Union Township City Zoning Code
§ 30-22.8
New Residential Streets.
[Ord. No. 85-9, § 2207; Ord. No. 86-4, § 10; Ord. No. 92-9, § 1]
a.
Purpose. The purpose of these provisions is to establish appropriate standards for the design of streets in residential subdivisions that will (1) promote the safety and convenience of vehicular traffic, (2) protect the safety of neighborhood residents, (3) minimize the long term costs for maintenance and repair of streets, (4) minimize crime in residential areas, (5) protect the residential qualities of neighborhoods by limiting traffic volume, traffic speed, noise, and fumes, (6) encourage efficient use of land, (7) minimize the cost of street construction, and (8) minimize the construction of impervious surfaces.
b.
Street Hierarchy. The intent of this subsection is to create an integrated residential street system by creating varying street standards within which the developer may design a residential subdivision or land development. The street hierarchy is related to average daily traffic (ADT) levels, lot frontage, and the need for on-street parking. The following hierarchy is hereby established.
c.
Classification. New residential streets will be classified according to the expected ADT level of the streets. If subdivision lots are large enough for further subdivisions, the Township Planning Board may require that the street be constructed to the standards of a higher classification, unless deed restricted against further development.
d.
Stub Streets. Stub streets will be permitted only within subsections of phased development as a temporary condition in which the stub street is a portion of the overall street system.
e.
Design Options.
1.
All new residential streets shall be designed to meet the standards in the Table of Street Design Options and the following requirements for individual street types.
2.
No new residential street may tie into an existing residential street if the expected ADT from the new development will exceed the allowable ADT level for that street classification.
f.
Trip Generation Rates. The following chart shall be used to determine the ADT levels of proposed residential developments and streets.
Housing Type | Average Weekday Trip Generation Rates |
|---|---|
Single Family Detached | 10.0 trips/du |
Duplex (twin), multiplex, townhouse | 8.1 trips/du |
Apartment | 5.4 trips/du |
Mobile Home | 5.4 trips/du |
Retirement Village | 3.3 trips/du |
g.
Spillover Parking.
1.
Spillover parking spaces are parking spaces that are needed to accommodate the vehicles of infrequent visitors such as guests or repairmen. These spaces are required in addition to the number needed to accommodate the residents. Spillover parking may be provided on the individual lots, in separate parking areas, or in common parking areas.
2.
When off-street spillover parking is required in the Table of Design Options,[1] it shall be provided at the following rates in addition to the minimum requirements of the Township zoning ordinance.
Housing Type | Spillover Parking Spaces Required per Dwelling Unit |
|---|---|
Single family detached | 1.0 |
Attached units | 1.0 |
Apartments | 0.5 |
[1]
Editor's Note: The Table of Design Options can be found at the end of this section.
3.
When spillover parking is provided on the individual lots the following criteria must be met:
4.
When spillover parking is provided within the cartway, minimum cartway shall be 23 feet.
h.
Residential Access Streets.
1.
Residential Access Streets. This is the lowest order street in the hierarchy. It is intended to carry the least amount of traffic at the lowest speed. It will provide the safest and most desirable environment for a residential neighborhood. Developments should be designed so that as many houses as possible front on this type of street.
2.
Service Restrictions. Each residential access street shall be designed as that no section of the street conveys a traffic volume greater than 200 ADT. Each half of a loop street may be regarded as a single local access street, and the total traffic volume conveyed on a loop street shall not exceed 400 ADT.
3.
Street Access. A residential access street may intersect or take access from any existing street type. Both ends of a loop street, however, must intersect the same collecting street and be laid out to discourage the passage of through traffic on it.
4.
Street Width and Curbing. See the Table of Street Design Options at the end of this section.
5.
Shoulders. When curbing is not required, two foot wide stabilized turf shoulders shall be provided on both sides of the cartway.
6.
Length of Cul-de-sac. No cul-de-sac shall exceed a length of 1,000 feet unless specifically authorized by the Planning Board. Cul-de-sac length shall be measured along the centerline of the intersecting through street to the center point of the turnaround.
7.
Cul-de-sac Turnaround. A paved area with an outside turning radius of 40 feet shall be provided at the terminus of every permanent cul-de-sac. If the radius is more than 40 feet, a center island should be provided. Ring-shaped culs-de-sac shall provide a continuous fifteen-foot wide paved cartway. Other alternative designs may be approved, provided that they meet these minimum radius and cartway width requirements. Centerline grade in turnaround shall not exceed 5%.
8.
Engineering Criteria. All features of the geometric design of residential access streets that are not specified below shall be designed for a design speed of 25 miles per hour.
i.
Residential Subcollector.
1.
Residential Subcollector Streets. This is the middle order street in the hierarchy. It will carry more traffic than the residential access street. It should provide an acceptable environment for a residential neighborhood.
2.
Service Restrictions.
(a)
No subcollector shall be designed so that any section of it conveys a traffic volume greater than 500 ADT. (Each half of a loop subcollector street may be regarded as a single subcollector street and the total traffic volume conveyed on a loop street shall not exceed 1,000 ADT.)
