Reston At The Tipping Point--traffic Congestion & Increased Population Density

Reston at the Tipping Point: Traffic Congestion (Paper No. 2)

Reston at the Tipping Point: Traffic Congestion and Increased Population Density (Paper No. 2)

Terrill D. Maynard Reston, Virginia February 7, 2007

i

Reston at the Tipping Point: Traffic Congestion (Paper No. 2)

Reston at the Tipping Point: Traffic Congestion and Increased Population Density (Paper No. 2)

Preface Reston is at a tipping point, a point of no return in its maturation as one of the nation’s premier planned communities. Within weeks, the Fairfax County Department of Planning will present proposed changes in the county’s Planned Residential Community (PRC) zoning code to the Board of Supervisors that, most importantly, would allow the community’s 64,000 or so population to mushroom to nearly 81,000. This change would be accomplished by simply changing three numbers: the household population factors for single-family detached (houses), single-family attached (townhouses), and multi-family (condominium) dwelling units. By reducing these factors, established in the mid-1970s, to reflect the reality of smaller household sizes in the 21st century, the County would allow developers to build as many as 5,545 single-family detached or 6,161 singlefamily attached or 7,921 multi-family dwelling units in the PRC. The proposed zoning change comes at a time when the County and Reston are anticipating the 2012 arrival of Metrorail at Wiehle Avenue and, several years later, at Reston Parkway as part of the Dulles Corridor Metrorail extension. To better enable development around existing Metrorail stations, the County has amended its comprehensive plan and RA has garnered the approval of landowners in the Reston Center for Industry and Government (RCIG) that borders the toll road and Metrorail route through Reston to allow residential development there. Now County guidelines nearing completion for TransitOriented Development (TOD), that is, high-density mixed-use—residential, office, and retail—communities within a half-mile of Metrorail stations, provide a template for that development. According to the Final Environmental Impact Statement (FEIS) on the Dulles Corridor Metrorail extension, Fairfax County officials anticipate the resulting construction will result in 15,000 new residents and 20,000 jobs in the RCIG, although the specific provisions of the recent comprehensive plan changes would allow greater growth in both residents and jobs. This is the second in a series of papers that examine the implications of the prospective 31,000-plus increase in Reston population and the addition of some 20,000 jobs for Reston’s quality of life1. The core argument of this series is that the Fairfax County Board of Supervisors must recognize and appreciate the full reality it would impose on Reston and the County before it decides to change only one element of that reality—household population factors. 1

The first paper examined the impact of these changes on violent crime in Reston, a vital quality of life issue.

i

Reston at the Tipping Point: Traffic Congestion (Paper No. 2)

Table of Contents

Executive Summary

1

Introduction

7

Baseline: Reston Dulles Corridor Traffic, 2007

8

Reston East—The Wiehle Avenue Area

9

Reston West—The Reston Parkway Area

12

The Reston Area Dulles Corridor Access

15

Planned Reston Roadway Improvements

18

Conclusion

20

Appendices A. Analytical Approach

24

B. Population, Dwelling, and Employment Forecast

27

C. Reston Dulles Corridor Area Traffic Flows, 2007-2022

31

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Reston at the Tipping Point: Traffic Congestion (Paper No. 2) Executive Summary

This paper reports the results of an analysis of Reston traffic growth in the Dulles Corridor area, specifically at the Wiehle Avenue and Reston Parkway between Sunset Hills and Sunrise Valley drives, in the peak traffic “rush hour,” 8AM-9AM. It integrates data from detailed traffic count reports prepared by the Virginia Department of Transportation along the Dulles Corridor, Metropolitan Washington Council of Governments (MWCOG) long-term population and employment projections, transportation effects analysis from the Dulles Metrorail Final Environmental Impact Study (FEIS), and the results of other studies of commuter behavior. Using an input-output model approach, this study projects the likely Reston traffic flows around the Dulles Corridor in 2007, 2012, and 2022 if current plans and proposed zoning changes are implemented. It looks at both the aggravating effects of more population and jobs as well as the mitigating effects of planned roadway improvements. It attempts to use balanced assumptions about population and job growth as well as commuter behavior, eschewing either worst or best case scenarios. The results suggest major traffic increases, including increases with significant safety considerations, in the near term and a doubling of traffic over fifteen years. These rates of traffic increase in Reston run from five to eight times more than the projected growth rate in northern Virginia as a whole. Figure ES1:

Reston Dulles Corridor & Northern Virginia Traffic Growth, 2007-2022 90% Reston Dulles Corridor Area 80%

77.4%

Northern Virginia

70%

63.8%

60% 50% 41.1% 40% 30% 15.4%

20% 10.0% 10%

4.9%

0% 2012

2017

1

2022

Reston at the Tipping Point: Traffic Congestion (Paper No. 2) Most of the early growth will be in Reston East around Wiehle Avenue while later growth will be in Reston West around Reston Parkway. The key driver in the early growth will be the construction of an urban village and a Metrorail station at the Wiehle Avenue overpass. Despite the planned concurrent construction of an extension of Soapstone Avenue over the Dulles Toll Road to Isaac Newton Square, traffic on Wiehle Avenue alone will likely rise by 33% in the next five years. (See Figure ES2A below.) Reston West will see the addition of multi-family dwellings in Reston Town Center over the course of the next fifteen years as well as the development of an urban village around the new Reston Parkway Metrorail station by 2017. (See Figure ES2B below.) Even including the unplanned construction of a second overpass extending Town Center Parkway across the toll road, traffic will escalate by 33% on Reston Parkway in the next decade. The final few years of this forecast sees a continuing increase in traffic consistent with the pace of employment and residential growth. Traffic in Reston East will grow by 80% over the next fifteen years while traffic in Reston West will grow by 76% over the same timeframe.

Figure ES2A:

Projected Reston East Morning Rush Hour Traffic Volume, 2007-2022 8,000 Soapstone Overpass

7,000

Wiehle Avenue

Vehicles

6,000

6,681

6,948

6,563 1,351

1,038

1,327

5,525

5,354

5,597

2012

2017

2022

5,000 4,000

3,850

3,000 2,000

3,850

1,000 0 2007

2

Reston at the Tipping Point: Traffic Congestion (Paper No. 2)

Figure ES2B:

Reston West Peak Morning Rush Hour Traffic, 2007-2022 9,000 Town Center Overpass

8,000

7,848

Reston Parkway

6,976

7,000

1,130

Vehicles

1,053 6,000 5,196 5,000

4,468

4,000 6,718

3,000 2,000

4,468

5,196

5,923

1,000 2007

2012

2017

2022

The bulk of the development-driven traffic produced over the next fifteen years will come from implementation of the urban villages at Wiehle Avenue and Reston Parkway under the County’s Comprehensive Plan. In all, more than 1,500 additional vehicles will be on Reston’s streets during the peak morning rush hour in five years because of this development, mostly in the Wiehle Avenue area. A decade from now, development in these areas will add nearly 2,900 vehicles to area roads and fifteen years from now they will more than 3,900 vehicles to Reston rush-hour traffic. (See Figure ES3 below.) The proposed change in the PRC zoning ordinance that would allow another 16,000 people or so to live in Reston would be a key factor in the increased traffic and have virtually all its impact in RTC and, therefore, on Reston Parkway and later Town Center Parkway overpass traffic. Within five years, traffic in Reston West is likely to increase by 420 vehicles in the morning rush hour period. Five years later, as the RTC fills out with the additional growth possible under the proposed PRC zoning ordinance change, more than 800 additional vehicles would be added to Reston West traffic. In short, passage of the PRC zoning ordinance change would have a significant additional adverse impact on traffic congestion the Reston West area.

