This chapter shall be known as the "Road and Street Design and
Construction Standards Ordinance of the Municipality of Murrysville."
The purpose of this chapter, as adopted, and all subsequent
amendments that may be adopted, is to regulate new road construction
or reconstruction in order to protect safety and health and provide
for the general welfare of the Municipality by providing procedures
and standards for the design and construction of roads and streets
and all of the associated appurtenances within the Municipality.
As used in this chapter, the following terms shall have the
meanings indicated:
ADT
Average daily traffic.
AWDT
Daily traffic count average over a one-week period.
AXLE LOAD
The total load transmitted by all wheels in a single- or
tandem-axle configuration extending across the full width of the vehicle.
BASE COURSE (BASE)
A layer or layers of specified material of planned thickness
placed between the subbase and surface course to serve one or more
functions, such as distributing load, providing drainage or minimizing
frost action.
DEVELOPER
Any landowner, agent of such landowner, etc., who makes a
subdivision or land development.
DIRECTOR OF PUBLIC WORKS
The appointive employee responsible for the construction,
operation and maintenance of roads and facilities owned and maintained
by the Municipality.
FLEXIBLE PAVEMENT
A pavement structure which maintains intimate contact with
and distributes loads to the subgrade and depends on aggregate interlock,
particle friction and cohesion for stability; generally refers to
bituminous pavement.
LOCAL DELIVERY
Shall be considered as delivery of goods and services by
a vehicle with more than two axles to a property located on a street
or road with a posted weight limit. A local delivery shall not have
a frequency of more than one trip per week for any one property. Examples
of local deliveries are garbage trucks, moving vans, delivery vehicles,
etc. At no time will construction vehicles be defined as a local delivery.
The Municipal Engineer shall make the determination of what constitutes
a local delivery.
MUNICIPAL ENGINEER
The professional engineer appointed by the Municipality of
Murrysville and responsible for the review of road and street designs.
PARKING LANE
A longitudinal strip of roadway intended primarily for the
parking of vehicles.
PAVEMENT STRUCTURE
The combination of select material, subbase, base course
and surface course placed on a subgrade to support the traffic load
and distribute it to the roadbed. Where the single term "pavement"
is used, it generally indicates the entire pavement structure.
RIGHT-OF-WAY
A general term denoting a public way for purposes of vehicular
travel and installation and maintenance of utilities.
ROADBED MATERIAL
The material in cuts and embankments and in embankment foundations
from the subgrade surface down, extending to such depth as affects
the support of the pavement structure.
SELECT MATERIAL
Suitable native materials, clean and free of debris, usually
obtained from designated roadway cuts or nearby borrow areas, or other
similar material used for a specific purpose, e.g., to protect or
improve weaker sections of subgrade or for use as lower subbase layer.
SOIL SUPPORT
Expresses the ability of the roadbed material or subgrade
soil to support the traffic loads transmitted through a flexible pavement
structure.
STABILIZATION
Modification of soils or aggregates by incorporating materials
that will increase load-bearing capacity, firmness and resistance
to weathering or displacement.
SUBBASE
A layer or layers of specified or selected material of planned
thickness placed between the subgrade and base course to serve one
or more functions, such as distributing load, providing drainage or
minimizing frost action.
SUBGRADE
The uppermost layer of roadbed material prepared and compacted
to support a pavement structure.
SURFACE COURSE OR SURFACING
One or more concrete or bituminous bound layers of a pavement
placed on the base course, designed to accommodate the traffic load.
The top layer, sometimes called "wearing course," is designed to resist
skidding, traffic abrasion and the disintegrating effects of climate.
SURFACE TREATMENT
One or more applications of bituminous material and cover
aggregate or a thin layer of plant mix on an existing pavement to
seal and/or rejuvenate the wearing course.
TRAFFIC EQUIVALENCY FACTOR
A number that expresses the relationship between a given
axle load and another axle load in terms of effect on the serviceability
of a pavement structure. Most often, axle loads are equated in terms
of the equivalent number of repetitions of an eighteen-thousand-pound
(18 kip) single axle.
TRAVEL LANE
A longitudinal strip of roadway intended to accommodate a
single lane of moving vehicles.
Specific design standard elements are provided for the Municipality
of Murrysville. Elements not defined by this chapter shall be designed
in accord with the latest requirements and standards of the Pennsylvania
Department of Transportation.