(b)
Subcollector streets shall be designed to exclude all external through traffic which has neither origin nor destination on the sub-collector or its tributary residential access streets.
3.
Street Access. Every subcollector must be provided with at least two access intersections to a street of higher classification in the streets hierarchy, namely existing or proposed collector roads or arterial highways. In no case shall a subcollector end in a cul-de-sac.
4.
Street Width and Curbing. Refer to the Table of Street Design Options at the end of this section.
5.
Shoulders. When curbing is not required, two-foot wide stabilized turf shoulders shall be provided on both sides of the cartway.
6.
Moving Lanes. All subcollector streets shall be provided with two continuous moving lanes within which parking is prohibited.
7.
Engineering Criteria. All features of the geometric design of subcollector streets that are not specified below shall be designed for a design speed of 30 miles per hour.
j.
Residential Collector.
1.
Residential Collector Street. This is the highest order street that could be classified as residential. It will carry the largest volume of traffic at higher speeds. In large residential developments, this class of street may be necessary to carry traffic from one neighborhood to another or from the neighborhood to streets connecting to other areas in the community. This level of street is unsuitable for providing direct access to homes, and provisions of such access to homes should be avoided.
2.
Service Restrictions.
(a)
Provisions of a residential collector street or road system is mandated wherever any proposed development is of sufficient magnitude to render it impossible to meet maximum anticipated service volume (ADT) standards established for local access and subcollector streets. Generally, a nonfrontage collector may be necessary whenever a development exceeds 150 dwelling units, or when it carries external traffic in addition to traffic generated by the development.
(b)
Residential collectors shall be laid out to discourage excessive external through traffic, except where linkage between bordering roads may be determined to be desirable as indicated in the Township master plan or by the Township Planning Board during plan review. Upon recommendation of the Township Engineer, the Township Planning Board may impose additional standards on the design of the roadway, if additional external through traffic shall so warrant.
(c)
Whenever possible, residential collector streets should be designed to have no residential lots directly fronting on them. When this is not possible, the amount of residential frontage per length of collector street length shall not exceed the limits set forth in the accompanying chart. In addition, only lots having frontages of 100 feet or greater may front on collector roads, and space shall be provided on these lots for turnarounds so that vehicles will not have to back out onto collector roads.
Collector ADT Level | ||||
|---|---|---|---|---|
<1,200 | 1,200-1,600 | 1,600-2,000 | >2,000 | |
% of allowable frontage taking access from collectors over entire length of collector street | 20% | 10% | 5% | none |
(d)
On-street parking shall be prohibited on residential collector street.
3.
Street Access. Every residential collector must be provided with no fewer than two access intersections to streets of equal or higher classification in the streets hierarchy.
4.
Street Width and Curbing. Curbs should not be provided along residential collector roads except as they are found to be essential for storm water management. Refer to Table of Street Design Options at the end of this section for determination of width.
5.
Shoulders. Three-foot wide stabilized turf shoulders are required along both sides of the residential collector street cartway.
6.
Moving Lanes. All residential collector streets shall be provided with a minimum of two moving lanes.
7.
On-Street Parking. On-street parking shall be prohibited on residential collector streets.
8.
Engineering Criteria. All features of the geometric design of residential collectors that are not specified below shall be designed for a speed of 40 miles per hour.
(a)
Minimum grade: 0.5%.
(b)
Maximum grade: 8%.
(c)
Horizontal curvature: minimum centerline radius of 350 feet.
(d)
Minimum tangent length between reverse curves: 150 feet.
(e)
Super elevation: 0.08 foot/foot.
(f)
Stopping sight distance: 275 feet.
(g)
Maximum grade within 50 feet of intersection: 3% minimum.
k.
Alleys.
1.
Alleys are not permitted in residential developments.
2.
Alleys shall be provided in commercial and industrial districts, except that the Planning Board may waive this requirement where other definite and assured provisions is made for service access, such as off-street loading, unloading, and parking consistent with and adequate for the uses proposed.
3.
The width of an alley shall not be less than 22 feet.
4.
Alley intersections and sharp changes in alignment should be avoided, but where necessary, corners shall be cut off sufficiently to permit safe vehicular movement.
5.
Dead-end alleys should be avoided where possible, but if unavoidable, shall be provided with adequate turnaround facilities at the dead-end, as determined by the Planning Board.
l.
Driveways.
1.
Access to Parking Areas.
(a)
All entrance drives serving three or less dwelling units or residential lots shall be, at a minimum, designed to single-family driveway standards as specified by this section.
(b)
All entrance drives which may be expected to convey less than 200 ADT volume or greater than five units shall be laid out to conform to the design, service, and access standards established in this section for local access streets and shall be considered a local access street for purposes of establishing the street hierarchy.
(c)
All entrance drives which may be expected to convey greater than 200 ADT but less than 1,000 ADT volume shall be laid out to conform to the minimum design, service, and access standards specified in this section for residential subcollector streets and shall be considered a residential subcollector street.
(d)
All entrance drives which may be expected to convey greater than 1,000 ADT volume shall be laid out to conform to minimum design, service, and access standards specified in this section for residential collector roads.