[Ord. 381, 11/14/2005, § 500]
The following minimum subdivision principles, standards, and
requirements will be applied by the Planning Commission, Borough Council,
Borough staff and consultants hired to provide comment in evaluating
applications for preliminary and final plat approval.
[Ord. 381, 11/14/2005, § 501]
1. Land shall be suitable for the intended purpose for which it is to
be subdivided or developed, as demonstrated by the environmental impact
statement and traffic study and other application materials submitted.
2. Land subject to hazards of life, health, and safety such as strip
or surface mined land, quarry land, open ditched and land subject
to flooding or subsidence shall not be subdivided for residential
purposes until all such hazards have been eliminated or unless guarantee
is given that adequate safeguards against such hazards are provided
by the subdivision plat.
[Ord. 381, 11/14/2005, § 502]
1. Proposed streets shall be within recorded rights of way and shall
be properly related to Borough, County and State road and highway
plans that have been prepared and officially adopted and/or filed
as prescribed by law.
2. Where a subdivision plat abuts or contains an existing or proposed
arterial street, the Planning Commission and Borough Council may require
local access streets, reverse frontage lots, or such other treatment
which will provide protection for abutting properties, reduction in
the number of intersections with arterial streets, and separation
of local and through traffic.
3. Cul-de-sac end streets may be permitted when it is clear that through
traffic at such a street end is not essential to the street system
in that district, or to the development of adjacent properties in
the area, or the topography of the ground prohibits the future extension
of the streets.
A. The maximum length of a cul-de-sac street shall be 1,200 lineal feet,
exclusive of the turn-around portion.
B. A turn-around with a cartway diameter of at least 80 feet with a
right-of-way diameter of at least 100 feet shall be required at the
end of all streets.
4. Maximum Allowable Grades; Centerline of Streets.
Type
|
Grade
|
---|
Arterial Streets
|
6%
|
Collector Streets
|
10%
|
Local Streets
|
12%
|
Cul-de-Sac
|
Maximum grade of the turn-around pavement portion of the cul-de-sac
shall be 5%
|
5. Minimum grades on all streets shall not be less than 1%.
6. Vertical curves of proper and adequate length shall be installed
on all street grade changes exceeding 1%, and provide a minimum sight
distance as follows:
Design Speed
(mph)
|
Type
|
Minimum Sight Distance
(feet)
|
---|
60
|
Arterial Streets
|
500
|
40
|
Collector Streets
|
275
|
30
|
Local Streets
|
200
|
7. Alignment.
A. Whenever street lines are deflected in excess of 2°, connection
shall be made by horizontal curves.
B. To ensure adequate sight distance, minimum centerline radii for horizontal
curves shall be as follows:
Design Speed
(mph)
|
Type
|
Minimum Center-Line Radii
(feet)
|
---|
60
|
Arterial Streets
|
1,000
|
40
|
Collector Streets
|
400
|
30
|
Local Streets
|
125
|
8. Widths. Minimum street right-of-way widths and cartway (roadway)
widths shall be as follows:
Type of Street
|
Cartway Width
(feet)
|
Right-of-Way
(feet)
|
---|
Arterial
|
40
|
60
|
Collector
|
26
|
50
|
Local
|
24
|
50
|
9. Street Intersections.
A. Curbs, where required, shall be installed by the developer along
the streets or where deemed necessary for public safety as determined
by Borough Council. The curbs shall be of the type and material as
specified and approved by Borough Council. All curbs at intersections
shall be rounded by a minimum radius of 25 feet for local streets,
30 feet for collector streets, and 40 feet for arterial streets.
B. Where the grade of any street at the approach to an intersection
exceeds 5%, a leveling area shall be provided with a transitional
grade not to exceed 2% for a distance of 25 feet from the nearest
right-of-way line of the intersection.