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Reston at the Tipping Point: Traffic Congestion (Paper No. 2)

Figure ES3: Added Development-Driven Morning Peak Rush Hour Traffic in Reston, 2012-2022 2012

2017

2022

861 265 1,126

1,119 978 2,097

1,283 1,787 3,070

PRC Zoning Ordinance Amendment Development Reston West 420

849

828

861 685

1,119 1,828

1,283 2,615

1,546

2,946

3,898

RCIG Comprehensive Plan Development Reston East Reston West

Total Added Direct Development Traffic Effect Reston East Reston West Grand Total

Against this projected traffic growth backdrop, current planning to improve roadways to accommodate the projected traffic growth is limited, and none of it includes consideration of the prospective population increase from the proposed change in the PRC zoning ordinance. The two major planned improvements are the construction of a 2,300-space parking ramp at the Wiehle Metrorail station and the extension of Soapstone Avenue over the Dulles Toll Road to Isaac Newton Square to divert north-south Wiehle traffic. As part of the Metrorail station construction, bus drop-off ramps will be built on the eastbound toll road exit ramp at Wiehle Avenue and some additional turn lanes will be built on Wiehle and other streets near the station to accommodate the increased traffic. There are no plans at present to improve Reston Parkway other than the construction of a right-turn lane from the Parkway southbound to Sunrise Valley Drive. New transit-oriented development (TOD) guidelines, now being considered by the County Board of Supervisors suggest that future road improvements near Metrorail stations should be limited to maintain current levels of service, a policy that—if passed—could limit qualitative improvements in traffic flows on Reston Parkway and Wiehle Avenue. On balance, this assessment suggests that the impact of all the planned Reston development on Reston traffic for the next fifteen years has not been fully considered or addressed. The FEIS, published in 2004, does not address the impact of the proposed zoning change on Reston’s population—another projected 16,000 people—and associated traffic because the issue was not on the table at the time. Like the FEIS, current MWCOG employment and population projections include only the projected growth in the RCIG. Neither does the current County Comprehensive Transportation Plan consider this impact on local road conditions. Last year’s Transportation Plan update looked only at the proposed RCIG 4

Reston at the Tipping Point: Traffic Congestion (Paper No. 2) development and approved the shifting of the DTR overpass from west of Reston Parkway to west of Wiehle Avenue to accommodate the new Metrorail station. The minutes of November 2006 meeting of Reston Association’s Transportation Committee indicate it has sent a letter to the RA Board endorsing the proposed PRC zoning ordinance change on the same narrow legal grounds offered by the County. Nothing in the minutes suggests that the Committee examined the projected impact of the prospective population and employment growth on Reston area traffic. In contrast, as the Metrorail environmental impact statement was being prepared several years ago, the RA Board sent a letter to the County requesting that the County initiate a comprehensive planning study to assess the traffic and parking impacts of the new Wiehle Avenue Metrorail station and to make recommendations to accommodate these impacts. It is not clear that the County provided the requested study. If it did, the study has not been made available to members of the Reston Association. In any event, the study would not have included the impact of the currently proposed PRC zoning ordinance change. The absence of plans to add lanes on Reston Parkway and Wiehle Avenue suggests that the current roadways will be forced to absorb overall increases in morning rush hour traffic ranging from more than 41% within the next five years to a 77% increase in traffic flows in fifteen years. This includes a 44% increase in Wiehle Avenue traffic—even with the addition of the Soapstone extension—in the next five years. It also includes a 50% increase in Reston Parkway traffic over fifteen years even if the second overpass or underpass is built west of the Parkway. If a second overpass is not constructed, traffic on Reston Parkway will increase by 76% over the next fifteen years. These projected traffic increases come despite the failing level of service grades the 2004 FEIS gave most of the nearby major intersections in Reston. The impact of the growth in Reston’s population and employment on traffic using the DTR, especially that entering or leaving this vital corridor in Reston, has also not been fully examined. Traffic congestion and safety risks appear to be especially high in the eastbound lanes between Reston Parkway and Wiehle Avenue where some 2,500 vehicles are projected to either enter or exit the DTR in a distance of about one mile just five years from now. More broadly, with Reston becoming an even more important regional employment center, total traffic entering and exiting the two Reston streets is projected to grow by 90% in the next five years and more than double over the fifteen-year projection period. It is not clear that the existing ramps are adequate to handle in the increased traffic without causing traffic backups on either the DTR or Reston streets that would aggravate congestion and increase safety risks. The construction of a 2,300-space parking ramp at the Wiehle Avenue station appears to have adequate capacity to handle projected traffic and it will be an important factor in encouraging people to commute via Metrorail rather than their own cars. On the other hand, the absence of a ramp at the Reston Parkway station—only bus and auto drop-off and pick-up areas—appears to present a 5

Reston at the Tipping Point: Traffic Congestion (Paper No. 2) couple of problems. First, traffic into and out of the station may become congested during the morning rush by the number of vehicles dropping off Metrorail passengers. This could be worse in the afternoon if pick-up vehicles are forced to wait for delayed trains. Second, in the absence of parking at the station, prospective Metrorail passengers may park around businesses nearby or in the RTC parking ramps, diverting them from their intended use to serve local shoppers and business clients. Even now, the south side ramp in RTC—the one to which most commuters would be attracted—is filled near capacity throughout most of the business day. While the proposed TOD guidelines and the Comprehensive Plan encourage pedestrian and bicycle traffic in TOD areas, nothing specific in current planning for the development of the Wiehle or Reston Parkway station areas points to plans to create infrastructure to handle non-driving Metrorail passengers. Indeed, the FEIS notes that, while not providing specific plans for pedestrian and bicycling commuters, nothing in its assessment precludes County or other officials from taking steps to build this infrastructure. With both Reston and the W&OD trails nearby, pedestrian and bicycle commuters would appear to have reason to commute to the Reston Metrorail stations. At this time, however, the prospective increases in vehicular traffic in both station areas suggest that pedestrian/bicycling overpasses will be needed across Sunset Hills, Reston Parkway, and Wiehle Avenue as an essential safety measures. In summary, the prospective consequences on Reston Dulles corridor area traffic from changing the current PRC zoning ordinance have not been addressed and yet, when taken in context, they appear to have serious traffic safety and congestion consequences for Restonians whether they commute by car, bicycle, or foot. Before making more commitments to population and employment expansion in Reston, this analysis suggests that Reston Association and the County need to better understand the likely consequences and potential remedies for Reston commuters, highway safety, and roadway development in the interest of keeping Reston and Fairfax County a safe and satisfying place to live, work, and play.

