SD24 - Need For and the Feasibility of New Northern, Southern, and/or Western Access to the Washington Dulles International Airport


Executive Summary:
STUDY PURPOSE AND APPROACH

The purpose of the Washington Dulles International Airport Access Study is to examine the need for and the feasibility of new northern, southern, and/or western access to the Washington Dulles International Airport (Dulles Airport). Through Senate Joint Resolution No. 122 (SJR 122), February 1996, the Virginia Legislature requested that the Virginia Department of Transportation (VDOT), the Metropolitan Washington Airports Authority (MWAA), and the Washington Airports Task Force (WATF) "conduct a study to determine the need for and feasibility of a northern, southern, and western access to Dulles Airport."

To accomplish the intent of SJR 122, a three part approach was used for this access study. An overview of each of the following steps describes sources of information and methods used to complete the study:

• Characterize existing and future passenger and goods travel demand from northerly, westerly and southerly areas to the Dulles Airport,
• Identify alternatives which meet forecast directional access needs, and
• Evaluate the alternatives to demonstrate the ability of each to meet identified needs and feasibility.

NEED FOR ALTERNATIVE ACCESS TO THE DULLES AIRPORT

Increases in Trip Making. The Dulles Airport is expected to grow substantially to accommodate the growing number of air passengers and airport-related employees generated by the growth in population and employment. The increase in passenger volumes at Duties Airport is directly related to expected increases in population. Table 1 characterizes daily trip making by three types of trips from the north, west and south of the airport as well as from the east.

Future trip making to and from the airport from all directions is predicted to increase between 200 and 300 percent. The greatest increase is expected in the "other" trip category coming from or two the north, west and southern quadrants. The predicted growth is more than a 500 percent increase over the 1992 levels. This is a result of the predicted growth in cargo and business uses at the airport as well as the planned siting of the national air and Space Museum (NASM) annex at the intersection of Routes 28 and 50 coupled with the growth in population and employment for the four county areas. While not enough to fully shift the balance in travel from the east to the other three quadrants, the increases in trips from these three lays the basis for a finding of need for consideration of additional access points to the airport.

Increases in Air Cargo. Air cargo growth is expected that an annual growth rate of 6 percent (see Table E-2) will be maintained. In 1993, however, growth totaled 23.7 percent due to the opening of additional cargo space and a dedicated ramp.

Capacity Additions Which Affect Airport Access. Only two additional improvements to roadway capacity near the Dulles Airport are included as part of the regional Constrained Long Range Plan (CLRP). One of these is the widening of the Dulles toll Road (DTR) to three general purpose lanes and a high-occupancy vehicle (HOV) lane in each direction. The improvement is currently under construction. The second improvement is the widening of Route 606, which borders Dulles Airport on the west and north, from two lanes to four lanes between Route 50 and Route 28.

Description of Need. Existing evening peak traffic, as characterized by the LOS D ratings on Route 28 between the Dulles Toll Road and Route 50, on the DTR, and on Route 50 east of Route 28 indicate that, today, there is a need that is directionally based on travel to and from the eastern quadrant. The balance of the road system in the immediate vicinity of the airport, however, indicates a LOS C or better during the evening peak hour.

Future roadway performance is predicted to decline if no additional improvements beyond the two described above are made. Service levels on the DTR and Route 28 south of the DTR and south of Route 50 are expected to be extremely poor (LOS F). The Dulles Greenway is predicted to operate at LOS F between Ashburn Road and Route 28. Route 50 is predicted to experience degraded operations to LOS E by 2020. Both the west-bound and eastbound approaches to the intersection with Route 28 are predicted to operate at LOS E, with traffic volumes on the eastern approach exceeding those on the western approach by 2,000 vehicles. Access to the Dulles Airport under the 2020 Baseline alternative will be delayed as a result of poor levels of service during the evening peak period on Route 28 and the Dulles Greenway and congestion and delay on Route 50.

S.3 DEFINITION OF ALTERNATIVES

Four alternatives (the western access has two options) were developed to test the need for and feasibility of providing access to the Dulles Airport from the north, west or southern areas surrounding the airport. Figure E-1 provides an overview of the airport, its surrounding access roads and the locations of the four proposed build alternatives. Each alternative is summarized generally below.

• The Baseline Alternative (No Action) provides access from the existing Dulles Access Road at its intersection with Route 28. The only planned improvements included in this alternative are the DTR mixed flow and HOV additions and the widening of Route 606 from two lanes to four lanes.

• North Access Alternative includes the existing access from Route 28 and the Dulles airport access Road (DAAR) and a second access point on the north side of the airport from Route 606. This access point was assumed to be an upgrade and completion of the existing north access point that was built, but not opened, when the Greenway was built. The North Access Alternative is essentially already constructed and would require a minor upgrading of the roadway.

• West Access - Option A would introduce a new access point to the Dulles Airport's main terminal from Route 606 on the west side of the airport. The facility is assumed to be a 4-Iane, limited access roadway which will be carried as a tunnel under the existing and planned runways.

• The West Access Alternative - Option B would access the airport's main terminal from a new roadway facility such as the Loudoun County Parkway, the final Tri-County Connector connection currently in the Countywide Transportation Plan for Loudoun County (July 1995). The facility is assumed to be a 4-lane, limited access roadway of approximately four miles in length and would require tunneling under the Dulles Airport runways. No additional widening of Route 606 is included in this alternative.

The South Access Alternative includes the Baseline Alternative access point plus the addition of an exclusive airport in-bound access lane northbound in Route 28 between Route 50 and the airport entrance, running for a distance of approximately 4.5 miles.

FEASIBILITY OF ALTERNATIVES

A review of baseline travel forecast results suggests that airport access demand is increasing while the capacity of the system to handle additional trips is stagnant. Travel estimates indicated that although the greatest volume of trips to and from the airport will be with areas to the east, significant growth in travel from areas to the north, west and south of the airport will result in degraded level of service (LOS) on the Dulles Greenway and on Routes 28, 606 and 50. Feasibility of alternatives was assessed using the following measures:

• Numbers of trips attracted to an alternative,
• Reductions in traffic volume on selected roadways,
• Improvements in Level of Service (LOS) on selected roadway segments, and
• Cost estimates.

Table E-3 provides a comparative matrix of the alternatives performance and cost.

CONCLUSIONS

A new roadway facility and/or completion of the Loudoun County Parkway as part of the Tri-County Connector and/or the 234 Bypass north of Route 66 would provide improved regional access to Dulles Airport from the north, west and south, with its related benefits (refer to the Western Transportation Corridor Study, 1996). However, if a new facility west of the Dulles Airport does not have a direct connection to the airport, the traffic destined to the airport from the west, and south still would be required to continue to use Route 28, the Dulles Greenway and the DAAR.

Once the traveler reaches the airport, the ease by which the traveler enters the airport locally is an important component of the total trip and the continued growth of the Dulles Airport.

The primary evaluation considerations were traffic projections on airport-related roadways and cost estimates. While the West access Alternative - Option B offers the greatest benefits to the overall transportation system, the cost estimate is $248 million in 1996 dollars. This compares to a cost of in 1996 dollars is $26 million for a South Access Alternative which has fewer travel benefits, but still provides for some lessening of congestion.