Title 3 — Development and Permitting, Chapter 360 — Infrastructure, Streets, Sidewalks, Multi-Use Paths, and Greenways
Street Classification and Right-of-Way Requirements
Table 360-1. Minimum Right-of-Way and Roadway Widths for New Streets and Project Access Improvements.
| Street Category | Minimum Right-Of-Way1 | Minimum Roadway2 |
|---|---|---|
| Principal Arterial | 120′ TO 150′ | 6 through lanes with median |
| Major Arterial | 100′ TO 120′ | 67′ |
| 4 to 6 through lanes with median | ||
| Minor Arterial | 80′ TO 100′ | 52′ TO 66′ |
| 4 through lanes with median | ||
| Major Collector | 80′ | 52′ |
| Minor Collector | 60′ TO 80′ | 28′ |
| Local Street Non-residential Non-residential Cul-De-Sac | 60′3 | 32′ |
| 60′ radius | 50′ radius | |
| Local Street Residential — Urban Residential — Urban Cul-de-sac | 50′ | 27′ |
| 50′ radius | 40′ radius | |
| Local Street Residential - Rural4 Residential — Rural Cul-de-sac4 | 60′5 | 24′6 |
| 60′5 radius | 40′ radius |
Non-residential 60′ radius 50′ radius Non-residential Cul-De-Sac Local Street 50′ 27′ Residential — Urban 50′ radius 40′ radius Residential — Urban Cul-de-sac Local Street 60′5 24′6 Residential - Rural4 60′5 radius 40′ radius Residential — Rural Cul-de-sac4 1The greater right-of-way width shall apply under circumstances as described in Section 360-10.2.
2Roadway width dimensions are back-of-curb to back-of-curb except where noted.
3Utility easement shall be provided in a location and size as required by the Department of Water Resources.
4Subdivisions zoned RA-200.
5May be reduced to 50 feet if curb, gutter, and piped drainage system is provided.
6Measured to edge of pavement. Curb and gutter is not required in RA-200 subdivision. Roadway width may be reduced to 23 feet if curb and gutter is provided (27 feet total width).
Requirements for New Streets and Roadways
Streets, whether public or private, shall be constructed or improved at least to the standards contained in this UDO in accordance with the category of said streets or as otherwise required by the Board of Commissioners.
Land in private ownership adjacent to public rights-of-way which could control or are intended to control access to streets, alleys, or public lands shall not be permitted unless their control is given to the County under ownership, dedication, or easement conditions approved by the County Attorney or acceptable to the Director. No development shall be designed so as to deny access to abutting properties.
Project Access Improvements
residential subdivisions.
Driveway Design Standards
Driveways shall generally intersect streets at right angles. The portion of a driveway located within a public right-of-way shall be paved. Driveways providing access to parking lots which contain five or more spaces shall be paved in accordance with the parking lot requirements in Chapter 240.
Driveways serving single-family detached or duplex residences may be no less than 10 feet wide at the right-of-way line and shall provide a radius to the back of curb or edge of pavement of the roadway of no less than 5 feet. Driveways shall provide a parking area of at least 18 feet deep measured from the edge of the sidewalk or curb if a sidewalk is not present or required. All other driveway curb cuts on public streets shall conform to the standards shown on the driveway details contained in the Standard Drawings in the Appendix of the UDO and by land use type as follows:
Along any Major Thoroughfare, a deceleration lane, acceleration lane, larger turning radius, traffic islands, or other devices or designs may be required to avoid specific traffic hazards which would otherwise be created by the proposed driveway location.
All driveways approaching a Minor Collector or Major Thoroughfare shall provide adequate corner sight distance, and shall meet or exceed the following design standards:
Based on the conditions, it may be feasible for the crossing maneuver to be done in two stages with a stop in the median. However, the intersection should only be treated in this manner if the signing and marking is accordingly provided. Otherwise, the sight distance requirements should be increased to account for the additional width that must be crossed. See A ASHTO Green Book, Chapter 9 Intersections, for adjustments due to grades greater than 3 percent and design vehicles other than passenger cars.
