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• #### Abbreviations used without definitions in TRB publications 135-135

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96 Estimating Soft Costs for Major Public Transportation Fixed Guideway Projects LIGHT + HEAVY RAIL: ALL SOFT COSTS LIGHT + HEAVY RAIL: ADMIN COSTS ONLY 60% 35% Management (% of Construction) 50% 30% 25% Soft Costs (% of Construction) 40% 20% 30% 15% 20% 2 10% R = 0.01 2 R = 0.09 10% 5% 0% 0% (2) - 2 4 6 8 (2) - 2 4 6 8 Years of Delay Years of Delay 2 2 Sample Size: 15 R = 0.01 t-Stat = -0.43 Sample Size: 15 R = 0.09 t-Stat = -1.14 Figure 72. Soft costs as a percentage of construction versus years of delay in opening. Figure 73 and Figure 74 examine this potential explanation by comparing the rate of growth of soft and hard costs as the vertical profile becomes more complex. Soft and construction costs are on a per-linear-foot basis, and in every pane construction costs are shown as green diamonds, with a green dashed trend line. Figure 73 shows that for light and heavy rail and both modes combined, as more of the align- ment is in cut and cover and tunnels, construction costs rise faster than soft costs. Figure 74 shows a similar trend when alignment is simply not at grade, although the pattern is less strong. These trends affirm that when the alignment moves from at grade to more complex tunnel, bridge, or aerial structures, construction costs expand rapidly, sometimes faster than soft costs. C.16. Isolating Agency-Specific Effects One potential source of variance within the dataset used here is that financial and construc- tion management practices differ from agency to agency. Where one agency maintains construc- tion inspectors and managers on staff through the operating budget, another agency might LIGHT RAIL HEAVY RAIL LIGHT + HEAVY RAIL \$40 \$60 \$60 Construction Costs Construction \$35 Costs \$50 \$50 Construction Costs per LF (000) Costs per LF (000) 2 Costs per LF (000) \$30 R = 0.38 Costs \$40 \$40 \$25 2 R = 0.19 \$20 2 \$30 \$30 R = 0.18 \$15 \$20 \$20 \$10 2 2 2 R = 0.03 R = 0.27 R = 0.41 \$10 \$10 \$5 Soft Costs Soft Costs Soft Costs \$- \$- \$- 0% 25% 50% 75% 100% 0% 25% 50% 75% 100% 0% 25% 50% 75% 100% % Guideway Below Grade % Guideway Below Grade % Guideway Below Grade 2 2 2 Soft Costs trend: R = 0.41 t-Stat = 3.87 R = 0.03 t-Stat = 0.76 R = 0.27 t-Stat: = 3.94 Figure 73. Soft costs and construction costs per linear foot with percent of guideway below grade.

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