 2. The temporally separated option may generate less ridership, while saving a percentage in capital cost and annual operating costs. 3. The spatially separated option may increase capital costs by a significant percentage, but generate the same level of ridership as the concurrent track sharing option. 4. The shared double track option increases capital costs by a significant percentage and operat- ing cost by a marginal percentage, but it also generates the same level of ridership. The benefit of double track includes reduced risk and improved flexibility. The decision is site specific, but the analysis demonstrates that double tracking at the outset seems to defeat the purpose of a low cost shared-track service. While affirmative indications of the business case are necessary, these are not solely sufficient justification to forge ahead. Most institutional concerns cited in the business case are addressed via legal agreements, financial arrangements, memoranda of understanding or other official and formal commitments. Risk analysis remains an outstanding and a major hurdle in the process. Risk analysis is a component of the safety case. And the safety case is essential to support the business case. Risk Analyses Template Introduction A simplified risk analysis is provided to estimate the relative risk of casualties to train occu- pants in train accidents for each of the four alternative options defined. The purpose of the analy- sis was to determine whether concurrent shared-track and shared corridor operations, as defined