6

Reston at the Tipping Point: Traffic Congestion (Paper No. 2) Introduction Metrorail is likely to be completed to Dulles International Airport within the next decade in two phases. The first of these will see the arrival of Metrorail at Wiehle Avenue in 2012 if construction proceeds as planned. The balance of the rapid transit line is scheduled to be completed in 2015. The promise of Metrorail has led Fairfax County to adjust its development planning for its arrival. The County comprehensive plan has been amended to allow high-density residential, office, and business development along the RCIG corridor, especially near the two planned Metro stops. The amendment allows for residential development of 30-50 dwelling units per acre and the construction of office buildings up to 140 feet in varying mixes of office, residential, and retail use along the entire corridor. The focus of development would be in a transitoriented, mixed-use “urban village” around the Wiehle Avenue and Reston Parkway stations. To accommodate traffic at the Wiehle Avenue station, the County plans to build a 2,300 parking facility there and an overpass extending Soapstone Drive on the south to Isaac Newton Square on the north of the DTR corridor. This addition would “box” the Metro station, parking ramp, and the bulk of the urban village with servicing roadways. The second Reston Metrorail station—near Reston Parkway—is now scheduled to open in 2015 and plans for its development are less robust, but similar in their thrust. Like the Wiehle Avenue area, the comprehensive plan calls for a high-density, transit-oriented, mixed-use urban village to be built around the Metrorail station. Metrorail station plans there specifically exclude the construction of a parking facility, offering only “kiss-&-ride” and bus drop stops to the south and north of the station respectively. At this time, there are no plans to upgrade roadways in the area or to build a second overpass to handle the projected increase in traffic generated by the station or the additional residences in neighboring Reston Town Center. With traffic congestion at or near the top of Reston community’s quality of life issues as well as County and state legislative and funding concerns this year, understanding how these major transportation changes may affect traffic congestion in Reston and the DTR which serves it is important. This paper examines the impact on local traffic congestion at the Dulles Toll Road along Wiehle Avenue and Reston Parkway during the peak weekday travel hour, 8 AM9 AM. Using an input-output model approach (see Appendix A on methodology for details), this study projects likely Reston traffic flows in 2012, 2017, and 2022 based on an estimate for 2007 derived from VDOT traffic count data. It looks at both the aggravating effects of more population and jobs as well as the mitigating effects of planned roadway and parking improvements. It includes one roadway improvement recently dropped from the Fairfax County transportation plan that will likely be picked up again in the future—the extension of Town Center Parkway over (or under) the Dulles Toll Road. By looking at this projected future, it tries to identify the likely impacts on the Reston’s traffic congestion stemming from planned and proposed population density increases. 7

Reston at the Tipping Point: Traffic Congestion (Paper No. 2) The Baseline: Reston Dulles Corridor Traffic, 2007 At present, more than 8,000 vehicles use Reston Parkway (4,468) and Wiehle Avenue (3,850) during the eight o’clock hour each weekday morning. (See Figure 1 below.) A substantial proportion of these vehicles enter the DTR eastbound, 986 vehicles from Reston Parkway and 803 from Wiehle Avenue. At the same time, a large number of vehicles leaves the DTR at these two Reston thoroughfares, 1,350 at Reston Parkway (22 vehicles per minute) and 838 at Wiehle (14 vehicles per minute). The net effect of these transitions on DTR traffic is to increase the traffic flow eastbound by some 1,400 vehicles and decrease the westward flow by some 1,800 vehicles. Reston experiences a net inflow of 423 vehicles during the peak morning rush hour. In fact, traffic entering and leaving the DTR accounts for an important element of traffic on the two key north-south arteries: 64% of all traffic on Reston Parkway and 49% of traffic on Wiehle Avenue. The remaining traffic on these two streets presumably transits the overpass or, at Wiehle, enters the Park & Ride lot west or the business park east of Wiehle north of the overpass. Together, these two sets of traffic flow serves as a baseline for looking at the impact of future population density increases on Reston’s traffic.

Figure 1: Estimated Reston Dulles Corridor Peak Hour (8AM-9AM) Traffic, 2007 Reston Parkway Total: 4,468 Dulles Toll Road

Wiehle Avenue Total: 3,850

268

1,380

112

838

Westbound

6,846

7,958

8,684

Eastbound

7,937 236

8,687 986

7,958 8,687 138

8

9,352 803

Reston at the Tipping Point: Traffic Congestion (Paper No. 2) Reston East—The Wiehle Avenue Area Reston East will be the focus on residential and commercial development tied to the building of the Wiehle Avenue Metrorail station within the next five years. Thereafter, the filling out of employment and housing opportunities in the area will see lesser gains in Reston East traffic. At present, about 3,850 vehicles use Wiehle Avenue between Sunset Hills and Sunrise Valley Drive in the peak morning rush hour. Of these, about half (1,892 vehicles) use Wiehle to enter or exit the Dulles Toll Road (DTR). More than 1,000 vehicles fill the area’s Park & Ride and other parking facilities as commuters transfer to express buses that them to Metrorail at West Falls Church station. In the next five years, the area will see some 4,000 new residents and 3,000 new jobs in the Wiehle Avenue urban village surrounding the Metrorail station. As a result, total traffic in the area will climb by 70% to about 6,563 vehicles. The number of vehicles using Wiehle Avenue alone will grow some 44% to 5,500 vehicles. In addition, more than 1,000 vehicles will use the new Soapstone Avenue overpass. In this explosive traffic growth, nearly 3,800 of the vehicles on Wiehle Avenue will either enter or exit the DTR as commuters depart from homes or arrive at jobs in the area. These include: • More than 100 buses serving the new Metrorail station and nearly 900 drivers exiting the DTR at Wiehle to use Metrorail. • Some 770 vehicles arriving from the DTR with employees to fill some of the 3,000 new jobs in the new Wiehle urban village. • About 150 vehicles for the 3,100 working residents of the urban village leaving Reston via the DTR to jobs elsewhere in the Washington area. The surge in DTR-linked traffic will be led by a ten-fold increase in traffic (to more than 1,300 vehicles) exiting the eastbound DTR to park at the Metrorail station. Traffic growth from 2012 to 2017 and 2022 will largely stabilize, averaging less than one percent per year, as the commercial and residential development in the Wiehle Avenue area fills out. Traffic will reach a plateau in 2017 when the additions to traffic on Wiehle are essentially offset by the decline in Metrorail-related traffic because Wiehle station will no longer be at the end of the line. In the ensuing five years to 2022, the completion of the urban village’s development and other organic growth in Reston jobs and residents will see traffic in Reston East climb to about 7,800 vehicles with the largest percentage increase occurring on the Soapstone overpass. By this time, traffic at Wiehle Avenue on the DTR will have increased some 20% in each direction due to the commercial and residential development in Reston alone. Overall, traffic in Reston East during the peak morning rush hour will more than double in the next fifteen years with 74% coming in the next five years. That traffic increase will be led by a 44% increase in traffic on Wiehle Avenue, 9

Reston at the Tipping Point: Traffic Congestion (Paper No. 2) most of which will be in the first five-year increment, despite the planned construction of the Soapstone overpass. The County also plans to build a 2,300space parking ramp to accommodate the traffic—some of which is described above—that will park and commute via Metrorail. Other local road improvements in the next five years focus primarily on turn lane improvements. By 2022, Reston East traffic will have increased by some 80% from today’s levels.

