1 Common Procedures For Small Area Forecasting Justin Clarke, Arlington County Mubarika Shah, Fairfax County Greg Goodwin, COG Staff Metropolitan Washington Council of Governments Cooperative Forecasting and Data Subcommittee Small Area Task Force May 4, 2004

2 Participants Information and materials included in this presentation were prepared by other members of the Small Area Task Force: –Mayra Bayonet, City of Rockville –Robert Beasley, District of Columbia –Gary Fuller, City of Falls Church –Philip Taylor, Prince George's County - M-NCPPC –Jim Wasilak, City of Rockville

3 Why are we doing this? Educational Process Preparation for the Round 7 Technical Report Small Area (TAZ) Forecasting consistency among the member jurisdictions

4 l Questions Asked l List of Common Items l Special session of Round Table Discussion l Compilation and refinement How do we do it?

5 Findings/Strengths: Time Frame Base Year Date –Population and Households: April 1, 2000 –Employment: March 2000 (End of First Quarter) Year 2000 average sometimes necessary based on source data Extent of Forecasts –Data prepared in 5 year increments for 30 years from Base Year For Round 7: 2000 to 2030

6 Findings/Strengths: Area Systems (Geography) Jurisdictional totals COG Traffic Analysis Zones (TAZ) –using the “2191 Zone” or “Expanded Cordon” Transportation Planning Board (TPB) zone system Typical procedures to obtain TAZ level data: –Aggregation of TAZ data to a jurisdictional total –Translation of planning area or Census geography data to TAZ level figures –Disaggregate a total figure down to TAZ allotments

7 Next Steps Employment –Standardize base month (3/00, 3/05, 3/10, 3/15) –Standardize allocation of sectors with COG employment categories (Office, Retail, Industrial…) –Establish grouping of sectors to respond to Regional Reports and Econometric Model –Provide an allocation guide consisting of a list of sub categories of employment types such as home based employment –Determine how to control the double counting of jobs at the TAZ level (continued)

8 Next Steps (Continued) Other Items –Establish a self check control method for long term forecasts such as a “Top Down Methodology” –Decide when to use 2005 as a Base Year (Round 7.1, 8?) –Review “2191” geography limitations and improve boundary locations where possible Coordinate with appropriate COG staff and TPB Technical Committee –Alternative Scenarios: review need for jurisdictional level scenarios

9 Feedback from committee Present Draft Report/Findings to the Cooperative Forecasting and Data Subcommittee - May Meeting Receive written/oral comments from other members of the committee by the June Meeting Incorporate new comments into final report – ready for distribution at the July meeting