HomeMy WebLinkAboutSUB200500302 Review Comments Waiver, variation or substitution requirement 2008-08-06-1 � IRGINIa�.
County of Albemarle
Department of Community Development
Memorandum
From: Amy Pflaum, Current Development Engineering Review
Date: 7 August 2008
Subject: Redbud Subdivision Phase 2 (SUB200500302) private road request
The request for a private road submitted according to Subdivision Ordinance section
14 -232 has been reviewed. The proposed road is an extension of Redbud Lane, an
existing private road serving 20 lots. The extension of 600' will add 7 lots. The entire
private road would be required to meet the standard for private roads serving 6 lots
or more (14- 412A3), which refers to the VDOT standard. Thus, there would be no
difference between a public road and a private road with regard to earthwork and
environmental impacts. However, the applicant has requested that the Commission
approve VDOT standards for mountainous terrain, as authorized in 14- 412A3a.
Compliance with Subdivision Ordinance section 14- 232A.1;
SECTION 14 -234:
Per Section 14- 234(c), the Commission may authorize one or more private roads to be
constructed in a subdivision if it finds that one or more of the circumstances described
in section 14 -232 exists and that (ordinance language presented in bold italics
followed by staff comment):
1. The private road will be adequate to carry the traffic volume which may be
reasonably expected to be generated by the subdivision.
VDOT standards for residential streets expecting up to 400 vehicle trips per day require
a design speed of 20 miles per hour, a pavement width of 18 feet and a maximum
grade of 10 %. Authorizing the mountainous terrain standard allows the maximum
grade to increase to 16% with up to 400 vehicle trips per day. It also reduces the
required graded shoulder width from 4 feet to 2 feet and the minimum horizontal curve
radius from 120 feet to 95 feet.
With the addition of the 7 new lots, Redbud Lane is expected to carry a projected traffic
volume of 270 average vehicle trips per day. The new section of the road proposed to
serve the additional 7 lots is designed to meet VDOT standards for this traffic volume.
The existing section of the road is designed to be upgraded to meet the VDOT
standards, except for a portion that will remain at its existing grade of 11.6 %. For staff
to approve this design, the waiver must be granted to allow the use of mountainous
terrain standards.
This section of road that will remain at the 11.6% grade is less than 100 feet in length.
The design plan shows adequate sight distance in the area of the steep grade. The
Current Development
Engineering Review
page 2 of 2
design plans for both the existing and new roads contain a typical cross section detail
showing the full 4 foot width graded shoulder. Also, all horizontal curves on the plan
meet the minimum 120 foot radius required by VDOT standards. It is assumed that the
reduction to a 2 foot shoulder and the horizontal curve radius to 95 feet provided by the
mountainous terrain standard will not be sought by the applicant.
The applicant states that the residents along the existing portion of Redbud Lane would
like the road to remain a private street. The residents would also like to see as little
disruption as possible during the upgrade of the street to VDOT standards. The
frontage of several lots abutting Redbud Lane will require regrading during this
upgrade. If this section of the road remains at the existing 11.6 %, a 450 foot section of
the road will not require regrading, causing less disruption to the existing neighborhood.
It should be noted that when this road was proposed as a public street, VDOT was
ready to approve the design with the 11.6% grade.