Figure 2:

Projected Reston East Morning Rush Hour Traffic Volume, 2007-2022 8,000 Soapstone Overpass

7,000

Wiehle Avenue

Vehicles

6,000

6,681

6,948

6,563 1,351

1,038

1,327

5,525

5,354

5,597

2012

2017

2022

5,000 4,000

3,850

3,000 2,000

3,850

1,000 0 2007

10

Reston at the Tipping Point: Traffic Congestion (Paper No. 2)

Figure 3:

Percentage Increase in Reston East Peak Morning Rush Hour Traffic, 2007-2022 100% Soapstone Overpass 90%

Wiehle Avenue 80.5%

80% 74.4%

73.6%

70% 60%

35.1% 30.9%

34.5%

50% 40% 30% 20%

43.5%

39.1%

45.4%

10% 0% 2012

2017

11

2022

Reston at the Tipping Point: Traffic Congestion (Paper No. 2) Reston West—Reston Parkway Area Traffic along Reston Parkway is now somewhat greater than that on Wiehle Avenue. Nearly 4,500 cars use the Parkway between Sunset Hills and Sunrise Valley Drive during the peak morning rush hour. About 64% of those vehicles (2,870) use the Dulles Toll Road, 56% of which are vehicles arriving at places of employment in Reston. There are no commuter Park & Ride facilities in this area, the closest being more than a mile away at South Reston. This area will see a significant population growth in Reston Town Center (RTC) in the next five years from currently planned high-density multi-family development as well as some employment growth along the RCIG. In total, about 7,000 people will move into dwellings in RTC, and about 1,700 new jobs will be created in the RCIG near the DTR. Additional incremental new jobs and housing may be created elsewhere in this area, for example, a re-development of Lake Anne, but these are not included in this projection. As a result of this growth, traffic will increase by about 700 vehicles or 16% over the next five years on Reston Parkway during the morning rush hour. Some 48% of that traffic—344 vehicles—will come from increases in traffic exiting the DTR at Reston Parkway and bringing commuters to the new jobs in Reston. The new Restonians in RTC will add about 420 vehicles to Reston Parkway, and 257 of these vehicles will use the DTR to commute to work. By 2017, when Metrorail will have been extended to Dulles International Airport as scheduled in 2015, Reston West will see explosive growth in RCIG employment and population as well as continued strong growth in housing in RTC. The new urban village built around the Reston Parkway Metrorail station will include an estimated 3,000 new residents and 5,700 more jobs than today (4,000 more than 2012). In addition, RTC will add another 8,000 residents, 15,000 more residents than live there today. As a result of the major population and employment increases between 2012 and 2017, morning rush hour traffic on Reston Parkway and the new Town Center Parkway overpass will increase by 56% from today’s estimated levels to nearly 7,000 vehicles. More than 5,900 of those cars will be using Reston Parkway—an increase of 33% over today’s traffic levels. More than 1,000 vehicles will use the new overpass extension from Town Center Parkway. Almost 4,200 vehicles or 80% of the Reston Parkway traffic will be entering or leaving the DTR via Reston Parkway. The last five years of the forecast period will see continued major growth in population and employment and, therefore, in traffic in Reston West as it fills out. Another 1,000 people each will establish new residences in the urban village and RTC, and another 3,000 jobs will be created in the RCIG. All told, about 20,000 people are projected to take up residence and another 6,500 are expected to take new jobs in the Reston West area in the next fifteen years. 12

Reston at the Tipping Point: Traffic Congestion (Paper No. 2) The last five-year period ending in 2022 will see morning rush hour traffic in Reston West rise to more than 7,800 vehicles, a 12% increase over five years and a 76% increase in traffic above present levels. Some 6,700 of those cars will use Reston Parkway while the balance will use the Town Center overpass. Of the vehicles on the Reston Parkway, more than 5,700 or 64% will be entering or leaving the DTR.

Figure 4:

Reston West Peak Morning Rush Hour Traffic, 2007-2022 9,000 Town Center Overpass

8,000

7,848

Reston Parkway

6,976

7,000

1,130

Vehicles

1,053 6,000 5,196 5,000

4,468

4,000 6,718

3,000 2,000

4,468

5,196

5,923

1,000 2007

2012

13

2017

2022

Reston at the Tipping Point: Traffic Congestion (Paper No. 2) Figure 5:

Percentage Increase in Reston West Peak Morning Rush Hour Traffic, 2007-2022 90% Town Center Overpass

80%

75.6%

Reston Parkway

70% 56.2%

60%

25.3%

50% 23.6% 40% 30% 20% 10%

50.3%

16.3% 32.6% 16.3%

0% 2012

2017

14

2022

Reston at the Tipping Point: Traffic Congestion (Paper No. 2) Reston Area Dulles Toll Road Access Reston’s population and employment increases will be among the many forces driving up traffic flows during the morning rush hour on the already busy Dulles Toll Road. At present, about 16,600 vehicles arrive in the Reston area on the DTR during the peak rush hour. Of this volume, about 2,593 vehicles leave the DTR and another 2,170 enter the DTR, leaving Reston with a net influx to Reston of some 423 vehicles on workdays. As a result, about 16,200 vehicles depart the Reston area on the DTR, 58% of them headed east towards Tysons Corner and beyond. DTR Ramp Use—2012 The population and employment growth in Reston in the next five years, especially around Wiehle Avenue, will see rush hour DTR traffic arriving in the Reston area climb by about 11% to more than 18,300 vehicles. The projected 1,700 increase in arriving DTR traffic includes both workers arriving at jobs in Reston and organic gains of about 5% in regional traffic. This traffic growth includes the expected mitigating effects of the Wiehle Avenue Metrorail connection, but does not include the potential—and likely—aggravating growth of DTR traffic caused by rapid population growth in Loudoun County or steep population and employment growth in Tysons Corner. Traffic using the ramps in Reston to enter or leave the DTR will increase by 52% in the next five years, a 38% increase in rate of Reston origin/destination DTR traffic over 2007. This increase will be led by a nearly ten-fold increase to more than 1,300 vehicles leaving the eastbound DTR at Wiehle Avenue to make use of the new Metrorail station. Combined with the eastbound entry of about 1,200 vehicles from the Reston Parkway just a mile or so to the west of Wiehle, the risks of congestion and accidents in this short stretch of the DTR is likely to increase substantially. This 2012 net mix of some 2,500 vehicles entering and exiting the DTR in the peak morning rush hour compares with an estimated 1,124 vehicles that make that maneuver now. The more than two-fold increase in traffic will substantially raise the risk of congestion and accidents in this stretch of the DTR. The situation may also be aggravated by virtue of the fact that traffic exiting to Wiehle will be controlled by a traffic light and transit buses serving the Metrorail station will be entering and exiting that flow as they drop off passengers at bays on the exit ramp. Both of these factors make it increasingly likely that exiting traffic will back up on to the DTR, further aggravating congestion and raising the risk of serious accidents. So far as is known, neither VDOT, Fairfax County, nor the DTR’s prospective owners have plans to ameliorate this increased risk. DTR Ramp Use—2017 By 2017, DTR traffic flows arriving in Reston are projected to increase some 15% to more than 19,000 vehicles. Traffic entering and exiting the DTR in Reston will increase at all ramps except the eastbound Wiehle exit ramp. At this 15

Reston at the Tipping Point: Traffic Congestion (Paper No. 2) ramp, traffic will decline about 25% from projected 2012 levels because the Metrorail station there will no longer be at the end of the line. Nonetheless, coupled with the increase in traffic entering the DTR eastbound at Reston Parkway, there will still be a projected combined entry and exit flow in this short stretch of roadway of more than 2,400 vehicles, still more than double current transition traffic levels in this short stretch of the DTR. In short, the traffic congestion and accident risk in this portion of the DTR will still be high. DTR Ramp Use—2022 Traffic on the DTR arriving at Reston is projected to reach some 21,600 vehicles by 2022, up 30% from current traffic flows. About 62% of that increase will be directly driven by the increased employment and population in Reston. The increase in employment and population will put a major burden on the handling capacity of the existing DTR ramp structure during the peak morning rush hour. This year about 4,800 vehicles are expected to use the Reston Parkway and Wiehle Avenue ramps during the morning rush hour. By 2022, more than 9,100 vehicles are projected to be using the ramps, a 92% increase in projected traffic. (See Figure 6 below.) This increase in ramp traffic will significantly affect congestion in two ways: • Like the specific back-up issues caused by the jump in eastbound traffic exiting on to Wiehle in the next five years, the increase in traffic in the next fifteen years—two-thirds of it within five years—may well cause backups on to the DTR or Reston’s feeder streets that increase congestion and the risk of accidents unless significant improvements are made in ramp structures. • Similarly, the increase in traffic on Reston Parkway and Wiehle Avenue tied to use of the DTR poses challenges not only to the ability of those two streets to handle the traffic, but also to the key streets they serve: Sunrise Valley Drive to the south and Sunset Hills Drive to the north. Most affected by this increase would be Reston Parkway south of the overpass, which is now only two lanes wide in each direction. The growth in these flows and their impact on both local streets and the DTR are captured in the Figure 8 traffic flow table below.