360-40.4 Corner Sight Distance SOL SOR o=:o CENTERPOINT OF CROSS LA~ E SPEED = LI MI I 01-C9.0SS ROAD PO I NT or Required RFQ UI R FO VEf-lC.E STOP Visibility Area Table 360-2. Sight Distance.
SPEED, 2 Lane 3 Lanes 4 Lanes 5 Lanes MPH SDL=SDR SDL SDR SDL SDR SDL SDR
25 280 280 295 280 310 295 335 30 335 335 355 335 375 355 400 35 390 390 415 390 440 415 465 40 445 445 475 445 500 475 530 45 500 500 530 500 565 530 600 50 555 555 590 555 625 590 665 55 610 610 650 610 690 650 730 60 665 665 710 665 750 710 795 65 720 720 765 720 815 765 860
All driveways except those serving residential units on individual lots shall meet the following criteria:
Table 360-3. Minimum Separation for Driveways, Public Roads, and Side Streets.
Posted Speed Minimum MPH Driveway Spacing 25 125 30 219 35 244 40 294 45 369 50 419 55 444 60 494 65 550
| District | Minimum driveway spacing (ft) |
|---|---|
| 25 mph | 125 |
| 30 mph | 219 |
| 35 mph | 244 |
| 40 mph | 294 |
| 45 mph | 369 |
| 50 mph | 419 |
| 55 mph | 444 |
| 60 mph | 494 |
| 65 mph | 550 |
Spacing shall be measured from centerline to centerline. If the Highway involved is a divided facility and the driveways do not align with a median crossover, the driveway spacing would only apply to the adjacent driveway on the same side of the Highway as provided in Table 360-3.
| District | 2-lane (SDL=SDR) | 3-lane SDL | 3-lane SDR | 4-lane SDL | 4-lane SDR | 5-lane SDL | 5-lane SDR |
|---|---|---|---|---|---|---|---|
| 25 mph | 280 | 280 | 295 | 280 | 310 | 295 | 335 |
| 30 mph | 335 | 335 | 355 | 335 | 375 | 355 | 400 |
| 35 mph | 390 | 390 | 415 | 390 | 440 | 415 | 465 |
| 40 mph | 445 | 445 | 475 | 445 | 500 | 475 | 530 |
| 45 mph | 500 | 500 | 530 | 500 | 565 | 530 | 600 |
| 50 mph | 555 | 555 | 590 | 555 | 625 | 590 | 665 |
| 55 mph | 610 | 610 | 650 | 610 | 690 | 650 | 730 |
| 60 mph | 665 | 665 | 710 | 665 | 750 | 710 | 795 |
| 65 mph | 720 | 720 | 765 | 720 | 815 | 765 | 860 |
Street Intersections
Intersections shall generally be at right angles and shall not be at an angle of less than 85 degrees, unless approved by the Department, nor less than 80 degrees unless the intersection is signalized, in which case the angle of the intersection may be reduced subject to the review and approval of the Gwinnett County Department of Transportation.
Street intersections should be designed with a flat grade wherever possible, but in no case should the grade exceed 2 percent in normal situations (or 4 percent in topographical hardship situations on local streets).
Horizontal Alignment.
Vertical Alignment.
| Approaching Street Category | Minimum Approach Distance |
|---|---|
| Principal Arterial | 100 Feet |
| Major Arterial | 100 Feet |
| Minor Arterial | 100 Feet |
| Major Collector | 75 Feet |
| Minor Collector | 75 Feet |
| Local | 50 Feet |
*Distance of the approach is measured from edge of pavement of the intersecting street to the point of curvature in the approaching street.
