(a) Roadway network. Prior to plat approval the city shall determine whether the roadway network serving the development to be platted has adequate capacity to accommodate existing traffic, traffic reasonably anticipated from the development, and traffic reasonably anticipated from other developments approved or for which a formal application has been submitted. Adequate connectivity will address internal connectivity as well as external connectivity. This determination shall be based on information provided by the developer in the plat application and supporting studies, unless the study is waived.
(b) Vehicular paved access to subdivisions.
(1) Vehicular access to subdivisions within the city shall be by means of a public street having an all weather reinforced concrete or HMAC asphalt paved surface, constructed to city standards, and of appropriate design, traffic capacity and service level rating to accommodate the present and anticipated traffic volumes and wheel loads of passenger, sanitation, moving vans, delivery services and emergency vehicles and equipment. Failure to meet, or provide satisfactory proof of meeting these requirements, by the developer, prior to the construction of on-site buildings, shall be basis for denial of any required building or related permit.
(2) Vehicular access to subdivisions within the ETJ area of the city shall be by an approved paved all weather hard-surfaced street, meeting the design standards of the city or as depicted in an adopted city/county inter-local agreement.
(c) Secondary ingress and egress to subdivisions.
(1) Subdivisions containing more than 30 one-family or two-family dwelling units shall have a platted and constructed secondary ingress and egress to a public street. Multi-family developments of 100 dwelling units or more shall have a platted and constructed secondary ingress and egress to a public street.
(2) Development phasing of any subdivision shall ensure that all such residential units have a platted and constructed secondary entrance when more than 30 residential units are proposed.
(3) Subdivisions with up to 40 one-family or two-family dwelling units may be permitted with one access point if a platted and constructed secondary entrance will connect to future development.
(d) Internal roadway network connectivity.
(1) All proposed developments shall have a connectivity index of 1.4 or greater. The connectivity index shall be calculated by dividing the total number of links (streets including stub-out streets) by the total number of nodes (intersections, culs-de-sacs, no-outlets, dead-ends).
(2) Stub outs to adjacent property are worth one-half credit each toward the number of links. Residential road connections to collector streets and larger are worth one full credit each. Standard public access easements count as links. Culs-de-sac count as links.
(3) Street elbows do not count as nodes. Standard alley intersections do not count as nodes. Intersections on collector streets and larger do not count as nodes. The termination of culs-de-sac count as nodes.
(4) Link-to-node connectivity index.
Ratio = 7/8 = 0.88 Ratio = 13/9 = 1.44
(5) The city plan commission may grant waivers to these requirements only upon finding that the development is constrained by topographic features, existing development or other impassible features.
(e) External roadway network connectivity. Subdivisions shall be phased in such a way to ensure effective traffic management. Applications for subdivisions including five or more lots shall include a traffic management plan, which shall include at a minimum: the estimated number of phases; the necessary improvements to ensure adequate access; the trigger point(s) for providing the improvements; and the number of lots that will be included in the corresponding phases.
(f) Secondary ingress and egress shall be in conformance with § 31-101(c). Above the second access point, the accumulated estimated peak hour traffic volumes for each public street connection shall not exceed the following:
Street Classification | Peak Hour Traffic Volumes |
Local | 350 vehicles per hour per lane (vphpl) (each direction) |
Collector | 750 vphpl (each direction) |
Industrial | 750 vphpl (each direction) |
(g) Collector network planning. All new preliminary plats shall show a collector network consistent with these requirements. Final minor plats contained within or adjacent to the planned or existing collector network shall connect with the collector network.
(1) Collector design is a careful balance between providing direct connectivity and attracting no more traffic than is appropriate. The primary means of achieving this balance is through proper subdivision network layout design, which considers each internal roadway's tributary area (the streets and homes that feed it), the daily number of vehicle trips generated by a typical home, and the resulting expected daily traffic on the key internal streets.
Example Collector Street Network
(2) Collector streets shall provide continuous access between thoroughfares, but discourage long-distance through traffic. The definition of long distance varies with context; Figure 4 indicates the target trip length and upper-limit traffic volumes for each context.
(3) Collector streets serve both residential and non-residential land-uses. However, they shall be planned and designed to discourage non-residential (i.e. commercial, industrial) traffic intrusion into residential areas.
Figure 4
Residential area | C. Non-residential/ mixed-use areas | ||
A. With fronting single-family homes* | B. No fronting single-family homes | ||
Typical trip length | ½ mile | 1 mile | up to 2 miles |
Upper limit daily traffic volume (both directions) | 2,000 | 5,000 | 10,000 |
Applicable design features to promote these characteristics (see text) | Curvilinear design; traffic-calming treatments | Roundabouts; discontinuities | Curvilinear design; roundabouts |
On-street parking | Required | Allowed but not required | Allowed but not required |
*Collectors without fronting homes are preferred | |||
(4) Collectors shall only terminate at an intersection with a thoroughfare or another collector except when the collector is a stub, that when ultimately finished will make this connection.