16

Reston at the Tipping Point: Traffic Congestion (Paper No. 2)

Figure 6: Projected Dulles Toll Road (DTR) Traffic Flows in Reston, 2007-2022 2007

2012

2017

2022

DTR Traffic Arriving in Reston Eastbound Westbound Total

7,937 8,684 16,621

8,859 9,459 18,318

9,223 9,823 19,046

10,424 11,221 21,644

DTR Traffic Departing from Reston Eastbound Westbound Total

9,352 6,846 16,197

9,508 7,274 17,062

10,132 7,209 17,665

10,839 8,193 19,032

DTR Entry/Exit Traffic in Reston Traffic Exiting DTR Traffic Entering DTR Total % of Traffic on DTR to/fm Reston

2,593 2,170 4,763 28.7%

4,382 2,846 7,228 39.5%

4,779 3,074 7,854 41.2%

5,881 3,268 9,149 42.3%

423

1,537

1,705

2,612

Net Traffic Flow into Reston

Figure 7: Projected Dulles Toll Road Ramp Traffic in Reston, 2007-2022 10,000 From Reston Pkwy

9,000

9,148

To Reston Pkwy From Wiehle

8,000

To Wiehle

7,853

1,932

7,227

7,000

1,754

Vehicles

1,496 6,000 5,000 4,000 3,000

3,084

4,763 1,960

2,508

1,349

1,320

2,422

2,271

2012

2017

1,254

1,617

1,336

2,000 916 1,000

2,796

976 2007

17

2022

Reston at the Tipping Point: Traffic Congestion (Paper No. 2) Planned Reston Road Improvements A review of the Fairfax County Comprehensive Plan, Comprehensive Transportation Plan, and recent County and regional capital investment plans and budgets indicates that few major improvements are planned for Wiehle Avenue or Reston Parkway to accommodate the projected traffic increases over the next 15 years. The two major initiatives that appear in Fairfax County planning are intended to accommodate the arrival of Metrorail at Wiehle Avenue by 2012: The completion of the 2,300-space parking ramp by 2010 and the construction of the Soapstone overpass extension to Isaac Newton Square. In addition to these major initiatives, The DTR exit ramp and left-turn lanes into the Metrorail station will be expanded as part of the Metrorail construction. Similar other turn lane additions around the Wiehle station are also envisioned on Sunset Hills and other streets near the station. The plans do not include any addition to the three existing through lanes on Wiehle between Sunset Hills and Sunrise Valley Drive. At this time, there are no plans to improve Reston Parkway between Sunset Hills and Sunrise Valley Drive except for the addition of a right-turn lane from the southbound Parkway to Sunrise Valley Drive. Last year, the previously planned Town Center Parkway underpass extension to Edmund Halley Drive on the south side of the DTR was set aside to build the Soapstone overpass. Presumably, this Town Center Parkway extension—whether by overpass or underpass—will be re-instituted as plans for Phase II of the Metrorail Dulles extension are developed in the next few years. There are no plans to expand the through lanes of Reston Parkway, which has three lanes each direction north of the DTR overpass and two-lanes on the overpass and south to Sunrise Valley Drive and beyond. In addition to these specific road improvement plans, Fairfax County is in the final phases of approving Transit-Oriented Development (TOD) guidelines for the areas immediately surrounding current and prospective Metrorail stations. In general, these guidelines call for the development of mixed-use—commercial, residential, and retail—communities, including high-density multi-family development. These goals are consistent with the current Comprehensive Plan for the RCIG. As to traffic in TOD areas, the proposed County TOD guidelines call for TODs to “provide for and accommodate high quality transit, pedestrian, and bicycle infrastructure and services and other measures to limit single occupant vehicle trips.” 2 As for roadways in TOD areas, the guidelines state: “Where applicable, a higher level of delay is acceptable for traffic within TOD areas. A non-degradation policy should be applied to areas immediately adjacent to a TOD area and to arterials serving 2

“Staff Report for Out-of-Turn Plan Amendment ST07-CW-1CP,” Proposed Policy Plan Amendment, ST07-CW-1CP, Fairfax County, January 11, 2007, p. 12. The report submits and recommends for approval the draft TOD guidelines proposed by the County TOD Committee.

18

Reston at the Tipping Point: Traffic Congestion (Paper No. 2) the TOD area. This policy requires that traffic flow in these adjacent areas and on arterials serving the TOD area perform no worse after development of a TOD takes place. Where it is not possible or appropriate to maintain a non-degradation policy, in lieu of additional road capacity, there can be improvements, measures and/or monetary contributions to a fund to enable the application of techniques to reduce vehicle trips by an appropriate amount in and around the TOD area.” On balance, this particular guideline indicates that, if the TOD guidelines are adopted, the would offer little, if any, traffic congestion relief along Reston Parkway and Wiehle Avenue near the Metrorail stations although it does not preclude that possibility.

19

Reston at the Tipping Point: Traffic Congestion (Paper No. 2) Conclusions The bulk of the development-driven traffic produced over the next fifteen years will come from implementation of the urban villages at Wiehle Avenue and Reston Parkway under the County’s Comprehensive Plan. In all, more than 1,500 additional vehicles will be on Reston’s streets during the peak morning rush hour in five years as a result of this development, mostly in the Wiehle Avenue area. A decade from now, development in these areas will add nearly 2,900 vehicles to area roads and fifteen years from now they will more than 3,900 vehicles to Reston rush-hour traffic. (See Figure ES3 below.) The proposed change in the PRC zoning ordinance that would allow another 16,000 people or so to live in Reston would be a key factor in the increased traffic and have virtually all its impact in RTC and, therefore, on Reston Parkway and later Town Center Parkway overpass traffic. Within five years, traffic in Reston West is likely to increase by 420 vehicles in the morning rush hour period. Five years later, as the RTC fills out with the additional growth possible under the proposed PRC zoning ordinance change, more than 800 additional vehicles would be added to Reston West traffic. In short, passage of the PRC zoning ordinance change would have a significant additional adverse impact on traffic congestion the Reston West area. Figure 8: Added Development-Driven Morning Peak Rush Hour Traffic in Reston, 2012-2022 2012

2017

2022

861 265 1,126

1,119 978 2,097

1,283 1,787 3,070

PRC Zoning Ordinance Amendment Development Reston West 420

849

828

861 685

1,119 1,828

1,283 2,615

1,546

2,946

3,898

RCIG Comprehensive Plan Development Reston East Reston West

Total Added Direct Development Traffic Effect Reston East Reston West Grand Total

