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Transportation Analysis

An important aspect of reviewing changes in land use through the entitlement process is the transportation analysis. This analysis provides information to assist in the review of a land development application by helping to understand the transportation needs and impacts of each application with respect to its users and the surrounding community. Transportation analyses regarding zoning proposals at Fairfax County exist in four forms: Tier 1 Transportation Statement, Tier 2 Comprehensive Transportation Analyses-Zoning (CTA-Z), Tier 3 Comprehensive Transportation Analyses-Zoning (CTA-Z), and Chapter 870 Traffic Impact Analyses (TIA). The following guidance should be used by applicants submitting requests for entitlement or amendments to existing entitlements, or if otherwise requested by the Fairfax County Department of Transportation (FCDOT). If you are looking for information on Transportation Analyses related to Site-Specific Plan Amendments (SSPA), visit the Transportation Analyses for SSPA page.

A Tier 1 Transportation Statement provides supplemental transportation information for use in the review of an entitlement application. It is required for all applications that generate 999 or fewer average daily trips (ADT). View and complete the Transportation Statement template.

A Comprehensive Transportation Analysis-Zoning (CTA-Z), formerly known as Operational Analysis, is an analysis that helps identify the transportation impacts of a development proposal and evaluate mitigations necessary to facilitate a proposed change in land use consistent with the County’s guiding plans and policies. These CTA-Zs document and analyze:

Existing conditions of multimodal facilities.
Future conditions without development (background)
Future conditions with development (total future) which include the vehicular and non-vehicular trips generated from the proposed change.

With consideration for the surrounding area, a CTA-Z seeks to assess impacts for multiple modes of transportation from a proposed change in land use, including cycling, walking, riding public transit, and driving. There are two tiers of a CTA-Z that are determined based on trip generation. A Tier 2 CTA-Z is an analysis conducted for developments that generate between 1000 and 2999 ADT while a Tier 3 CTA-Z is an analysis conducted for developments that generate between 3000 and 4999 average daily trips (ADT). A Tier 2 CTA-Z and Tier 3 CTA-Z both contain the same parameters that focus on multimodal transportation. For the vehicular analysis, Tier 2 studies include the site access points and any intersections along the site perimeter while Tier 3 studies include both site access points and relevant off-site intersections.

The outcome of these analyses guide recommendations for transportation improvements associated with the application. While these studies are requested by FCDOT, they are scoped and reviewed in coordination with the Virginia Department of Transportation (VDOT). For more information on the specific expectations for CTA-Z’s please see the Comprehensive Transportation Analysis Checklist.

A Chapter 870 Traffic Impact Analysis (TIA) seeks to assess the transportation impacts of a proposed change in land use that is forecasted to generate at least 5,000 average daily trips (ADT). TIA’s are required by VDOT in accordance with the Virginia Administrative Code. Like a CTA-Z, a TIA also documents the transportation impacts of existing conditions, future conditions without development (background), and future conditions with development (total future) which takes into consideration the trips generated from the proposed change.

Elements included in a CTA-Z can also be assessed in a TIA; the main elements considered in TIAs include vehicular level of service (LOS), queuing, delay, access management, and intersection spacing. While TIAs requirements are determined by VDOT, applicability to a specific application is determined by FCDOT. TIAs are scoped and reviewed by VDOT in coordination with FCDOT.

COMPREHENSIVE TRANSPORTATION ANALYSIS-ZONING VS CHAPTER 870 TRAFFIC IMPACT ANALYSIS

	Tier 1 Transportation Statement	Tier 2 CTA-Z	Tier 3 CTA-Z	TIA
When is a transportation analysis triggered?	Required for proposed developments that generate 999 or fewer Average Daily Trips (ADT)	Required for proposed developments that generate ≥ 1,000 but fewer than 3,000 Average Daily Trips (ADT)	Required for proposed developments that generate ≥ 3,000 but fewer than 5,000 Average Daily Trips (ADT)	Required for proposed developments that generate ≥ 5,000 Average Daily Trips (ADT)
Scoping	N/A	Requires a scoping meeting with FCDOT and VDOT. Needed before study is conducted.
Review Timeframe	N/A	Review Timeframe of 45 days for the 1st submission and 30 days for subsequent submissions
Final Approval	N/A	Fairfax County DOT	Fairfax County DOT	VDOT
Fee	N/A	N/A	N/A	Processing Fee Payable to VDOT

Note:

Average Daily Trips are the net increase in trips generated by the proposed developments when compared to trips generated by the by-right use.
At the time of final approval, the applicant will receive the CTA-Z approval notice via email from FCDOT and the TIA approval notice via email from VDOT.

Per Section 24VAC30-155 of the Virginia Administrative Code, each applicant shall request a determination by FCDOT during application acceptance to assess whether the proposal requires a TIA. If a TIA is not warranted, a CTA-Z may be required in accordance with county policy. FCDOT also reserves the right to request additional analyses if determined to be needed during application review. Refer to this flow chart to help determine if your development requires a CTA-Z or TIA. Use the fillable Transportation Determination Request form to submit your request.

If FCDOT determines a Tier 2 CTA-Z, Tier 3 CTA-Z, or TIA is required, the applicant’s transportation consultant will need to prepare a Pre-Scoping Form outlining assumptions and supplemental information to be included in the transportation analysis. Access the Traffic Impact Analysis (TIA) Scoping Form and the Coordinated Traffic Analysis Zone (CTA-Z) Scoping Form. Once prepared, the applicant should request a scoping meeting through FCDOT. The scoping meeting provides an opportunity for all parties to provide input and comment on the proposed transportation analysis. After the pre-scoping form is signed and approved by FCDOT and VDOT, the applicant may begin preparing the Tier 2 CTA-Z, Tier 3 CTA-Z, or TIA.

The applicant must provide an electronic submittal of the CTA or TIA via email to both FCDOT and VDOT with review timelines commencing upon confirmation of receipt by VDOT. Hard copies should be provided only if requested by FCDOT or VDOT.

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WHAT IS A TRANSPORTATION STATEMENT?

WHAT IS A COMPREHENSIVE TRANSPORTATION ANALYSIS-ZONING (CTA-Z)?

WHAT IS A CHAPTER 870 TRAFFIC IMPACT ANALYSIS (TIA)?

HOW IS THE APPROPRIATE TRANSPORTATION ANALYSIS DETERMINED?

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