COG/TPB Transportation Analysis Zone

(TAZ)Update Project

Robert E. GriffithsPresentation to the

TPB Scenario Study Task Force

April 16, 2008

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

Example #1, continuedArlington County, VA

82 current TAZ, both COG/TPB and Arlington County

Incorporate splits of existing zones provided by Arlington County; alignment with COG Regional Activity Centers where possible

Proposed: 109 COG/TPB TAZ for Arlington County. This is an increase of 25 zones.

Example #1, continuedBallston Metro Station

AreaFor 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

Example #1, continuedShirlington

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

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

Prince George's County TAZ

DRAFT Prince George's County TAZ (649)

COG/TPB Prince George's TAZ (381)

Activity Centers

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.

Example #3Prince William County, VA

COG/TPB TAZ,before and after

DRAFT COG PWC TAZ's (367)

Current COG TAZ's (142)

Regional Activity Centers

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.

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.

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

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

New Status Report by Jurisdiction

COG Member jurisdictions  Name Status Remarks

  District of Columbia

Preliminary meeting held

Working within DC's schedule for addressing

TAZ updates

 Montgomery County, MD (including Gaithersburg, Rockville, Takoma Park)

County staff performing internal

updates Will acquire new

updates from county

 

Prince Georges County, MD (including Bladensburg, Bowie, College Park, Greenbelt)

Proposed COG/TPB changes sent

Currently under review by county

  Arlington County, VAProposed COG/TPB

changes sentPending final approval

from county

  City of Alexandria, VAMeeting dates to be

scheduled Next up on schedule

 Fairfax County, VA (including Falls Church and City of Fairfax)

Meeting dates to be scheduled Next up on schedule

  Loudoun County, VAPreliminary meeting

held Next meeting date TBD

 Prince William County, VA (including Manassas and Manassas Park)

Proposed changes sent; pending final

approval from countyCurrently under review

by county

 Frederick County, MD (including City of Frederick) Meeting date TBD  

BMC jurisdictions      

  Howard County, MDProposed COG/TPB

changes sentAwaiting response from

BMC

  Anne Arundel County, MDProposed COG/TPB

changes sentAwaiting response from

BMC

  Carroll County, MDProposed COG/TPB

changes sentAwaiting response from

BMC

Status report by jurisdiction, continued

Tri County Council for Southern MD (TCC) jurisdictions:  Name Status Remarks

  Charles County, MD

Proposed COG/TPB changes sent; reviewing comments from county

Pending final approval from county

  Calvert County, MDProposed COG/TPB

changes sentPending final approval from

county

  St. Mary's County, MDZones completed & approved by county

Awaiting additional data for comparison

FAMPO jurisdictions      

  King George County, VACOG staff to coordinate

with GWRC  

  City of Fredericksburg, VACOG staff to coordinate

with GWRC  

  Stafford County, VACOG staff to coordinate

with GWRC  

  Spotsylvania County, VACOG staff to coordinate

with GWRC  

Additional COG/TPB Modeled Region Jurisdictions      

  Fauquier County, VA Meeting date TBD  

  Clarke County, VA Meeting date TBD  

  Jefferson County, VAProposed COG/TPB

changes sentAwaiting proposed

changed from county