Against this projected traffic growth backdrop, current planning to improve roadways to accommodate the projected traffic growth is limited, and none of it includes consideration of the prospective population increase from the proposed change in the PRC zoning ordinance. The two major planned improvements are the construction of a 2,300-space parking ramp at the Wiehle Metrorail station and the extension of Soapstone Avenue over the Dulles Toll Road to Isaac Newton Square to divert north-south Wiehle traffic. As part of the 20

Reston at the Tipping Point: Traffic Congestion (Paper No. 2) Metrorail station construction, bus drop-off ramps will be built on the eastbound toll road exit ramp at Wiehle Avenue and some additional turn lanes will be built on Wiehle and other streets near the station to accommodate the increased traffic. There are no plans at present to improve Reston Parkway other than the construction of a right-turn lane from the Parkway southbound to Sunrise Valley Drive. New transit-oriented development (TOD) guidelines, now being considered by the County Board of Supervisors suggest that future road improvements near Metrorail stations should be limited to maintain current levels of service, a policy that—if passed—could limit qualitative improvements in traffic flows on Reston Parkway and Wiehle Avenue. On balance, this assessment suggests that the impact of all the planned Reston development on Reston traffic for the next fifteen years has not been fully considered or addressed. The FEIS, published in 2004, does not address the impact of the proposed zoning change on Reston’s population—another projected 16,000 people—and associated traffic because the issue was not on the table at the time. Like the FEIS, current MWCOG employment and population projections include only the projected growth in the RCIG. Neither does the current County Comprehensive Transportation Plan consider this impact on local road conditions. Last year’s Transportation Plan update looked only at the proposed RCIG development and approved the shifting of the DTR overpass from west of Reston Parkway to west of Wiehle Avenue to accommodate the new Metrorail station. The minutes of November 2006 meeting of Reston Association’s Transportation Committee indicate it has sent a letter to the RA Board endorsing the proposed PRC zoning ordinance change on the same narrow legal grounds offered by the County. Nothing in the minutes suggests that the Committee examined the projected impact of the prospective population and employment growth on Reston area traffic. In contrast, as the Metrorail environmental impact statement was being prepared several years ago, the RA Board sent a letter to the County requesting that the County initiate a comprehensive planning study to assess the traffic and parking impacts of the new Wiehle Avenue Metrorail station and to make recommendations to accommodate these impacts. It is not clear that the County provided the requested study. If it did, the study has not been made available to members of the Reston Association. In any event, the study would not have included the impact of the currently proposed PRC zoning ordinance change. The absence of plans to add lanes on Reston Parkway and Wiehle Avenue suggests that the current roadways will be forced to absorb overall increases in morning rush hour traffic ranging from more than 41% within the next five years to a 77% increase in traffic flows in fifteen years. This includes a 44% increase in Wiehle Avenue traffic—even with the addition of the Soapstone extension—in the next five years. It also includes a 50% increase in Reston Parkway traffic over fifteen years even if the second overpass or underpass is built west of the Parkway. If a second overpass is not constructed, traffic on Reston Parkway will increase by 76% over the next fifteen years. These projected traffic increases 21

Reston at the Tipping Point: Traffic Congestion (Paper No. 2) come despite the failing level of service grades the 2004 FEIS gave most of the nearby major intersections in Reston. The impact of the growth in Reston’s population and employment on traffic using the DTR, especially that entering or leaving this vital corridor in Reston, has also not been fully examined. Traffic congestion and safety risks appear to be especially high in the eastbound lanes between Reston Parkway and Wiehle Avenue where some 2,500 vehicles are projected to either enter or exit the DTR in a distance of about one mile just five years from now. More broadly, with Reston becoming an even more important regional employment center, total traffic entering and exiting the two Reston streets is projected to grow by 90% in the next five years and more than double over the fifteen-year projection period. It is not clear that the existing ramps are adequate to handle in the increased traffic without causing traffic backups on either the DTR or Reston streets that would aggravate congestion and increase safety risks. The construction of a 2,300-space parking ramp at the Wiehle Avenue station appears to have adequate capacity to handle projected traffic and it will be an important factor in encouraging people to commute via Metrorail rather than their own cars. On the other hand, the absence of a ramp at the Reston Parkway station—only bus and auto drop-off and pick-up areas—appears to present a couple of problems. First, traffic into and out of the station may become congested during the morning rush by the number of vehicles dropping off Metrorail passengers. This could be worse in the afternoon if pick-up vehicles are forced to wait for delayed trains. Second, in the absence of parking at the station, prospective Metrorail passengers may park around businesses nearby or in the RTC parking ramps, diverting them from their intended use to serve local shoppers and business clients. Even now, the south side ramp in RTC—the one to which most commuters would be attracted—is filled near capacity throughout most of the business day. While the proposed TOD guidelines and the Comprehensive Plan encourage pedestrian and bicycle traffic in TOD areas, nothing specific in current planning for the development of the Wiehle or Reston Parkway station areas points to plans to create infrastructure to handle non-driving Metrorail passengers. Indeed, the FEIS notes that, while not providing specific plans for pedestrian and bicycling commuters, nothing in its assessment precludes County or other officials from taking steps to build this infrastructure. With both Reston and the W&OD trails nearby, pedestrian and bicycle commuters would appear to have reason to commute to the Reston Metrorail stations. At this time, however, the prospective increases in vehicular traffic in both station areas suggest that pedestrian/bicycling overpasses will be needed across Sunset Hills, Reston Parkway, and Wiehle Avenue as an essential safety measures. In summary, the prospective consequences on Reston Dulles corridor area traffic from changing the current PRC zoning ordinance have not been addressed and yet, when taken in context, they appear to have serious traffic safety and congestion consequences for Restonians whether they commute by car, bicycle, or 22

Reston at the Tipping Point: Traffic Congestion (Paper No. 2) foot. Before making more commitments to population and employment expansion in Reston, this analysis suggests that Reston Association and the County need to better understand the likely consequences and potential remedies for Reston commuters, highway safety, and roadway development in the interest of keeping Reston and Fairfax County a safe and satisfying place to live, work, and play.

23

Reston at the Tipping Point: Traffic Congestion (Paper No. 2) Appendix A

Analytical Approach

The approach taken is this analysis was to build a traffic input-output projection model based on contemporary traffic counts for the Dulles Toll Road and the two main Reston streets that connect with it—Wiehle Avenue and Reston Parkway. Standard Virginia Department of Transportation (VDOT) traffic annual average workday traffic (AAWDT) peak hour (“K-factor”) count data from 2005 and hourly traffic counts conducted at Dulles Toll Road (DTR) toll plazas on May 18, 2004, as part of a rate hike proposal study for VDOT served as the foundation information for this analysis.3 The hourly transaction data for the peak morning DTR traffic period in Reston (8AM-9AM) was adjusted to mid-2005. Both the hourly and daily data were then adjusted by average MWCOG growth rate for the metropolitan area to make an estimate for 2007. The Washington Metropolitan Council of Government (MWCOG) updated transportation plan provides the economic growth data from which the underlying base or “organic” annual growth rate was developed. According to that forecast, population in northern Virginia is expected to grow by 26.3% in the forecast period, or about 0.948% per year. At the same time, northern Virginia employment is expected to grow by 44.6% or 0.968% per year over the forecast period. The annual average growth rate of the two combined is 0.958%. This growth rate was used throughout the study to calculate the “organic” rate of traffic growth, that is, traffic growth absent the specific employment and population growth analyzed in the study.4 In rough terms, this indicates that core traffic growth on the DTR and Reston streets will increase about a percentage point per year over the fifteen-year period of this projection. Somewhat different approaches were taken to analyze the impacts of population growth and employment growth in Reston. In general, the impact of Reston population growth on traffic was examined from the perspective of commuter behavior and the mitigating impacts of other transportation modes (particularly Metrorail) and other travel routes (such as proposed overpasses). These were overlaid on the projected characteristics of this new population. In looking at the commuting habits of the new residents of Reston Town Center (RTC) and the two urban villages at the prospective Metrorail stations in particular: 3

