E. 131st Avenue PLAT Study

Analytical Travel Forecasting Approaches for Project-Level Planning and Design

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Table 6-2. Description of fields in spreadsheet.

Column Variable

Definion

1

Road/Link

The name/route number of each facility bisected by the screenline and/or the link numbers from network. Minimum Count/Model Rao for using differences, below this use raos alone. Maximum Count/Model Rao for using raos, above this use differences alone. Set to "Enable" to allow use of screenline adjustments for this leg. If no count available, set to "Disable" to disable giving no adjustment of model result. Set to "Force" to force SL adjustment

2

Min Diff

3

Max Rat

3.5

Use SL

4 5 6 7

COUNT Year

Year of the actual base year traffic count.

COUNT

Actual base year traffic count.

Ab

Base year traffic assignment—user to input year.

Ab interpolate

Interpolaon between base and future year assignment—used when year of count data differs from base year assignment. If opening year no build exists, use opening year no build to base year interpolaon. If opening year no build does not exist, use design year to base year interpolaon.

7.1 7.2 7.3 7.4

R D

Calculated Rao (COUNT/Ab).

Calculated Difference (COUNT Ab).

MR SLR

Model Rao (Af - D/Ab).

Screenline Rao ( Count/ Ab). Future year traffic assignment Af D: (near) design year model run.

8

Af

Af ON: (near) opening year no build run (oponal) Af OB: (near) opening year build model run (oponal). Adjusted future year traffic forecast ( Count/ Ab)*Af. Adjusted future year traffic forecast (COUNT/Ab) * Af. Adjusted future year traffic forecast (COUNT Ab) + Af. Adjusted future year traffic forecast. Modified "rao method" to weight towards DIFF method for large model increases. If MR < 1 then MRATIO = RATIO. else MRATIO = ((MR 1)*DIFF + RATIO)/MR. Adjusted future year traffic forecast (AVERAGE[MRATIO,DIFF]). Selects the type of future year adjustment based on the rao of actual base year traffic count to interpolated base year traffic assignment. If MR < 1 then

8.5

SLRATIO

9

RATIO

10

DIFF

10.5

MRATIO

11 12

RAf

Selected Adjustment

if RATIO 1.0 then use RATIO, if RATIO 2.0 then use DIFF, else use RAf, If MR > 1 then if RATIO 0.5 then use MRATIO, if RATIO 2.0 then use DIFF, else use RAf (based on MRATIO)

13 14

Selected Volume Selected adjusted forecast year model volume

Most Recent Count Year

Year of the most recently available actual count data (should be less than opening year. If opening year is same as base year, then generally will not use). Most recently available actual count data for the facility.

15

Most Recent Count Data

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