Wells + Associates’ team of traffic engineers, transportation planners, and traffic designers is a leader in providing transportation consulting services in Fairfax County to developers, property owners and managers, communities, and other professional organizations.

Out of our home base in Tysons, Virginia in Fairfax County, we provide a range of services, including:  

• Traffic Impact Analyses for Fairfax County Developments 
• Parking Analyses, Parking Reduction, and Shared Parking Studies in Fairfax County 
• Multimodal Transportation Planning for Mixed-Use, Transit-Oriented, and Affordable Housing Developments 

Traffic Impact Analyses for Fairfax County Developments

Our traffic engineers are well versed in creating traffic impact analyses for projects in Fairfax County.  

Developments in Fairfax County that involve changes in land use through the entitlement process require transportation analysis. In 2025, the Fairfax County Department of Transportation (FCDOT) updated its process to establish four levels of analysis based on the number of net new average daily trips (ADT) generated by a proposed development:

• 999 or fewer net new ADT: Tier 1 Transportation Statement
• 1,000–2,999 net new ADT: Tier 2 Comprehensive Transportation Analysis-Zoning (CTA-Z)
• 3,000–4,999 net new ADT: Tier 3 Comprehensive Transportation Analysis-Zoning (CTA-Z)
• 5,000 or more net new ADT: VDOT Chapter 870 Traffic Impact Analysis (TIA)

Because the thresholds are based on net new trips, the transportation analysis required for a redevelopment may depend on the difference between trips generated by the proposed development and those associated with the property’s by-right use.

For development applications involving rezoning, proffer condition amendments, special exceptions, special permits, and other entitlement actions, FCDOT determines the appropriate level of transportation analysis based on the proposed development and its anticipated net new trips.

For projects requiring a Tier 2 CTA-Z, Tier 3 CTA-Z, or Chapter 870 TIA, the applicant’s transportation consultant participates in a scoping process with FCDOT and VDOT before preparing the study. Establishing the study parameters early helps the development team understand the transportation issues and analyses that will need to be addressed as the entitlement process moves forward.

Our Fairfax County traffic engineers and planners are also uniquely qualified to help during Fairfax County’s biannual Site-Specific Plan Amendment (SSPA) Process. We can accurately estimate vehicle trips for existing and proposed conditions that account for changes in density or program mix. An explanatory infographic of the SSPA Process is here.

Learn more about Fairfax County’s updated transportation analysis requirements in our article, Does Your Fairfax County Development Project Need a Traffic Impact Analysis? Part 1: Understanding CTA-Z Tiers 1 and 2. You can also watch our video about traffic impact analyses for Fairfax County developments.

Selected Fairfax County Traffic Impact Analysis Case Studies:

Inova Fairfax Medical Campus: Traffic Study for Hospital Expansion 

Metro West: Traffic Impact Study for Model Fairfax County TOD Project 

Tysons Corner Center: Traffic Impact Study of Proposed Redevelopment 

Parking Analyses, Parking Reduction, and Shared Parking Studies in Fairfax County

Off-street parking is regulated in Fairfax County to ensure that adequate parking is available for commuters and residents. While building adequate parking remains a concern, Fairfax County is recognized as a leader in developing solutions to “right-size” parking – in other words, not building more parking (which is expensive) than is necessary.  

W+A has been at the forefront of the trend of reducing the need for parking through the development of intelligent transportation networks and solutions, including:  

• developing shared parking plans 
• developing and implementing TDM and mobility management programs 
• managing last-mile connections for transit-adjacent properties, and  
• developing active transportation and multimodal options  

In short, parking is expensive for developers to build, and these costs are passed on to tenants. Our work in developing forward-thinking parking studies and analyses for a wide range of developments has helped developments and communities in Fairfax County reduce parking while boosting transportation choices and avoiding increases in vehicular traffic congestion.

Business owners in Fairfax County may be told by the county that they need to determine new levels of parking requirements at your place of business. This often happens when there is a change or an expansion in land use that requires a greater need for parking. You can learn more about How to Update Your Parking Tabulation Form for Fairfax County here. 

Selected Fairfax County Parking Analysis Case Studies

Reston Town Center: Traffic Impact and Parking Reduction Studies 

In A Costly Real Estate Development Market, Don’t Overbuild Parking: Take Advantage of Parking Reductions for Your Property

Multimodal Transportation Planning for Mixed-Use, Transit-Oriented, and Affordable Housing Developments

Due to increasing urbanization and density, the need for more housing, land use and zoning modifications, the rise in population and vehicular traffic, and more, our team has been at the forefront of developing transportation solutions for mixed-use developments, transit-oriented developments, and, notably, projects in the unique “edge city” of Tysons in the heart of Fairfax County.  

Mixed-Use Developments

Regional centers throughout the county that formerly were auto-oriented and single land use destinations have been rezoned to mixed use, including office, retail, and residential. We have been at the forefront of these developments, working with developers, county officials, and professional peers in transportation charettes and studies. Our solutions have included the development of a wider range of transportation choices (including transit, active transportation, ride-hailing, and shuttles), right-sizing parking, reducing vehicle trips through TDM programs, community engagement, and developing traffic design solutions.  

Transit-Oriented and Transit-Adjacent Developments

The expansion of transit choices in Fairfax County has enabled developments to take new approaches to how people get to and get around their communities. Our traffic analyses, parking studies, TDM plans, geospatial analyses, and transportation planning recommendations have enabled transit-oriented developments to create walkable communities and transit-adjacent buildings and complexes to develop last-mile connections.   

Affordable Housing

As Fairfax County continues to increase in density, the issue of affordable housing has become a more acute concern. Workers need to be able to access workplaces closer to home, while businesses depend on a committed workforce. Affordable housing developments raise various transportation concerns, including parking availability, the potential increase in vehicular traffic, and the need for a variety of transportation options for tenants. Our team provides traffic engineering, parking, transportation planning, and multimodal transportation analyses to ensure that affordable housing in Fairfax County’s landscape has multimodal access to jobs, recreation, and shopping.  

Selected Case Studies:

One University: Parking Analysis for Affordable Housing in Fairfax 

Metro Orange Line: TDM Plan and Traffic Impact Study for Model Fairfax County TOD Project