The Relationship Between Transit Asset Condition and Service Quality (2018) / Chapter Skim
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35 Using the EJT Calculation Tools This chapter provides step-by-step instructions for using the Effective Journey Time (EJT) Calculator developed through the research and accompanying this report.
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36 The Relationship Between Transit Asset Condition and Service Quality Chart for Selected Scenarios contain charts reflecting the results of the analysis. The sections Summary Results by Fleet Age, Summary Results for Selected Scenarios, Detailed Calculations by Fleet Age, and Detailed Calculations for Selected Scenarios contain tables displaying the results of the analysis.
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Using the EJT Calculation Tools 37 4. Enter the Route length.
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38 The Relationship Between Transit Asset Condition and Service Quality 1. Enter the Headway standard deviation.
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Using the EJT Calculation Tools 39 Summary Results by Fleet Age The Summary Results by Fleet Age section shows the effects of fleet age on different journey time components that make up the total EJT. The total EJT for each scenario is broken down by its components: Buffer, Wait, and In-Vehicle time.
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40 The Relationship Between Transit Asset Condition and Service Quality • Effective Journey Time – Wait is the number of minutes a passenger spends waiting for vehicle arrival. • Effective Journey Time – In-Vehicle is the number of minutes a passenger spends in a vehicle.
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Using the EJT Calculation Tools 41 • Failure Rate is the number of vehicle failures predicted per mile (inverse of MDBF)
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42 The Relationship Between Transit Asset Condition and Service Quality • Revised Considering Spare Availability – Failure Delay is the delay per passenger due to vehicle failure revised to consider the percentage of vehicles under repair. • Revised Considering Spare Availability – Headway SD is the variation in headway data revised to consider the percentage of vehicles under repair.
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Using the EJT Calculation Tools 43 • Future Advanced Parameters: Edit details concerning in-station conveyance and guideway segments for the two defined future scenarios. Summary The Summary section displays tables and charts comparing base conditions to those of future typical, future worst case, and future average scenarios.
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44 The Relationship Between Transit Asset Condition and Service Quality details (e.g., number of seats per vehicle, average fleet age, and in-vehicle comfort factor) further help to define the vehicle parameters.
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Using the EJT Calculation Tools 45 2. Enter the Vehicles per consist.
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46 The Relationship Between Transit Asset Condition and Service Quality 3. Enter the Direction 2.
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Using the EJT Calculation Tools 47 number of guideway segment rows. The default value is 50.
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48 The Relationship Between Transit Asset Condition and Service Quality Figure 6-17 shows a partial view of the Advanced Parameters worksheet. (Not shown in the screenshot is the table for entering guideway parameters.)
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Using the EJT Calculation Tools 49 1. Enter the Comfort factor for vehicle in poor condition.
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50 The Relationship Between Transit Asset Condition and Service Quality 1. Enter a Delay per passenger on a failed vehicle.
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Using the EJT Calculation Tools 51 5. Enter an Elevators/Escalators Failure Probability for each station.
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52 The Relationship Between Transit Asset Condition and Service Quality Fixation Track, and Guideway -- Tangent Embedded Track. The default value for this parameter is calculated from the Guideway type selected on the Base Case Parameters worksheet.
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Using the EJT Calculation Tools 53 • In practice, one can define the future case however one desires, and it is not necessary to define both the worst case and typical case. • Depending on how dire the future case is, some of the parameters assumed in the base case may or may not be realistic.
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54 The Relationship Between Transit Asset Condition and Service Quality by Typical Case is calculated from the Percentage of time represented by Worst Case described in the previous section and cannot be overridden. The base case parameter values are shown alongside the default values for each parameter.
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Using the EJT Calculation Tools 55 Parameters and Guideway Parameters for each of the future cases, with the worst case parameters presented first and the typical case parameters following. The Station Names and Guideway Segments contain values calculated from input cells on the Base Case Parameters worksheet.
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56 The Relationship Between Transit Asset Condition and Service Quality from input values entered on the Base Case Parameters worksheet and should not be edited on this worksheet.
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Using the EJT Calculation Tools 57 3. Enter the Guideway Comfort Factor for each guideway segment.
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58 The Relationship Between Transit Asset Condition and Service Quality Similar to the Base Case Parameters worksheet, these parameters are organized by station and direction. This section contains default values that are entered on the Base Case Parameters and Advanced Parameters worksheets.
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Using the EJT Calculation Tools 59 Figure 6-30. Summary results worksheet.
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60 The Relationship Between Transit Asset Condition and Service Quality • Buffer Time is the number of minutes that a passenger must add to travel time when planning a trip to ensure on-time arrival. • In-Station Conveyance Time is the number of minutes a passenger spends traveling through stations.
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Using the EJT Calculation Tools 61 Percent Change The Percent Change section shows the percent change in Buffer Time, In-Station Conveyance Time, Waiting Time, In-Vehicle Time, and Effective Journey Time for future scenarios relative to the base case scenario. The results are presented in both adjusted and unadjusted terms.
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62 The Relationship Between Transit Asset Condition and Service Quality • Effective Journey Time is the total EJT per passenger. The EJT is the total amount of time a passenger is in transit and is the summation of the following components: Buffer Time, In-Station Conveyance Time, Waiting Time, and In-Vehicle Time.
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Using the EJT Calculation Tools 63 advanced parameters, the results should be the same as those shown in Figure 6-37. This table shows the components of journey time (buffer, wait, and IVT)
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64 The Relationship Between Transit Asset Condition and Service Quality 10.5 13.8 11.4 10.5 21.8 28.6 23.8 21.8 15.0 19.3 18.2 17.2 0 10 20 30 40 50 60 70 New Fleet Aged 10 Years Aged 5 Years Base Case Effective Journey Time per Passenger (min) Buffer Time Wait Time In-Vehicle Time Figure 6-38.
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Using the EJT Calculation Tools 65 Figure 6-39. Map of Central Line.
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66 The Relationship Between Transit Asset Condition and Service Quality Figure 6-40. Main menu of EJT calculator.
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Using the EJT Calculation Tools 67 Parameter Description Value Number of stations/stops 12 Direction 1 Northbound Direction 2 Southbound Annual unlinked passenger trips 6,000,000 Average vehicle headway (minutes) 9.0 Typical trains/buses per day (enter by station in advanced parameters)
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68 The Relationship Between Transit Asset Condition and Service Quality Figure 6-41. Adjust station list button.
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Using the EJT Calculation Tools 69 additional 5 years, while the "typical" scenario will be used to calculate the benefit of improving the track and replacing the fleet. Finally, select the tab in the spreadsheet for "Future Advanced Parameters" and, for the future typical case, change the average travel time from Grand Central to Penn Station from 5 minutes to 2 minutes.
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70 The Relationship Between Transit Asset Condition and Service Quality the track would reduce EJT to 23.4 minutes. Much of this reduction stems from the predicted change in IVT from eliminating the slow zone between Penn Station and Grand Central, as well as from improving the fleet.
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