Transportation Alert:
A Comprehensive Transportation Analysis (CTA) is a tool used by transportation practitioners to study the impacts of proposed changes to a transportation system or planned land use. Where transportation studies of the past focused primarily on traffic impacts, the CTA provides a more balanced approach: identifying the benefits and drawbacks a proposal could bring to pedestrian, bicycle, transit and vehicle travel. Fairfax County utilizes Comprehensive Transportation Analyses to implement strategic goals for improved mobility and transportation for all users.
There are three broad study types that may utilize a CTA:
CTAs also are used to supplement VDOT Traffic Impact Analyses (TIA). The number of average daily trips a proposal generates will dictate the type of study required for zoning actions and SSPAs. See the table below for a summary of the different CTA Tiers.
| Comprehensive Transportation Analysis versus VDOT Traffic Impact Analysis | |||
| Tier2 CTA | Tier 3 CTA | TIA | |
| When is a transportation analysis triggered? | Required for proposed developments that generate more than or equal to 1,000 but less than 3,000 Average Daily Trips (ADT) | Required for proposed developments that generate more than or equal to 3,000 but less than 5,000 Average Daily Trips (ADT) | Required for proposed developments that generate more than or equal to 5,000 Average Daily Trips (ADT) |
| Scoping | Requires a scoping meeting with FCDOT and VDOT. Needed before study is conducted. | ||
| Review Timeframe | Review Timeframe of 45 days for the first submission and 30 days for subsequent submissions. | ||
| Final Approval | FCDOT | FCDOT | VDOT |
| Fee | None | None | Processing Fee Payabe 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.
CTAs are conducted by FCDOT staff or transportation consultants. The analysis produced through a CTA is reviewed by FCDOT staff, VDOT staff when applicable, and interpreted for the general public, public officials and other stakeholders for use in the decision-making process for a project or plan.
A CTA can be used anywhere within Fairfax County. The framework of the CTA is based on Fairfax County’s Concept for Future Development Map. The CTA groups similar land area types, such as urban centers and transit station areas, and notes which modes (e.g. walking, biking, using transit, driving) should be prioritized. However, the CTA process acknowledges that no two places in the County are alike, and it is important to understand the specific needs of a community during the scoping of a study.