HomeMy WebLinkAboutSUB201100029 Review Comments Road Plan and Comps. 2011-10-12Philip Custer
From:
DeNunzio, Joel D., P.E. [ Joel .DeNunzio @VDOT.virginia.gov]
Sent:
Wednesday, October 12, 2011 10:43 AM
To:
Philip Custer
Cc:
Mike Myers
Subject:
SUB - 2011 -00029 Whittington Subdivision
SUB - 2011 -00029 Whittington Subdivision
Phil,
I have reviewed the subject plan and have the following comments:
1. The design exception request appears satisfactory and the approval of the alternate pedestrian facility
will be provided separately.
2. The connectivity index appears to be satisfactory for all phases of the development. The proposed
reduction of the index value is accurately shown on the plans and can be approved.
3. The sight distance for 25 mph is 280 feet. The sight distances are shown as 225 feet.
4. Show sight distance triangles on Route 631 at the proposed entrance.
5. Typical Sections:
a. Pavement widening for the turn, taper and entrance need to be in accordance with the VDOT Standard
WP -2 detail. This standard will also determine the proposed pavement structure on Route 631 for the turn
and taper lane.
b. The front ditch section for a GS -7 standard needs to be a 4:1 slope.
C. The shoulder slope for a GS -7 standard needs to be 5 %.
6. The plan needs to show a detail for the proposed median at the entrance road from station 10 +50 to
12 +25 with adequate drainage. The median needs to indicate whether it is raised or depressed.
7. Show inlet calculations for proposed drainage structures within the roadside ditches.
8. A list of mandatory VDOT inspections should be in the VDOT notes section. These mandatory inspections
will also be listed with the final approval of the plans and the issuance of any permits. These need to include:
Installation of any enclosed drainage system before it is covered
b. Installation of any enclosed utility placements within the right -of -way before being covered
C. Construction of the cuts and fills, including field density tests, before placement of roadbed base
materials
d. A final pavement design, based on actual soil characteristics and certified tests, shall be completed and
approved before the pavement structure is placed
e. Placement of base materials, including stone depths, consistent with the approved pavement design,
prior to placement of the paving course or courses, followed by field density and moisture tests and the
placement of a paving course as soon as possible
Construction of pavement, including depth and density, upon completion as part of the final inspection.
9. CD -2 type cross drains need to be at all vertical sag locations. Some cut to fill transitions still do not show
the construction of a CD -1.
10. Although the proposed traffic count is under 1000 vpd for the roads, you should consider installing UD -4
underdrains along the road or daylight the stone base for the road. The mandatory inspection listed in
comment 8c will review to ensure adequate sub base drainage as required by the VDOT 2007 Road and Bridge
Specifications. If the sub base does not drain properly during this inspection the contractor will be responsible
for modifying the sub base to properly drain.
11. Vertical curve #3 needs to be lengthened to increase the vertical sight distance to 171 feet for the 8.25% adjacent
downgrade. The proposed vertical alignment for future sections of road need to show adequate K and sight distance
values.
12. It appears that the proposed 12% grade can be reduced to 10% or less while maintaining balanced earthwork and
this grade should be lowered for both safety and maintenance reasons. Grades above 10% should only be used in
situations where existing conditions require their use.
13. Road E needs to be designed to 25 mph minimum to avoid unnecessary signage and lowered safety of the road.
The vertical curves can be designed to meet the minimum 25 mph and the horizontal curves already meet the minimum
radius for 25 mph.
14. Show outlet protection for structures ST -1 and ST -4.
15. The loop road will require advisory speed signs on the approach to the 20 mph horizontal curve.
16. Driveways should be 10% or less and designed as a standard PE -1.
17. The proposed access to the storm water basin should be from within the development roads so traffic can utilize
the proposed turn and taper lane. If this cannot be accommodated, the entrance will need to be designed for a
commercial entrance with an adequate grade and sight distance.
18. Because the internal subdivision roads are a rural type typical section and no street trees can be placed in the 4
foot shoulder of the road, the waterline will need to be placed outside of the pavement. It can be placed in the shoulder or
outside of the proposed ditch line.
Please submit a list of revisions to the plans with any future submissions indicating how the above comments have been
addressed.
Thanks
Joel
Joel DeNunzio, P.E.
VDOT Culpeper
Land Development
434 - 589 -5871
ioel .denunzioCa)vdot.viroinia.00v