A. Design criteria.
(1) The design speed will be the principal design criteria and shall
be as follows:
|
Table 1
Speed Limits for Various Roadway Classifications
|
---|
|
Roadway Functional Classification
|
Minimum Design Speed
(mph)
|
Posted Speed
(mph)
|
---|
|
Principal arterial
|
55
|
35 to 55
|
|
Minor arterial
|
50
|
35 to 45
|
|
Collector
|
45
|
25 to 45
|
|
Local
|
25
|
25 to 35
|
|
Local, nonmunicipal
|
25
|
N/A
|
(2) Pavement, right-of-way and shoulder width will be as follows:
|
Table 2
Minimum Right-of-Way and Street Widths
|
---|
|
|
Minimum Widths
(feet)
|
---|
|
Functional Classification
|
Right-of-way
|
Paved Road*
|
Travel Lane
|
Shoulder Width
|
---|
|
Principal arterial
|
60
|
24
|
12
|
10
|
|
Minor arterial
|
60
|
24
|
12
|
8
|
|
Collector
|
60
|
24
|
12
|
6
|
|
Local
|
50
|
26
|
13
|
N/A
|
|
Cul-de-sac
|
50
|
24
|
12
|
N/A
|
|
* NOTE: Does not include curb width. Asphalt wedge curb width
will be 12 inches; concrete curb and gutter width will be two feet.
|
B. Design elements. The roadway geometry will conform to the following:
(1) Horizontal alignment shall be as follows:
|
Table 3
Horizontal Alignment
|
---|
|
|
Horizontal Radius (in feet) for Design Speed (in mph)
|
---|
|
Cross Slope
|
25
|
30
|
35
|
45
|
55
|
|
0.02 foot per foot
|
150
|
250
|
325
|
575
|
925
|
|
* NOTE: Superelevation and curve widening may be required for
speeds above 35 miles per hour.
|
(2) Vertical alignment shall be as follows:
|
Table 4
Vertical Alignment
|
---|
|
Design Speed (mph)
|
25
|
30
|
35
|
45
|
55
|
|
Minimum stopping distance (feet)
|
150
|
200
|
250
|
350
|
475
|
|
Minimum K Value*
|
|
|
|
|
|
|
|
Crest vertical curve
|
15
|
25
|
41
|
93
|
152
|
|
|
Sag vertical curve
|
23
|
33
|
45
|
75
|
103
|
|
Maximum grade
|
14%
|
14%
|
12%
|
10%
|
7%
|
|
Minimum grade
|
2%
|
2%
|
2%
|
1%
|
1%
|
|
* NOTE: "K Value" is the ratio of vertical curve length to algebraic
difference in grades. The minimum length of any vertical curve will
be 50 feet. "K value" criteria is not to be used at intersections.
|
C. Intersections.
(1) Intersection geometries shall be as follows:
(a)
The desirable intersecting angle is 90°, and the minimum
acceptable angle shall be as follows:
[1]
Arterials and collectors: 80°.
(b)
No new intersection shall be within 125 feet of another existing
or proposed intersection unless approved by the Murrysville Council.
(c)
No new driveway shall be within 75 feet of an existing or proposed
intersection. Where lot frontages prohibit this, a reasonable distance
will be used as approved by the Municipal Engineer.
(d)
No intersection shall have more than four intersecting roadways.
(e)
To assure adequate turning radii, the minimum corner radii will
conform to the following table:
|
Table 5
Minimum Corner Radii
|
---|
|
|
Minimum Corner Radii
|
---|
|
Functional Classification
|
Right-of-way
(feet)
|
Pavement
(feet)
|
---|
|
Principal arterial
|
55
|
45
|
|
Minor arterial
|
55
|
45
|
|
Collector
|
45
|
35
|
|
Local:
|
|
|
|
|
Residential
|
35
|
25
|
|
|
Commercial
|
55
|
45
|
|
|
Industrial
|
70
|
55
|
(2) Traffic control devices.
(a)
The following devices will generally be required at intersections.
In the case of private construction of roadways for inclusion in the
municipal system, the cost of engineering, materials and installation
will be borne by the developer.
|
Table 6
Traffic Control Devices
|
---|
|
|
Intersecting Roadway Classification
|
---|
|
Main Roadway Classification
|
Local
|
Collector
|
Minor Arterial
|
Principal Arterial
|
---|
|
Local
|
Yield or stop sign
|
N/A
|
N/A
|
N/A
|
|
Collector
|
Yield or stop sign
|
Stop sign or traffic signal
|
N/A
|
N/A
|
|
Minor arterial
|
Stop sign or traffic signal
|
Stop sign or traffic signal
|
Traffic signal
|
N/A
|
|
Principal arterial
|
Stop sign or traffic signal
|
Stop sign or traffic signal
|
Traffic signal
|
Traffic signal
|
(b)
All traffic signals shall be electrified and meet the Pennsylvania
Department of Transportation requirements.
