COG/TPB Transportation Analysis Zone (TAZ) Update Project

1. COG/TPB Transportation Analysis Zone (TAZ) Update Project Robert E. Griffiths Presentation to the TPB Scenario Study Task Force April 16, 2008

2. A brief overview of objectives • Key objective- balance the needs of transportation modeling and forecasting future land activity (Cooperative Forecasting) • Smaller zones around activity centers, transit, areas of increased or planned development • Strive for uniformity in zone size throughout the COG/TPB Modeled Region ,taking into account development patterns (present and future) • Design a new zone structure that will be usable and meaningful until the next TAZ update (10-15 years historically) • Rough estimate - double the current number of zones currently used; may vary by jurisdiction

3. Example #1, continuedArlington County, VA Incorporate splits of existing zones provided by Arlington County; alignment with COG Regional Activity Centers where possible 82 current TAZ, both COG/TPB and Arlington County Proposed: 109 COG/TPB TAZ for Arlington County. This is an increase of 25 zones.

4. Example #1, continuedBallston Metro Station Area For the Ballston Metrorail Station Area, the new TAZ system will break 2 current TAZs into 5 smaller ones The new TAZs will better delineate higher density mixed use zones from lower density residential areas Creates a new TAZ for Ballston Commons

5. Example #1, continuedShirlington Also in the Shirlington area, the new TAZ will better delineate higher density mixed-use areas from lower density residential areas.

6. Example #2Prince George’s County, MD • The current COG/TPB TAZ system for Prince George’s County has 381 zones • Smaller zones inside the Beltway • Larger zone sizes outside the Beltway • The proposed, draft number of COG/TPB TAZ’s for Prince George’s County is currently 649 • This is an increase of 269 zones for the county

7. Example #2, continuedLargo Activity Center Seventeen new smaller TAZs will used to better define the Largo Activity Center. Four new TAZs will be created in the immediate vicinity of the Largo Metrorail station from one large current TAZ.

8. Example #3Prince William County, VA Currently, there are 142 COG/TPB TAZ’s for Prince William County. The new proposed number of COG/TPB TAZ’s for Prince William County is 367 zones. This is an increase of 225 zones.

9. Example #3, continuedInnovation Activity Center The Innovation Activity Center in Prince William County is currently defined by only 3 large TAZs The 10 new TAZs for the Innovation Activity Center will better identify more concentrated areas of projected employment growth.

10. New Data for New TAZs • 2007 Household Travel Survey • Spring 2007 Metrorail Survey • Fall 2007 Air Passenger Survey • Spring 2008 Regional Bus Survey • “Round 8” Cooperative Forecasts

11. Project Schedule • New TAZ Structure – June 30, 2008 • Geocoded Survey Data – December, 2008 • Revalidated Transportation Model (2191-TAZ) – Spring, 2009 • New Highway and Transit Networks – early Fall, 2009 • Preliminary “Round 8” TAZ-level Forecasts – Fall, 2009 • Recalibrated Transportation Model (New TAZs) – late Fall, 2009 • Draft “Round 8” Forecasts – early 2010 • Major CLRP Update – Spring 2010

12. New Status Report by Jurisdiction

13. Status report by jurisdiction, continued