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Chapter 3 - Spreadsheet Tool
Pages 16-31

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From page 16...
... When analysts estimated models excluding the variables, the variable coefficients often had counterintuitive effects. Therefore, estimating the RTOR volume requires a preliminary signal timing plan.
From page 17...
... These capabilities were not built into the spreadsheet tool because the HCM Computational Engine already handles these other situations; instead, the RTOR equations were integrated into the HCM Computational Engine. Therefore, while the spreadsheet is able to illustrate the use of the RTOR equations for a subset of intersection situations, the modified HCM Computational Engine including the RTOR equations permits more general use.
From page 18...
... . • Thru Lane Saturation Flow Rate.
From page 19...
... Figure 9. Site worksheet showing locations for site and signal configuration entry.
From page 20...
... A Figure 10. Analysis worksheet showing locations for volume entry and LOS results.
From page 21...
... The right-turn volume will be adjusted by subtracting estimated RTOR volumes based on a multiple-variable negative binomial model that incorporates conflict ing volumes. – Volume Model 3.
From page 22...
... If the data are not known, suggested values for platoon ratio are provided in Table 5, which includes given platoon ratio values for different qualitative arrival types. • Incremental Delay Factor, k.
From page 23...
... Sometimes, the signal timing for a location is not known in advance. For this situation, a tool is included with the spreadsheet that will suggest a cycle length and splits appropriate for the given Table 7.   Recommended upstream metering factors.
From page 24...
... , and splits will be provided that are proportional to the volume-to-saturation ratios of each phase, subject to minimum green times. The yellow and red clearance times entered in the Signal Timing fields (callout iv)
From page 25...
... The next two rows show the saturation flow rate for the movement in units of veh/h/ln and veh/h. The saturation flow rates are carried over from the Site worksheet for the relevant approach.
From page 26...
... The intersection layout, volumes, and signal timing are presented in Figure 11. This is a hypothetical scenario selected with different right-turn configurations on each approach to facilitate a comparison of model results.
From page 27...
... The estimated RTOR volume is a reduction from the original unadjusted volumes. The eastbound approach is a shared through and right-turn lane configuration.
From page 28...
... 3.7 Implementation of RTOR Models in the HCM Computational Engine The spreadsheet tool is limited to a small number of intersection configurations. To mitigate these limitations, the RTOR volume models were also incorporated into the HCM Computa tional Engine.
From page 29...
... Figure 12. Location of RTOR volumes on the Operations worksheet.
From page 30...
... Figure 13. HCM Computational Engine: "RTOR" Worksheet added to the spreadsheet.
From page 31...
... 3.7.2  Description of Procedure To use the RTOR volumes, use the following steps: 1. In the RTOR sheet, be sure that the green cell for "Signal Timing Source" is set to "Maximums." 2.


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