(c)
A new residential and commercial development shall be required
to submit a signing plan as part of the development plans.
(3) Stopping distances. The minimum stopping sight distances at intersections
will comply with the following table:
|
Table 7
Minimum Stopping Sight Distance
|
---|
|
|
Minimum Sight Distance
(feet)
|
---|
|
|
Grade
|
---|
|
Posted Speed Limit
on Intersecting Street
(mph)
|
+9%
|
+6%
|
+3%
|
0%
|
-3%
|
-6%
|
-9%
|
---|
|
25
|
135
|
140
|
150
|
150
|
160
|
170
|
180
|
|
35
|
225
|
230
|
240
|
250
|
260
|
275
|
295
|
|
45
|
N/A
|
320
|
330
|
350
|
410
|
435
|
N/A
|
|
55
|
N/A
|
425
|
445
|
475
|
575
|
625
|
N/A
|
(4) Intersection standards. New or modified streets or intersections
and access driveways shall be designed for adequate traffic capacity,
defined as follows, unless otherwise approved by the Municipal Engineer.
All references to "level of service (LOS)" shall be as defined by
the Highway Capacity Manual, Special Report 209, as amended or replaced,
published by the Transportation Research Board.
(a)
Traffic capacity LOS shall be based upon a future design year
which coincides with the completion of the development of Pennsylvania
Department of Transportation requirements.
(b)
Unsignalized intersections or driveways which intersect streets
shall be designed for LOS C or better for each new traffic movement.
(c)
Signalized intersections shall be designed for LOS C or better
for each new traffic movement. The LOS of existing traffic movements
shall not be degraded.
(d)
Streets shall be designed for a minimum LOS C.
(e)
Sight distance at driveways and new intersections shall meet
standards specified by Pennsylvania Department of Transportation regulations.
D. Drainage design and related procedures.
(1) General criteria. A stormwater management plan shall be prepared
in accordance with the Murrysville Stormwater Management Ordinance. Underground storage tanks are not permitted in any road
right-of-way (public or private).
(2) Design methods (street drainage design).
(a)
Stormwater drainage systems will be designed using the most-current
method described in the Pennsylvania Department of Transportation
Drainage Manual.
(b)
All street drainage structures will be designed to accommodate
the stormwater runoff generated by the ten-year storm return frequency.
(c)
A report must be submitted that shows the capacity of all pipes
and inlets. A plan showing the pipe profiles and other details of
the system must be provided.
(3) Design details.
(a)
All drainage ditches or storm sewers must be designed in accordance
with the Murrysville Stormwater Management Ordinance.
(b)
All inlets shall have a Type M top with a cast-iron frame and
bicycle-safe grate approved by the Municipal Engineer. The inlet shall
comply with most-current Department of Transportation Standards of
Construction. Steps at twelve-inch centers will be installed in all
inlets five feet and deeper. Inlet tops will be constructed to match
the grade and cross slope of the roadway.
(c)
Pipe for storm sewers shall have a minimum of diameter of 15
inches. Pipes shall either be reinforced-concrete pipe or smooth-walled
plastic pipe (as manufactured by ADS or an equivalent). Metal pipes
are not permitted.
(d)
All natural springs becoming apparent during construction will
be piped to the nearest wetland, stream or storm sewer.
(e)
Any drainage structure not described in the Pennsylvania Department
of Transportation Standards of Construction will be detailed on the
plan submitted to the Municipal Engineer. This shall include but not
be limited to culverts, wingwalls and headwalls, bridges and channels.
(f)
All storm drainage will be designed with a minimum slope of
1%.
(g)
All ditches will be lined with the appropriate material as dictated
by the design velocities.
(h)
The maximum spacing of inlets will be 400 feet between inlets
or downstream from the high point of the street.
(i)
Bituminous curbs will be a wedge-type curb 12 inches wide and
have a depth of five inches.
(j)
All utility trenches within three feet of the existing or proposed
pavement will be backfilled with coarse aggregate (limestone only).
(k)
All manholes will comply with Pennsylvania Department of Transportation
Standards of Construction and will be constructed of either precast
or cast-in-place concrete.
(l)
Storm sewers on slopes of 20% or greater will be anchored with
concrete anchors, spaced as follows:
[1]
Not over 36 feet center to center on grades of 20% to 35%.