Table 2-6a, “Number of Transactions by Plaza and Hour, May 18, 2004,” Dulles Toll Road Rate Adjustment Review, Wilbur Smith Associates, January 10, 2005, p. 2-10 4 “Transportation in the Washington Region,” Chapter 3, 2003 Update to the Financially Constrained Long-Range Transportation Plan for the National Capital Region, National Capital Region Transportation Planning Board, Metropolitan Washington Council of Governments, October 1, 2004. www.mwcog.org/uploads/pub-documents/9VxdWg20041119144728.pdf, Table 3-1 (Round 6.3 Cooperative Forecasts of Population by Jurisdiction), p. 3-7, and Table 3.3 (Round 6.3 Cooperative Forecasts of Employment by Jurisdiction), p. 3-15.

24

Reston at the Tipping Point: Traffic Congestion (Paper No. 2) •

The proportion of the new population that would be working was based on contemporary Ballston urban village census data reporting some 78% of the residents there—virtually all in multi-family dwellings—are employed. • Among these workers, about 80% go to work at their normal place of work on a given workday. The rest go to other workplaces, travel on business, are sick, or are taking a vacation. • Ten percent of these workers walk or bike to work. This is consistent with experience in Arlington urban villages and higher than the Metro-area average of eight percent (“other” modes). • Some 30-39% of the new urban village residents take Metrorail to work. The lower number reflects the new, one-direction availability of Metrorail at Wiehle in 2012 while the higher number reflects recent experience in the “mature” Rosslyn-Ballston Metrorail corridor as reported by the Arlington Planning Division in a briefing to Fairfax County officials. When Metrorail is not available, 10% commute by bus.5 • Twenty percent of the new Reston residents (at Reston Town Center and the two urban villages) have jobs in Reston that do not require them to use Wiehle or Reston Parkway in the study area. • Half of the new residents in RTC and Reston Parkway urban village who do not work in Reston also do not use Reston Parkway. They drive west to Fairfax County Parkway to travel to jobs north, south, or west of Reston. • Twenty percent of commuters ride in carpools. This is consistent with the MWCOG Transportation Plan update, which indicates 19.4% of commuters carpool. • Some 38% of morning commuters travel during the peak hour. This figure is derived from peak period usage data for Metrorail. When all these adjustments are made, every 1,000 new residents in the areas studied adds between 60-114 vehicles to Wiehle or Reston Parkway in the study area during the peak morning rush hour, depending largely on the scope of Metrorail service. Commuters arriving at work in Reston are driven by different and less complex set of considerations. In general, based on the MWCOG transportation plan, 80 percent of them travel to work by personal vehicle in 2000.6 According to this data, 12% took public transit and the other 8% traveled by “other” means (walk, bike). This includes those areas served by Metrorail and other public transit. In this analysis: • Like their Reston resident counterparts, 80% are assumed to go to work at their normal place of work in Reston. • Some 72-80% are assumed to travel by personal vehicle, depending on the availability of Metrorail in Reston. At the low end of vehicle travel, 5

“30 Years of Smarter Growth: Arlington County’s Experiences with Transit-Oriented Development in the Rosslyn-Ballston Metro Corridor,” Arlington County Department of Planning, Housing, and Development, Planning Division, May 2006, slide 42. 6 Ibid, Figure 3-14 (Commuting in the Washington Region by Transportation Mode), p. 3-27.

25

Reston at the Tipping Point: Traffic Congestion (Paper No. 2) this suggests that about half the Reston-bound Metrorail commuters walk or drive to Metrorail stations near their home, an assumption that is high. • Of these personal vehicles riders, 20% carpool, consistent with Metro Washington averages. • Like their outbound Reston counterparts, 38% of them travel to Reston during the peak morning rush hour. In short, every 1,000 new jobs created in Reston adds between 218-242 cars to Reston streets from commuters living outside Reston. Beyond the specific influence of new residents and jobs are some other factors that drive up Reston traffic over the timeframe of this projection. The most important of these is the construction of the Metrorail station at Wiehle Avenue in 2012. During the period it is the end-of-line station for Metrorail: • Eight percent of the personal vehicle traffic eastbound on the DTR will exit at Wiehle Avenue to park at the station and take Metrorail to points eastward in 2012. When the station is no longer a terminal station, the number drops to three percent.7 • More than 100 feeder buses will exit the DTR at Wiehle Avenue during the rush hour to drop-off passengers for Metrorail. Together, these two special sources of traffic add nearly 1,000 vehicles to rush hour traffic on Wiehle Avenue in 2012. Organic Reston population and job growth at 0.958% per year adds between 630 vehicles in five years to 1,372 vehicles in fifteen years to Reston’s streets. The allocation of traffic, especially traffic entering or leaving Reston via the DTR, was handled as follows: • The proportion of traffic using the DTR access ramps was constant at current percentages except when specific local population and employment effects were considered. It grew organically in the absence of specific local changes. • Half of new job-related traffic bound for Reston was assumed to come from each direction on the DTR. At present, more rush hour traffic comes from the east than the west. The difference has no impact on overall Reston street traffic. Restonians leaving the community via the DTR during the rush hour were assumed to do go east or west in the proportions as they do currently.

7

This estimate is based on a study for the DOT/Federal Transit Authority that indicated that less than six percent (5.88%) take public transit to work when they have a choice in a large public survey conducted in 1994. In this study, because the Wiehle station is at the end of the line and heads in the same general direction as most auto commuters, a higher percentage has been used. Table 4-4 (Number & Percent of Trips by Mode Captivity—Work Trips), Impacts of Accessibility, Connectivity, and Mode Captivity on Transit Choice, Center for Urban Transportation Studies, University of Wisconsin—Milwaukee, April 2004, p. 56.

26

Reston at the Tipping Point: Traffic Congestion (Paper No. 2) Appendix B

Reston Population, Dwelling, and Employment Forecast

Population Growth Understanding how Reston’s population will grow under the currently approved Comprehensive Plan for the RCIG and the proposed change in the PRC zoning ordinance household density factors is essential in addressing potential traffic implications. Clearly, the growth will be focused in the RCIG and Reston Town Center, but when the growth occurs there is also important. By in large, it will be shaped by the growth of multi-family housing in RTC and the timing of the emergence of the mixed-use, transit-oriented urban villages around the two Metrorail stations in Reston. In this report, Reston’s 2007 population is estimated to be 64,000 people. This is modestly lower than the estimate of 64,277 for late 2006 provided by the Fairfax County planning staff based on its proposed household population factors for the County. Because Reston has proportionately more smaller-sized multifamily dwellings than the county as a whole, however, the County’s estimate probably overstates Reston’s population some. The total population growth expected in the RCIG is projected at 15,000 people, the number of people Fairfax County reported in the 2004 Final Environmental Impact Statement (FEIS) for the Dulles Corridor Metrorail extension. It is less than the 20,300 population the Association of Reston Clusters and Homeowners (ARCH) projects as the residential development potential of the RCIG. The RCIG growth will come largely in two increments, first, with the completion of the Wiehle Avenue Metro station in 2012 and, second, the tentatively planned completion of the Reston Parkway station five years later. Given the densities authorized by the Comprehensive Plan in the immediate areas around these two stations and the focus on Transit Oriented Development (TOD), most of the projected RCIG growth will occur within the half-mile radius of these stations. The balance will occur in the other roughly two-mile length of the RCIG outside the TOD area. Virtually all of the population growth under the proposed change in the PRC zoning code would occur in Reston Town Center (RTC). Most of the remaining development would occur in the area immediately around the RTC (e.g.—Jonathan’s Keepe) to take advantage the transportation, shopping, and other amenities they would offer. In a few cases, such as Lake Anne, initiatives to re-develop established neighborhoods may also result in higher population densities. Putting these various density increases together in a baseline case and assuming no other changes in zoning factors that could affect population densities 27

Reston at the Tipping Point: Traffic Congestion (Paper No. 2) in Reston suggests that that Reston’s population would grow 50 percent in the next 15 years. This would include two roughly 20 percent increments in each of the next five-year periods, and round out to a population of about 96,000 by 2022. These results are laid out by the key development areas in Table 1 below.

