Development Challenges to Address

If the projected beneficial impacts of Warner Brook warrant further consideration, then potential challenges must also be considered. There are three areas related to development that all citizens should question: Traffic, Expenses, and Phasing.


Traffic is the primary negative impact of any growth, even from the smallest infill project or redevelopment. Traffic needs to be evaluated from the standpoint of what roads will be impacted, what is the current daily volume on those roads, what is the maximum capacity of those roads as they are currently designed and constructed, what is current volume as a percentage of maximum capacity, and what is the increased trip volume projected from the uses of the proposed development.

The other aspect of traffic study and planning is at what point during the planning process does detailed traffic study, problem specification, and solution approval take place. Once annexation is approved and Warner Brook is brought into the Town under temporary Transition X zoning, nothing can take place until an application for rezoning for specific uses is submitted to the Town. During that process, traffic impact for each applied use is studied in detail, whereupon the Town and citizens have control over what gets approved, including traffic plans.

Even though detailed traffic study and solutions would be addressed at the rezoning application stage, it is appropriate now to identify traffic impact as an item that citizens want to address during rezoning. Warner Brook has undertaken two initial traffic studies. Most recently in the fall of 2017 automatic traffic recorders (ATR) were placed on the roads that would be impacted, for purposes of quantifying their current daily traffic volume. The traffic study then factored their VDOT designed capacity, and projected Warner Brook incremental volume impact. The primary roadway links impacted by Warner Brook are Berlin Turnpike, Hirst Road, North Hatcher Avenue, and Purcellville Road.

Existing Volume

ATR Locations and Daily Traffic Volumes (2017)ATR locations


Table 1: Existing Traffic Volumes (2017) SummaryTable 1

Roadway Capacities

As requested by the Town staff, the capacities of the roadways in the study area were estimated and are presented in this section. The roadway characteristics and peak hour traffic volumes were entered into HCS 2010 software to determine the roadway capacities. The software calculates the capacities based on the methodology in the Highway Capacity Manual 2010 (HCM 2010). Table 2 summarizes the capacities and the volume to capacity (v/c) ratios for the roadways in the study area.

An evaluation of the capacity revealed a capacity of approximately 1,700 vehicles per hour in each direction for all the roadways. Based on the volumes observed on Hirst Road, North Hatcher, and Purcellville Road roadways, there is adequate capacity on these roadways during both the peak hours. Moreover, there is surplus capacity on these roadways, which would be able to accommodate additional traffic to the Town.

Berlin Turnpike between Rt. 7 and Hirst Road appears to have afternoon peak volume already at 88% of existing capacity. This needs addressing now, whether or not Warner Brook is developed in the future.

Loudoun County does have an improvement project for this intersection in the six-year Capital Improvement Program. Funding isn’t available until FY19, so study and design work will not begin until after July 1, 2018.


Table 2: Roadway Capacities and V/C RatiosTable 2

Warner Brook Trip Generation

The Institute of Traffic Engineers’ Trip Generation, 9th Edition was used to determine the trips into and out of the proposed Warner Brook development on the property for the weekday morning and afternoon peak hours. Table 3 shows the trip generation calculations for the proposed development.

The proposed development, once it is fully built and occupied in eight to ten years from now, will generate approximately 351 trips during the AM peak hour, 655 trips during the PM peak hour, and 6,548 trips during an entire weekday.

Table 3: Trip Generation for Proposed UsesTable 3.png

Projected Warner Brook peak hour trips can be added to the current average daily peak hour volume, and compare the total to the existing volume capacity of the impacted roads. Purcellville Road, North Hatcher, and Hirst Road would be handling volume at 50% or less of their current capacity. Due to the surplus capacity on these roadways near the property, it is expected that the additional traffic generated by the proposed development would be accommodated on these roadways.

Berlin Turnpike however would be pushing 100% of current capacity. The rezoning process will have to address Berlin Turnpike traffic at Rt. 7 Bypass and Hirst Road. Rezoning approval would depend upon satisfactory solutions, if the County hasn’t already begun improvements by the time Warner Brook rezoning is being considered.

A partial remedy factor will be resulting from the Rt. 7 Bypass and 690 Hillsboro Rd. interchange, planned and funded for the VDOT budget of FY2022. This interchange off Rt. 7 Bypass, and the link to Mayfair Crown Drive would provide an alternative direct access to Warner Brook, alleviating impact on Berlin Turnpike, Hirst Rd, North Hatcher, and Purcellville Road.

Another partial remedy factor would be inevitable plans for the Berlin Turnpike intersection with Hirst Road, which today is already carrying volume in peak afternoon hours that stresses its capacity. As stated above, Loudoun County does have an improvement project for this intersection in the six-year Capital Improvement Program. Funding isn’t available until FY19, so study and design work will not begin until after July 1, 2018.


Development growth cannot proclaim revenue impacts for a Town without addressing or balancing actual costs and expenses that the Town may incur. Warner Brook would definitely bring positive fiscal impact to the Town of Purcellville through one time fees ($10,906,000) and annually recurring fees ($1,448,000). The fiscal impact study by R.C. Lesser & Company (RCLCO), in close cooperation with Town Staff,  was undertaken to achieve real comparisons of the Town’s revenues and expenses from Warner Brook.

Working with Staff, significant specific one time and recurring Town expenses from Warner Brook weren’t readily identified. Consequently RCLCO assumed that new development would be allocated a share of actual general and special fund expenditures. Annual expenses of these funds were expressed as a percentage of annual revenues of the funds. This percentage was then applied to Warner Brook annual revenues as an allocation for possible expenses. Based on this conservative approach, Warner Brook is allocating $485,000 for annual expenses. This projects a net incremental annual recurring fiscal impact to the Town of $962,000 ($1,448,00 revenues less $485,000 allocated expenses).


Warner Brook wouldn’t happen all at once, the project would be relatively slow growth for Purcellville over many years, perhaps ten years to full completion. Even after successive approvals for annexation, rezoning, traffic planning, and final site plan, Warner Brook would not then be developed all at once.  Allowing two years or more for entitlement approvals, subsequent development would likely begin first on the residential component, and on the sportsplex component. These could take over a year to begin delivery and operation or occupancy, perhaps in 2022. The industrial park would take a year after approvals to develop and to begin selling lots, and a few years to fully sell, perhaps by 2025.  The retail center would not likely develop until perhaps four or five years following approvals, seeing occupancy perhaps by 2026. From now until final completion and full build-out delivery, Warner Brook could be an eight to ten year project.

Note that the traffic impacts discussed above also do not all occur at once. Traffic impact would be incurred with successive development phases, and would not be expected to reach peak projected impact  until the end of the eight to ten year development period.