[2]
Not over 24 feet center to center on grades of 35% to 50%.
[3]
Not over 16 feet center to center on grades over 50%.
(4) Pavement base drain. Longitudinal pavement base drain, a minimum
of four inches in diameter, will be installed on both sides of the
roadway. All drains will be installed per the most-current Pennsylvania
Department of Transportation Standards for Construction. Pavement
base drain installation will typically extend from inlet to inlet
or manhole, with both ends of any given run extending into the inlet
or manhole to allow for future maintenance.
(5) Roof, yard and driveway drains. No drainage from dwellings or other
buildings nor downspouts for roof drainage will be piped onto the
road surface. No drainage system will be connected to the pavement
base drains.
E. Pavement design.
(1) Purpose. The purpose of these pavement design standards is to provide
an adequate pavement structure for the soil support available and
the traffic anticipated. The standards are also intended to provide
this structure as economically as possible.
(2) Minimum design. The pavement structure will be designed to provide
the following minimum thickness, unless otherwise stated in the following
tables:
(a)
Subbase: six inches of 2A limestone with a Class 4 geotextile
material.
(b)
Base course: three inches of Superpave Asphalt Mixture Design,
HMA Binder Course 25 mm, PG 64-22.
(c)
Wearing course: three inches of Superpave Asphalt Mixture Design,
HMA Wearing Course 9.5 mm, PG 64-22, SRL-H (includes final 1 1/2
inches).
(3) Materials. All materials will conform to the most-current Pennsylvania
Department of Transportation Publication 408 standards. The developer
must submit an approved mix design prior to construction of the roadway.
(a)
Wearing surface. The wearing surface will be constructed with
Superpave Asphalt Mixture Design, HMA Wearing Course 9.5 mm, PG 64-22,
SRL-H.
(b)
Base course. The base course will be constructed with Superpave
Asphalt Mixture Design, HMA Binder Course 25 mm, PG 64-22.
(c)
Subbase. The subbase will be constructed with Pennsylvania Department
of Transportation approved 2A or 3A material (limestone only; slag
is not permitted).
(d)
Geotextile fabric. Pennsylvania Department of Transportation
Class 4 geotextile will be used on all subgrade. Other geotextile
fabrics may be used when conditions warrant and with the Municipal
Engineer's approval.
(4) Design method. The determination of the soil support and traffic
intensity categories will be made by a registered professional engineer
with experience in pavement design. The categories will be made using
data and methods approved by the Municipal Engineer.
(a)
Soil support. The pavement subgrade will conform to the requirements stated in this chapter. All subgrade will be well-compacted and nonplastic in nature. Through the use of proof-rolling (§
97-6D), the Municipality will determine the subgrade quality. Only quality subgrade will be accepted.
(b)
Traffic intensity design index. A design index (DI) number shall
be determined from Table 8 for maximum traffic intensity anticipated
to occur on the street during the first fifteen-year life cycle of
the street.
|
Table 8
Traffic Intensity Categories
|
---|
|
DI-1
|
Light traffic (passenger cars with truck traffic limited to
local deliveries; includes most residential subdivision streets)
|
|
DI-2
|
Medium to light traffic (similar to DI-1 but with greater frequency
of truck traffic; includes residential streets exceeding 1,000 vehicles
per day)
|
|
DI-3
|
Medium traffic (similar to Dl-2 but including some light commercial
traffic)
|
|
DI-4
|
Medium to heavy traffic (up to 2,000 vehicles per day, mixed
types, less than 5% maximum legal axle loads traveling the same wheel
path patterns)
|
|
DI-5
|
Heavy traffic (up to 2,000 vehicles per day, up to 25% DI-5
commercial, up to 10% maximum legal axle loads)
|
|
DI-6
|
Very heavy traffic (over 2,000 vehicles per day, high frequency
of legal axle loads)
|
(c)
Design thickness for normal environment. Based upon soil support
and traffic intensity categories, the design thickness for the pavement
structure shall be determined from Table 9.
|
Table 9
Flexible Pavement Design
|
---|
|
Pavement Design Thickness1
(inches)
|
---|
|
DI-1
|
DI-2
|
DI-3
|
DI-4
|
DI-5
|
DI-6
|
---|
|
62
|
6.5
|
7
|
8
|
93
|
103
|
|
NOTES:
|
---|
|
1
|
Excluding the subbase. Subbase for DI-1 and DI-2 will be a minimum
of six-inches. The subbase for DI-3 to DI-6 must be submitted to the
Municipal Engineer for approval.
|
|
2
|
See minimum design standards.
|
|
3
|
Alternative reinforced concrete pavement may be submitted for
approval.
|
F. Roadway appurtenances.
(1) Guiderail. The use of guiderails will be avoided except in the case
where site conditions warrant such safety devices. Earthwork and landscaping
will be done in such a manner as to eliminate any unsafe conditions
or hazards near the roadway. Guiderail construction will follow the
most-current sections of the Pennsylvania Department of Transportation
Road Construction Standards and Publication 408. All guiderails will
have proper end treatments. When guiderails are required in a residential
subdivision, consideration will be given to the use of alternate designs.