Intersection radii for roadways measured at back of curb and for the right-of-way lines shall be as set forth in Table 360-5 below. For intersecting streets of different classifications, the larger radii shall be provided. In all cases, adequate right-of-way shall be provided to maintain minimum of 11 feet from back-of-curb. Larger radii may be required for streets intersecting at angles less than 90 degrees.
| Street Category | Roadway Radii | R/W Radii |
|---|---|---|
| Arterial | 40 Feet | 20 Feet |
| Major Collector | 40 Feet | 20 Feet |
| Minor Collector-Residential | 25 Feet | 9 Feet |
| Minor Collector-Non-residential | 40 Feet | 20 Feet |
| Local Residential | 20 Feet | 9 Feet |
| Local-Commercial or Office | 25 Feet | 11 Feet |
| Local-Industrial | 40 Feet | 25 Feet |
*Intersecting right-of-way lines may be joined by an arc having the minimum radius shown, or by a miter which cuts across the right-of-way lines connecting the points where the required radius would have otherwise been tangent.
Islands in street intersections shall conform to the design requirements of the Standard Drawings in the Appendix of the UDO. In no case shall anything in an island extend more than three feet above the street grade within the right-of-way, except traffic regulatory devices and other infrastructure erected or approved by Gwinnett County. No island shall be approved which contains less than 100 square feet.
In all zoning districts, no fence, wall, structure, shrubbery, or other obstruction to vision between the heights of 3 feet and 15 feet, except utility poles, light or street sign standards or tree trunks shall be permitted within 20 feet of the intersection of the right-of-way lines of streets, roads, highways, or railroads.
Right turning lanes may be required to meet traffic demands or safety concerns. When provided, turning lanes shall meet the following criteria:
Street Design Standards
| Street Category | Maximum Grade | Design Speed |
|---|---|---|
| Principal Arterial | 8% | 60 MPH |
| Major Arterial | 9% | 50 MPH |
| Minor Arterial | 10% | 40 MPH |
| Major Collector | 10% | 40 MPH |
| Minor Collector | 10% | 30 MPH |
| Local | 15%* | 25MPH |
*Grades between 11 percent and 15 percent shall not exceed a length of 150 feet and shall require an "as graded"
survey prior to the installation of the curb or utilities. The distance shall be measured as the tangent length between points of curvature.
| Crest Curves | Sag Curves | |||
|---|---|---|---|---|
| Street Category | Minimum | Desirable | Minimum | Desirable |
| Principal Arterial | 151 | 320 | 136 | 155 |
| Major Arterial | 84 | 170 | 96 | 110 |
| Minor Arterial | 44 | 80 | 64 | 70 |
| Major Collector | 44 | 80 | 64 | 70 |
| Minor Collector | 19 | 30 | 37 | 37 |
| Local | 12 | 20 | 26 | 26 |
| Street Category | Minimum Radio (Ft.) | Maximum Superelevation |
|---|---|---|
| Principal Arterial | 1,333 | 0.06 |
| Major Arterial | 833 | 0.06 |
| Minor Arterial | 560 | 0.04 |
| Major Collector | 560 | 0.04 |
| Minor Collector | 300 | 0.04* |
| Local | 181 | 0.00 |
*No superelevation will be allowed on Minor Collectors internal to residential subdivisions
R = minimum radius curve v = vehicle design speed (MPH) e = rate of superelevation (decimal of a foot rise per foot roadway) f = side friction factor Vehicle Design Speed (v) 30 40 50 60 Side Friction Factor (f) .16 .15 .14 .12
| Street Category | Minimum Tangent Length | Desirable Tangent Length |
|---|---|---|
| Principal Arterial | 150 | 180 Feet |
| Major Arterial | 125 | 150 Feet |
| Minor Arterial | 100 | 120 Feet |
| Major Collector | 100 | 120 Feet |
| Minor Collector | 75 | 90 Feet |
| Local | 50 | 60 Feet |
Note: Minimum tangents are based on the distance traveled in 1.7 seconds at the design speed for each category of street. Desirable length is based on distance traveled in 2.0 seconds.
Street Construction Standards and Specifications
Unless otherwise specifically set forth herein, all of the materials, methods of construction, and workmanship for the work covered in reference to street construction shall conform to the latest specifications of the Georgia Department of Transportation.
