Notes from the Planning Commission work session on November 7th and subsequent conversations with staff:

The major driver for the large projected increases on Purcell Road in the future is the proposed "Tri-County Parkway" that would follow the path of the current Rt. 234 in our area and ultimately serve the Dulles Airport area using new sections of road. The projected route of the Tri County Parkway would follow Rt. 234 from Rt.95 on the east/south and end on the backside of Dulles Airport in the west/north. According to the county transportation model, this road will result in large increases in traffic volumes in the Rt. 234/Hoadly Road/Purcell Road/PW Pkwy area (traffic increases on Purcell are projected to be from around 8,000 trips per day to about 28,000, or over 300%). Even if Purcell is expanded to 4-lane status and connected to the Parkway, a good portion of the road falls to below acceptable status in 25-30 years. If Purcell is left as is, the whole road falls to below acceptable status, so the level of congestion is really just a matter of degree- part of it fails either way (4 lane or not) 30 years into the future if the Tri-County Parkway is built. 


Note: see blog section for opinion piece on this subject.