(A) Purpose and findings. The city finds that discontinuous street systems are inefficient. Channel traffic onto relatively few points of the transportation network causes undue congestion. A well-connected street network spreads traffic efficiently, provides greater opportunities for access by service and emergency vehicles and furthers pedestrian mobility by increasing the number of destinations that can be reached by walking. Accordingly, this section provides for both external and internal connectivity. External connectivity is promoted by requiring developers to connect to the existing street network. Internal connectivity is promoted by requiring a connectivity index for internal streets. The city acknowledges that there is a market for cul-de-sacs and streets with few connections. The connectivity index preserves the opportunity to provide cul-de-sacs while maintaining the integrity of the network as a whole.
(B) Connectivity index for internal streets. The streets within any proposed subdivision shall provide a connectivity index of at least 1.20. A use pattern established by Division 2 of this chapter may require a higher ratio. The connectivity ratio is computed by dividing the number of street links by the number of nodes within the subdivision. For purposes of this section, the intersection of a local street within the proposed subdivision with an arterial or collector street providing access to a proposed subdivision is not considered a node in computing the connectivity ratio. The connectivity ratio does not apply to minor subdivisions.
(C) Projecting streets. Where abutting areas are not subdivided, the arrangement of streets in the subdivision shall connect the streets to the unsubdivided areas. Parcels shall be arranged to allow the opening of future streets and logical further subdivision. Where streets change design in alignment and width, the street design shall provide a transition sufficient to ensure safe and efficient traffic flow. This section is not intended to require local streets to project into floodplains, bluffs or other natural features or existing development that has not made accommodations for connection. (See Figure 153.1068(A) below.)
Criteria | Bike Paths | Bike Lanes and Bike Routes |
Centerline radius | 300 | - |
Lane width (minimum, feet) | 10 | |
Included in street lanes with curbs and no on-street parking (bike lane only, measured from curb face) | 5 | |
Street lanes with on-street parking (minimum, feet, combined bike lane and parking stall) | 14 | |
Overhead clearance (minimum, feet) | 7.2 | 7.2 |
Right-of-way width (minimum, feet) | 14 | - |
Stopping sight distance (minimum, feet) | 250 | - |
NOTES TO TABLE: A dash (“-”) means “not applicable”. | ||
(D) Reserve strips prohibited. There shall be no reserve strips controlling access to land dedicated or intended to be dedicated to public use.
(E) Half-streets. In the case of collector or local streets, no new half-street rights-of-way shall be platted. Where the proposed subdivision abuts an existing half-street, the other half of the street shall be platted.
(F) Dead-end streets. Dead-end streets are prohibited, except as stubs to permit future expansion.
Maintaining connectivity from subdivision to subdivision in lieu of cul-de-sacs to create secondary road capacity.
(G) Non-access easement. Where the connectivity index required in subsection (B) above is not reduced, a vehicular non-access easement is permitted to control ingress and egress to vehicular traffic.
(H) Secondary access. At least one access point into a single-family residential subdivision shall be provided for every 2,640 feet (one-half mile) of frontage. Where a single-family residential subdivision exceeds 125 units, a secondary access will be required.
(Ord. 3020, passed 9-10-2013, § 5.23.4)