Figure 9: Projected Reston Population by Key Development Areas Year Reston PRC RTC Other (RA) Reston RCIG Wiehle TOD Reston Pkwy TOD Other Reston Total

2007 64,000

-

64,000

5-Yr % Change Cumulative % Change

2012 71,500 7,000 500

2017 80,000 15,000 1,000

2022 81,000 16,000 1,000

5,000 4,000 1,000

12,000 6,000 3,000 3,000

15,000 6,000 4,000 5,000

76,500

92,000

96,000

19.5% 19.5%

20.3% 43.8%

4.3% 50.0%

Projected New Dwellings Given the densities authorized in the areas where this population growth would occur and the fact that there are virtually no other areas in the Reston PRC to build other types of dwellings, all the projected increase in housing is projected to be in high-density multi-family dwellings. This estimate uses the proposed household population factor for multi-family dwellings (2.1 persons per dwelling unit) to estimate the number of people per household. At the proposed household population factors for multi-family dwellings, this means the addition of more than 15,200 condominiums and apartments in Reston in the next fifteen years, increasing the number of multi-family dwellings in the community by 56%.

28

Reston at the Tipping Point: Traffic Congestion (Paper No. 2)

Figure 10: Projected Reston Dwelling Type Mix, 2007-2022 Year

2007*

2012

2017

2022

Single-family Detached

4,247

4,247

4,247

4,247

Single-family Attached

8,205

8,205

8,205

8,205

Multi-family Dwelling

13,991

19,943

27,324

28,753

Reston Total

26,443

32,395

39,776

41,205

53%

62%

69%

70%

% Multifamily Dwelling

*2007 count from FC PRC Issue Paper, 9/1/2006

Employment Growth A wide variety of employment counts, estimates, and forecasts for Reston are available, some anecdotal, others more systematic. For example, quoting Fairfax County officials, the 2004 FEIS projects overall job growth in the RCIG at about 20,000 new jobs when the Dulles Corridor Metrorail extension is completed to the airport. The most systematic effort to project future Reston employment appears to be that provided by the Metropolitan Washington Council of Governments (MWCOG) in its Round 7.0 regional planning effort. Assessing employment by transportation analysis zones (TAZ) within regional “activity centers,” it provides a 2005 estimate for Reston employment as well as projections for 2025 and 2030. Of value in this effort is the fact that the Reston forecasts are divided between east and west Reston areas, roughly corresponding to the RCIG areas influenced by the building of Metrorail. (See Figure 1 below.) The two areas also include nearby business development areas, including Isaac Newton Square in the east and Reston Town Center in the west. What the forecast does not include is possible growth in employment in Reston’s neighborhood shopping centers, although this number is both comparatively small and unlikely to change substantially over the years.

29

Reston at the Tipping Point: Traffic Congestion (Paper No. 2)

Figure 11: Dulles Corridor Regional Activity Centers

Source: “Regional Activity Centers & Clusters,” MWCOG Presentation to The National Capital Region Transportation Planning Board, November 16, 2005

The pattern of employment growth in Reston over the next fifteen years can be interpolated from the MWCOG estimate for 2005 and 2025. These interpolation results are shown in Table 3 below. The projected results indicate that the bulk of Reston’s employment growth will occur over the next decade— first at Wiehle and then at Reston Parkway—as the two Metrorail stations come online. In the next 15 years in which Metrorail will become integral to Reston, total Reston core business area employment is projected to grow by 18,200 jobs, a 21 percent increase to 88,500 jobs. After the projected Metrorail-linked surges, employment will continue to grow steadily through 2030. Figure 12: Reston Employment Forecast--Core Business Areas Year

2005*

2007

2012

2017

2022

2025*

2030*

Reston West % Change

43,412

44,300 2.0%

46,000 3.8%

50,000 8.7%

53,000 6.0%

54,434 2.7%

55,594 2.1%

Reston East % Change

28,401

29,000 2.1%

32,000 10.3%

34,000 6.3%

35,500 4.4%

36,447 2.7%

37,599 3.2%

Total % Change % Cum. Change

71,813

73,300 2.1%

78,000 6.4% 6.4%

84,000 7.7% 14.6%

88,500 5.4% 20.7%

90,881 2.7% 24.0%

93,193 2.5% 27.1%

*MWCOG Revised Round 7.0 Employment Forecast

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Reston at the Tipping Point: Traffic Congestion (Paper No. 2) Appendix C

Reston Dulles Corridor Area Traffic Flows, 2007-2022

2007 Estimated Reston Dulles Corridor Peak Hour (8AM-9AM) Traffic, 2007 Reston Parkway Total: 4,468 Dulles Toll Road Westbound Eastbound

Wiehle Avenue Total: 3,850

268 6,846

1,380 7,958

112 7,958

838 8,684

7,937 236

8,687 986

8,687 138

9,352 803

2012 Projected 2012 Peak Hour Traffic in Reston with RTC Population Growth, Metrorail, Wiehle Urban Village, & Soapstone Overpass Reston Parkway Total: 5,196 Dulles Toll Road Westbound

327 7,274

Eastbound

8,859 380

1,580 8,527 9,648 1,169

Wiehle Avenue Total: 5,525

-

166 8,527

1,098 9,459

9,648 1,324

9,508 1,184

Total: 1,038 Soapstone Overpass

31

Reston at the Tipping Point: Traffic Congestion (Paper No. 2)

2017 Projected 2017 Peak Hour Traffic in Reston with RTC Population Growth, Two Metrorail Stations, Reston West & Wiehle Urban Villages, and Town Center & Soapstone Overpasses Reston Parkway Total: 5,923 Dulles Toll Road Westbound

380 7,209

1,883 8,713

Eastbound

9,223 625

9,973 1,375

Total: 1,053 Town Center Overpass

Wiehle Avenue Total: 5,354

-

162 8,713 9,973 999

1,272 9,823 10,132 1,158

Total: 1,327 Soapstone Overpass

2022 Projected 2022 Peak Hour Traffic in Reston with RTC Population Growth, Two Metrorail Stations, Reston West & Wiehle Urban Villages, and Town Center & Soapstone Overpasses Reston Parkway Total: 6,718 Dulles Toll Road Westbound Eastbound

Wiehle Avenue Total: 5,597

428 8,193

2,202 9,967

169 9,967

1,422 11,221

10,424 882

11,046 1,504

11,046 1,374

10,839 1,168

Total: 1,130 Town Center Overpass

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Total: 1,351 Soapstone Overpass