Annandale Transportation Study - Fairfax County Office of ...

Annandale Transportation Study – Final Report
EXECUTIVE SUMMARY
Fairfax County's Comprehensive Plan for the Annandale Community Business Center (CBC) outlines several
objectives related to future development. The Comprehensive Plan recommends several significant transportation
improvements that are envisioned to have a positive impact on the revitalization efforts in the Annandale CBC. This
Annandale Transportation Study was conducted to analyze transportation system network alternatives, and
to develop associated recommendations for a transportation system plan that handles local and through traffic in an
efficient manner, while facilitating the community redevelopment and revitalization needs.
Since the 1970’s, Fairfax County’s Comprehensive Plan for the Annandale CBC had included a future plan for a
grade-separation of Ravensworth / Annandale and Backlick Roads over Little River Turnpike, and a widening of Little
River Turnpike from four to six lanes through the Annandale CBC. Understanding the potential traffic and land use
impacts of these improvements, the recent Annandale Community Business Center Circulation Study recommended
that a one-way paired street system be added as an option to the Comprehensive Plan as a feasible alternative to the
grade-separation, and that the possible need for a flyover at Annandale and Ravensworth Roads be studied. In 2006,
the County updated the Transportation element of the Comprehensive Plan to allow for some additional potential
roadway improvements pending additional analysis and study. Several subsequent studies have reinforced the need
for a detailed study of a number of transportation network alternatives. This is the objective of the Annandale
Transportation Study.
An Existing Conditions study was performed to summarize and document technical information regarding existing
traffic conditions, roadway infrastructure and previous studies performed for the Annandale CBC and the greater
region. As part of the effort to prepare the Existing Conditions report, a traffic-analysis microsimulation (VISSIM)
model was developed to study existing transportation system operations for the Annandale CBC study area that
served as a basis for evaluating future transportation improvements and land use changes.
Nine network alternatives were considered and, with the exception of Network 0 (No-Build), all of the alternatives
included most if not all of the transportation improvements recommended in the Comprehensive Plan for Fairfax
County. The nine networks included:
An initial analysis was performed for all nine networks that resulted in several significant conclusions. The
Annandale/Ravensworth flyover was shown to provide minimal operational benefits most likely outweighed by other
transportation network and land use impacts. Also, the No-Build Alternative provided inadequate capacity and
operations to support the future land use growth in the greater Annandale area. From the initial operational results,
network Alternatives 2, 5, 6 and 7 were selected to be shortlisted for more detailed study including qualitative and
quantitative analyses.
At a final meeting with Fairfax County Transportation and Department of Planning and Zoning, the results from the
four shortlisted alternatives were reviewed and a determination was made that Alternatives 2 and 5 were the viable
alternatives for implementation. Both Alternatives 2 and 5 have nearly equal merits from a traffic capacity and
circulation aspect and the qualitative issues will be important in selecting the final preferred alternative. Detailed study
of cross section and plan concepts of the alternatives showed that the widening of Little River Turnpike (for either the
whole of Alternative 2 or in portions of Alternative 5) has less of an impact than previously believed because of the
ability to forego the right-of-way requirements normally assumed for the continuous service drive. The removal of
existing portions of the service drives in the corridor substantially reduces right-of-way impacts and allows for a
number of pedestrian, bicycle, transit, land use and visual enhancements to be made in the corridor
A public meeting is currently planned to be held in the spring of 2010 to explain the study process and results, and
network Alternatives 2 and 5 will be presented to the public as the viable candidates for implementation. Solicitation
of comments from the public regarding their view of the pros and cons of each alternative is a desired step in the
process.
Network 0
Network 1
Network 2
Network 4
Network 4a
Network 5
Network 6
Network 7
Network 8
No improvements to the current transportation network
Only the Comprehensive Plan improvements
Comprehensive Plan (Network 1) WITHOUT Annandale Road overpass
Comprehensive Plan EXCEPT 4 lanes on Little River Turnpike
Comprehensive Plan EXCEPT 4 lanes on Little River Turnpike and WITHOUT overpass
Comprehensive Plan WITHOUT overpass and one-way pair on LRT / south loop between John Marr
Drive and Markham (3 WB lanes on LRT, 3 EB lanes on south loop)
Comprehensive Plan W/O overpass and 4 lanes on LRT PLUS one-way pair using both north and south
loops between John Marr and Markham (2 WB lanes on north loop and 2 EB lanes on south loop)
Comprehensive Plan WITHOUT overpass and 3-1 pair on LRT / south loop between John Marr and
Markham (3 WB & 1 EB lanes on LRT, 3 EB & 1 WB lanes on south loop)
Comprehensive Plan WITHOUT overpass, with median U-turns in a wide median along the LRT corridor
between Hummer/Heritage and Evergreen Lane; replaces existing service drive
The networks were evaluated using VISSIM, a microscopic traffic analysis tool that provides the input of originsdestinations
according to the future land uses in the corridor. The model was developed and calibrated to current
conditions, and an evaluation of existing conditions compared favorably to the results from the Annandale CBC
Circulation Study.
April 2010
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