1. Planning Process Types of Studies yTrend Line yAllocation Model ySmall Urban yMPO yRegional

2. Process - Types of studies Trend Line Study zVery small urban areas or counties zLittle growth anticipated zNo new thoroughfares expected zTrend line projections of past traffic counts

3. Process - Types of studies Travel Allocation Model zPopulation < 5,000 zGrowth anticipated zNew facilities anticipated zAllocation approach

4. Process - Types of studies Small Urban Study zPopulation between 5,000 and 50,000 zArea that has anticipated growth zArea has current TIP project zPerceived need for new location facilities z“Sketch” travel model

5. Process - Types of studies MPO Study zNeed to answer more policy related questions zGrowth communities zMultiple transportation alternatives zNeed to perform air quality analysis zTravel Demand Model

6. Process - Types of studies Regional Study zComplex, cross jurisdictional policy issues zLarge multi-modal investments zRegional travel flows and facilities zNon-traditional travel models - state of the practice

7. Planning Process Travel Allocation Models as a Tool

8. Process - Allocation Model Why an Allocation Model? zNew transportation facilities are anticipated zBase and future travel patterns needed to: yassist in location decisions ydetermine design requirements yevaluate user benefits of proposed improvements

9. Process - Allocation Model Benefits of an Allocation Model Can produce estimates of existing and future travel patterns in a fast, low cost, and easy to apply manner. Teaches the general concepts of transportation planning and travel modeling.

10. Process - Allocation Model Step 1: Define Planning Area and Traffic Zones

11. Process - Allocation Model Step 2: Estimate existing and future population zStep down approach: ycounty ytownship yplanning area zUse OSBM or projection from past trends for future year totals

12. Process - Allocation Model Step 3: Estimate external and through trips for external stations zAverage daily traffic zUse local knowledge or OD survey to estimate percent through trips

13. Process - Allocation Model Step 3: Example

14. Process - Allocation Model Step 4: Estimate trips generated by population and development zEstimate persons per dwelling zEstimate trip generation rate zEstimate commercial vehicle trips as a percent of dwellings

15. Process - Allocation Model Step 4: Example

16. Process - Allocation Model Step 5: Account for trips made by residents leaving the area zBased on knowledge of planning area and surrounding area determine the number of residents and CVs that will have destinations external to the planning area

17. Process - Allocation Model Step 5: Example

18. Process - Allocation Model Step 6: Account for non-home based trips made by non-residents zNon-residents with destinations in the planning area often make additional trips while in the area zPercentage based on knowledge of area or old survey data

19. Process - Allocation Model Step 6: Example

20. Process - Allocation Model Step 7a: Develop trip tables zThrough trips - NCHRP 365 or old survey data zA stick line sketch will help with estimation

21. Process - Allocation Model Step 7b: Develop trip tables zEI trips allocated to internal zones based on relative trip attractiveness judged by knowledge of land uses in zones

22. Process - Allocation Model Step 7c: Develop trip tables zInternal trips are also distributed based on relative attractiveness zZone-to-zone distribution and intra-zonal distribution

23. Process - Allocation Model Step 8: Assign base year trips and check against ground counts zManually assign trips to the major street system and validate against traffic counts zThis process will provide analyst with a systematic understanding of the traffic flows zUsing different colors for the different trip types is useful

24. Process - Allocation Model Step 9: Assign future year trips and evaluate alternatives zAn understanding of traffic flows from base year allocation will lead the analyst to a clearer understanding of future year deficiencies

25. Wrap-Up Questions?