(5) Collector streets shall connect to thoroughfares at full median opening locations in accordance with the requirements of the Access Management Manual where feasible. The connection shall also be made at a location suitable for a future traffic signal installation.
(6) Collectors shall align across thoroughfares rather than forming offset intersections (to promote safe, efficient traffic flow on the thoroughfare). The city plan commission may grant a waiver if analysis determines that applying this approach will encourage cut-through traffic and/or undesirably long trips on a specific collector. Figure 4 indicates the typical trip lengths.
(7) At jurisdictional boundaries, collector planning and design must coordinate with the adjacent jurisdiction to maximize the ability to meet Fort Worth's policies and needs while supporting the adjacent jurisdiction's policies and needs.
(8) Design features shall encourage speeds of 25 mph or less and provide visual cues to drivers that the street is not intended for long-distance trips.
(9) If a subdivision network layout alone is insufficient to achieve the characteristics above, especially on collectors fronted by homes, special design approaches shall be incorporated. Traffic engineering studies can predict or estimate the effects of many of the design approaches described below, especially the effects on traffic volumes. If these measures are not sufficient to achieve the desired characteristics, then larger building setbacks and/or landscaping along the street shall be considered to buffer residences fronting on higher-volume collector streets. Design features to discourage speeding and long-distance trips:
a. Curvilinear street design: Curvilinear design reduces speeds, gives the road a meandering feel, and supplies a visual cue (if curvature is visible from intersections) that speeds are lower and unsuitable for cut-through traffic.
b. Neighborhood entry features: For residential collectors that have fronting homes and that cross thoroughfares, neighborhood entry features - including treed entry medians and entry signage - send visual cues that the street is intended for neither through traffic nor desirable for that purpose.
c. Traffic calming measures: These measures are most appropriate on residential collectors with fronting homes. They can include such items as on-street parking, roundabouts, mini-roundabouts, chicanes, and raised crosswalks.
d. Discontinuities: The design approaches listed above are generally sufficient to discourage cut-through traffic and promote desirable collector function. For cases in which these measures are deemed through analysis to be inadequate, discontinuities (Figure 5) may be considered. Discontinuities generally make thoroughfare access unnecessarily difficult for local travelers. Therefore, the discontinuity treatments described below shall only be considered if the above design approaches are shown, via traffic engineering analysis, to be unable to provide volume and trip-length limits appropriate to their context as described in Figure 4.
1. L-shaped collectors. This approach discourages cut-through traffic with a collector that connects intersecting thoroughfares rather than parallel thoroughfares.
2. Offset thoroughfare crossing. This approach puts a jog in the collector where it intersects the thoroughfare. This approach decreases pedestrian access and comfort and increases the number of intersections on the thoroughfare.
3. Internal offset. This approach puts a jog in between the thoroughfares connected by the collector.
4. Internal gap. This approach creates deliberately circuitous navigation through the neighborhood.
Figure 5: Discontinuities
(10) Collector streets shall be spaced accordi ng to Figure 6, subject to consistency with the Access Management Policy, unless natural or man-made features pose constraints. When planning and designing a collector layout:
a. Avoid steep slopes and otherwise unsuitable topography.
b. Minimize impact to the built environment.
c. Minimize wetland and floodplain impacts (i.e., identify 90-degree stream crossings at the narrowest point possible), critical watershed areas, and stream crossings.
d. Avoid railroad crossings and bisecting parks.
e. Minimize impacts to utilities (e.g., gas wells).
(11) The city plan commission may grant waivers to these requirements only upon finding that the development is constrained by topographic features, existing development, or other impassible features. The city traffic engineer or designee may administratively modify the spacing requirements within 10% or 100 feet (whichever is less) where it is impractical to meet the standards.
Figure 6
Land Use | Dwelling Units/Acre | Access Function | Desired Maximum Spacing between Collector Intersections along a Thoroughfare (feet) |
Rural | < 2 | N.A. | N.A. |
Residential Suburban | 2 - 4 | High | 1,500 - 3,000 |
Urban | > 4 | High | 750 - 1,500 |
Non-Residential and Mixed Use | n.a. | Medium | 750 - 1,500 |
(Ord. 17794, § 9, passed 9-25-2007; Ord. 17851, § 1 (App. C, Ch. 6, Art. I), passed 10-30-2007; Ord. 22051-01-2016, §§ 1 - 4, passed 1-12-2016; Ord. 23225-06-2018, § 2, passed 6-5-2018, eff. 8-1-2018)