(2) Pedestrian facilities.
(a)
Sidewalks. Sidewalks may be constructed in accordance with the
Municipality's Subdivision Ordinance. When sidewalks are constructed, they will have a minimum
width of five feet and a minimum thickness of four inches of reinforced
concrete and four inches of stone base. At locations where sidewalks
cross driveways, the minimum concrete thickness shall be increased
to six inches. Alternate designs may be submitted to the Municipal
Engineer for approval.
(b)
Curb-cut ramps. Curb-cut ramps will be required at all intersections
where sidewalks are present and at other locations deemed necessary
by the Municipal Engineer. Curb-cut ramps will be designed as a sidewalk
section in accordance with the most-current requirements of the Pennsylvania
Department of Transportation.
(c)
Pedestrian signals. Pedestrian signals will be required where
the safety of pedestrians warrants such devices. When pedestrian signals
are required, they will be designed and constructed in accordance
with the most-current requirements of the Pennsylvania Department
of Transportation.
(3) Utilities. In accordance with the Municipality's Subdivision
Ordinance, all utilities will be located in the public right-of-way
but outside the pavement section, or within a utility easement, wherever
possible. All utilities will be located a minimum of 3.5 feet behind
the back of the curb. When utilities must cross the pavement, they
will do so at an angle perpendicular to the longitudinal direction
of the pavement. If future utilities are forecast to cross the pavement
section, the developer will install metal or plastic conduit pipe
to accommodate such utilities. All utilities and/or conduits will
be installed prior to the placement of any pavement. For the construction
of utilities within existing municipal rights-of-way, all provisions
of the Pennsylvania Department of Transportation Publication 408 and
Pennsylvania Code, Title 67, Chapter 459, Occupancy of Highways by
Utilities, shall apply for work within the right-of-way. Manholes,
valve boxes, curb stops and other such accessways shall be kept out
of the sidewalk areas.
(4) Driveways. All private driveways will be so located as to conform
to the stopping sight distance requirements listed in this chapter.
The maximum grade on a driveway will be 15%. All other driveway design
criteria will be as defined in Chapter 441 of Title 67 of the Pennsylvania
Code, Access to and occupancy of highways by driveways and local roads.
(5) Curbs and shoulders. The standard curb for local roads will be a
bituminous wedge curb 12 inches wide and five inches in height. The
wedge curb will be constructed at the same time and of the same material
as the roadway. Concrete curbs may be constructed where conditions
warrant their use or when directed by the Engineer. Concrete curbs
and gutters will be constructed in accordance with Pennsylvania Department
of Transportation RC-64 Standards. When it is necessary to construct
roadway shoulders, either a Type 1 or Type 3 shoulder may be used,
as directed by the Engineer. Shoulder construction will be in accordance
with the most-current Pennsylvania Department of Transportation Road
Construction Standards.
(6) Parking lots. The design of parking lots will be as described in
the Municipality's Zoning Ordinance. In addition to those requirements, in order to assure
proper drainage, the minimum grade will be 1%, and the maximum grade
will be 7%.
(7) Temporary turnarounds. Temporary turnarounds will not be permitted.
If the proposed development is to be constructed in phases, the streets
shall be so designed as to have the phase line at an intersection.
G. Earthwork. All earthwork will be in accordance with the Municipality's
Land Operations Ordinance. In addition, all earthwork will be performed under the
supervision of a qualified geotechnical engineer when recommended
by the Municipal Engineer.
H. Erosion and sedimentation control. All new roads will be constructed
in such a manner as to minimize erosion and prevent the release of
sediments into any body of water. An approved erosion and sedimentation
control plan must be on file with the Municipality before any road
work will be permitted to commence. Also, all required erosion and
sedimentation control devices must be installed before earthmoving
begins. The erosion and sedimentation control plan and all necessary
devices will be in conformance with the Pennsylvania Department of
Environmental Resources Soil Erosion and Sedimentation Control Manual
and the Westmoreland Conservation District.