C. Multiple intersections of more than four roads shall be prohibited.
10. Sight Distances.
A. Along Streets. Proper sight distance must be provided for both horizontal
and vertical curves. Sight distance measurements shall be made along
a simulated driver's line of vision. Minimum sight distances,
thus measured, shall be:
Type
|
Minimum Sight Distance
(feet)
|
---|
Local Street
|
110
|
Collector Street
|
200
|
B. At Intersections. Appropriate sight distances must be maintained
on all approaches. When measured from the intersecting curb line extension
along an approach vehicle travel path, there shall be uninterrupted
sight distance of:
Type
|
Sight Distance
(feet)
|
---|
Local Street
|
70
|
Collector Street
|
90
|
11. Street Offsets. Street offsets of less than 125 feet shall be avoided.
12. Reverse Curves. Reverse curves shall be designed to accommodate anticipated
volumes of traffic at designed speeds.
13. Alleys shall be permitted subject to design approval of the Planning
Commission and Borough Council.
14. Driveways.
A. Driveways shall be located to provide the best visibility possible
within the limits of the property that each driveway serves, and shall
be designed and constructed in accordance with the requirements of
the Borough.
B. Private driveways which function as local streets providing access
to individual residential lots shall be designed in accordance with
this chapter and in compliance with the minimum standards for public
streets.
[Ord. 381, 11/14/2005, § 503]
1. Residential lots shall be subdivided in accordance with the terms of the Zoning Ordinance [Chapter
27] and the provisions contained herein.
2. Subdivision and development of land other than for residential purposes
shall be subject to review by the Planning Commission and Borough
Council insofar as size, depth, width of lots, access to public roads
and parking are concerned.
3. The frontage width of lots fronting a cul-de-sac shall be a minimum
of 50 feet at the right-of-way line.
4. All lot lines shall be set perpendicular or radial to the centerline
of the street whenever possible. All nonradial lines shall be denoted
as such on the plat.
5. Flag lots shall have a reserve strip that has a minimum width of 25 feet for its total length and is for the express purpose of providing vehicular egress, ingress, and utility access to said lot. The area of the flag lot used for access shall not be used in computing the minimum lot area required by the Zoning Ordinance [Chapter
27]. The building setback line shall not be established within any part of the reserve strip. Lot width at the building setback line shall comply with the requirements of the Zoning Ordinance [Chapter
27].
[Ord. 381, 11/14/2005, § 504]
1. Building setback lines shall be in accordance with the terms of the Borough Zoning Ordinance [Chapter
27].
2. Building setback lines shall be recorded on each lot.
[Ord. 381, 11/14/2005, § 505]
1. Block length shall not exceed 1,200 feet nor be less than 500 feet.
2. Blocks shall be at least two lots in depth except for reverse frontage
lots.
[Ord. 381, 11/14/2005, § 506]
1. Easements for sanitary sewer and stormwater sewer shall have a minimum
width of 20 feet and be placed at the side or rear of lots whenever
possible. When Borough Council determines that easements are required
to extend proposed or future utilities the required easements shall
be provided.
2. Anchor easements shall be approximately four feet by 30 feet and
placed on a lot line, at such locations as deemed appropriate by the
utility requiring such easements.
3. Aerial easements shall be a minimum of 15 feet, and located as deemed
appropriate by the utility requiring such easements.
4. Where a subdivision is traversed by a watercourse, there shall be
provided a drainage easement or right-of-way conforming substantially
with the line of such watercourse, and of such width as will be adequate
to preserve the natural flow of water and to provide sufficient width
for maintenance, but not less than 20 feet.
[Ord. 381, 11/14/2005, § 507]
The developer may choose his street names subject to the approval
of the Planning Commission and Borough Council. No street, other than
an extension, may be given the name of an existing street in the 911
or postal service area of which the Borough of Thornburg is a part.
[Ord. 381, 11/14/2005, § 508]
In subdividing land, it shall be done in a manner that will
not have the effect of barring adjacent property owners from access
to any existing or proposed public streets.