Minor collectors or greater shall be constructed in accordance with designs prepared by Gwinnett County or Georgia DOT, or, if no design has been prepared, to the following standards:
Curbs and Gutters
All new streets and Project Access Improvements shall be provided with curb and gutter except in subdivisions zoned RA-200, where swale ditches may be provided in lieu of curb and gutter. All gutters shall drain smoothly with no areas of ponding.
Residential curbing shall meet the following requirements:
Industrial or commercial curbing shall meet the following requirements:
Collector and Arterial curbing shall meet the following requirements:
Sidewalk Requirements
Sidewalks and curb ramps shall be constructed in all new development or redevelopment along all abutting or internal streets, existing or new, private, or public. Whenever a discrepancy occurs between the design and construction standards of this UDO and any state or federal regulation, then the most restrictive shall apply.
the requirements of this section. The Director is authorized to grant Modifications upon specific application due to topographic or drainage difficulty as well as alternative design proposals after receiving a recommendation from the Department of Transportation.
Multi-Use Path Requirements
is shown with roadway frontage along a roadway that is classified as being within the Gwinnett Countywide Trails Master Plan, the developer shall be responsible for the construction of a minimum 12-foot trail along the road frontage. The developer/builder shall coordinate with the Department of Transportation for location and approval. Where provided multi-use paths shall comply with the provisions of this section as well as the provisions contained in Chapter 360 of this UDO and shall meet the following requirements:
Multi-use trails and paths shall be a minimum of 12 feet in width.
Greenway Requirements
Master Plan Trails Master Plan. Greenways, where provided, shall comply with the provisions of this section as well as the provisions contained in Chapter 360 of this UDO and shall meet the following requirements:
County Maintenance. The County will accept maintenance responsibility similar to its maintenance for County-owned park property, for a greenway if the Director of Community Services or designee finds all of the following:
these responsibilities are accepted by the County. Where the applicant retains maintenance responsibilities, the greenway must be maintained at a level at least equal to those design standards as required by the Gwinnett Countywide Trails Master Plan.
Traffic Control Devices
Street signs, traffic control signs, and devices such as striping and signalization, shall be provided through payment of fees to the Department of Transportation for the installation thereof.
Public street name signs shall have a green background with white legends mounted on channelized posts. Private street name signs shall have a blue background with white legends mounted on channelized posts. Alternate post material shall be subject to the review and approval of the Department of Transportation. The posts and signs will be furnished and installed by the County at all street intersections. The developer (or homeowners association in the event an alternate signpost is chosen at a later date) shall pay the County's costs.
All traffic signals and signs shall conform to the Manual on Uniform Traffic Control Devices (no decorative traffic control devices will be allowed) or as per Gwinnett County Department of Transportation.
All newly constructed streets having four or more lanes (including auxiliary lanes) and existing streets being widened with one or more additional lanes shall be striped or the payment of said striping costs shall be required from the Developer by the Department of Transportation prior to the Approval of Development Conformance for the project. Striping shall be accomplished with paint meeting Georgia Department of Transportation standards conforming to the Manual on Uniform Traffic Control Devices.
Payment for materials and installation of street name and traffic control signs in new developments shall be required by the Department of Transportation prior to the approval of the Final Plat for new subdivision streets and the Approval of the Development Conformance for all other developments.
Traffic Calming Devices
Guide. The maximum length of roadway section between speed control points, as defined by the Traffic Calming Guide, shall be 500 feet.
The Director of the Department of Transportation may grant modifications.
Private Streets and Alleys
Application for approval of such private alleys may be considered by the Director of the Department of Planning and Development.
Maintenance responsibility by Gwinnett County for individual sanitary sewer stubs shall extend to the end of the standard six-inch stub, and to the water meter for individual water lines.
No Final Plat involving a private street shall be approved by the Department for recording unless and until it shall contain the following on the face of the plat:
Signature of Property Owner Date
Alley.
"Purchaser's Acknowledgement of Private Street and/or Alley and Drainage Maintenance Responsibility."
Purchaser Date Purchaser Date