(A) General requirement. In order to provide subdivision streets of suitable location, width and construction; and to afford access to police, fire fighting, snow removal, sanitation and road maintenance equipment; and to coordinate subdivision street development with the existing street system and the Comprehensive Plan, all subdivision streets in the secondary plat submitted for approval shall be designed in accord with the standards set forth in this section, as amended from time to time, as well as the city specifications adopted by the Board of Public Works and Safety, as amended from time to time. In the event that mere is a conflict between this chapter and the Specifications adopted by the Board of Public Works and Safety, the more restrictive standard shall apply.
(B) Arrangement standards. The layout of subdivision streets shall conform to the following:
(1) Local streets shall be so arranged as to discourage their use by through traffic.
(2) Subdivision streets shall extend to the boundary lines of the subdivision tract and be installed as stub-streets in order to provide for their future extension into adjacent areas.
(3) Streets and access ways in business and industrial developments shall be planned in connection with the grouping of buildings, the location of rail facilities, and the provision of alleys, truck loading and maneuvering areas, walkways, and parking areas so as to minimize conflict of movement between the various types of vehicular and pedestrian traffic.
(4) All streets and alleys shall have a clear vertical clearance from the roadway surface to any overhead obstruction of at least 15 feet.
(C) Intersection standards. The following standards shall apply to all subdivision street intersections:
(1) With the exception of roundabouts, the centerlines of intersecting streets shall intersect as near as possible at right angles (90 degrees), in which case the intersecting angles of said streets shall be no less than 75 degrees. All intersections are subject to approval of the Plan Commission.
Figure 1: Intersection Centerlines and Angles
(2) The simultaneous intersection of streets resulting in traffic from more than four streets is prohibited.
(3) The property, or right-of-way lines, of comer lots at street intersections shall be rounded at the comer with an arc, of at least 15 feet minimal radius, drawn tangent to each of the intersection property lines.
(4) The minimum distance between the centerlines of parallel or approximately parallel streets intersecting a cross-street from opposite directions shall be 125 feet.
(5) The maximum slope approaching an intersection shall be 8%.
Figure 2: Distance between Cross-streets
Figure 3: Minimum Radius
(D) Curves. The following standards shall apply to all subdivision street curves:
(1) When the street centerlines deflect more than ten degrees, the minimum radius of horizontal curvature, measured on the centerline of the street, shall be:
Table 1: Minimum Radius of Horizontal Curvature
Category | Minimum Radius in Feet |
Arterial | 600 |
Collector | 400 |
Local | 200 |
Cul-de-sac | 100 |
Alley | 100 |
(2) The minimum tangent distance between reversed curve shall be:
Table 2: Minimum Tangent Distance Between Reversed Curve
Category | Minimum Tangent in Feet |
Arterial | 500 |
Category | 350 |
Collector | 200 |
Local | 100 |
Cul-de-sac | 100 |
Alley | 100 |
Figure 4: Minimum Tangent Distance
(E) Topography.
(1) Subdivision streets shall be arranged in proper relation to the topography in a manner which results in usable lots, safe streets and acceptable gradients; and in a manner which does not cause unnecessary destruction of drainage courses, trees and other natural features of the land.
(2) Rectangular, “gridiron” streets shall be avoided, and the use of curvilinear streets shall be encouraged where such use will result in a more desirable layout and topographical relationship. Innovative, varying geometrical street patterns shall be encouraged where such provide a sense of order and enhance esthetic interest.
(3) Right-of-way widths in excess of the standards specified by these regulations shall be required whenever additional width is necessary, due to topographical conditions, to provide for adequate and stable earth slopes. Such slopes shall not be in excess of a three to one (3:1) height to width ratio.
(F) Alleys. Alleys may be allowed in all commercial and industrial districts. Alleys shall not be permitted in residential districts except where justified by unusual conditions or consistent with the proposed development pattern.
(G) Cul-de-sacs/dead end streets. Cul-de-sacs shall not be permitted in any district where such are in conflict with the Comprehensive Plan. No permitted cul-de-sac shall provide principle frontage to more than 20 lots or be longer than 500 feet, including a turn-around, whichever is less. Whenever a collector street exclusively serves an industrial or commercial area, a cul-de-sac of up to 1,000 feet in length may be allowed. This special provision shall be allowed only in areas where access is difficult or which are otherwise unsuitable for normal subdividing. The minimum radii for cul-de-sacs shall be as prescribed in the city specifications adopted by the Board of Public Works and Safety, as amended from time to time.
(H) Continuation of streets, alleys and easements. Whenever a dedicated or platted portion of a street, alley or easement exists adjacent to a proposed subdivision, the continuation of the street, alley or easement right-of-way at the prescribed width, shall be platted within said subdivision unless the Commission deems such continuation unnecessary.
(I) Minimum right-of-way and pavement widths. Subdivision streets and alleys shall be designed in accordance with the city specifications adopted by the Board of Public Works and Safety, as amended from time to time.
(J) Construction standards. All subdivision streets shall be constructed according to the following standards:
(1) Subdivision streets shall be completed to the grades specified on their respective plans, profiles and cross-sections as approved by the Commission.
(2) The minimum specifications for subdivision street construction and materials shall be as set forth in the applicable sections of the “Crawfordsville Standards,” as amended from time to time, except where the Commission has by rule adopted a different set of standards and specifications, or as required in this chapter. Street surfaces shall be of a character suitable for expected traffic and shall be in harmony with similar improvements in the surrounding area.
(K) Railroads and limited access highways. If a proposed subdivision plat adjoins a railroad right- of-way and/or a limited access highway, the following requirements shall apply:
(1) In all residential districts, a buffer strip of at least 25 feet in depth, in addition to the normal lot depth required for such districts by the Zoning Code in Chapter 153 and amendments thereto, shall be provided adjacent to the railroad right-of-way or limited access highway. This strip shall be part of the platted lots and shall be designated on the submitted preliminary plat as follows: “This strip is reserved for screening. The placement of structures hereon, other than earth berms, walls, fences and other landscape screening devices approved by the Commission is prohibited.”
(2) In all districts, streets running parallel to a railroad right-of-way shall be located at least 150 feet from said right-of-way upon intersecting with a street which crosses the railroad at grade.
(L) Street names. Subdivision street names shall not duplicate any existing street name within the county except in the case of a direct extension. Street names that are spelled differently from, but sound the same as, existing streets shall not be allowed. In no instance shall any street name include the word north, south, east or west, unless it denotes a geographic location. In event of a conflict, the Plan Commission shall have final authority to name all streets upon granting preliminary or secondary plat approval.
(M) Street dedications and reservations.
(1) All subdivision streets shall be dedicated to public use. The Commission may consider allowing private streets in the event of unusual physical conditions and if the applicant can provide evidence that a private street is the only feasible solution. Such private streets may be authorized provided that the standards applied in their construction comply with this section and the city specifications adopted by the Board of Public Works and Safety, and that adequate covenant provisions are made for direct responsibility and control, by the property owners involved, for the perpetual operation, liability and maintenance of said private streets at no expense to the city.
(2) Subdivision street systems shall be laid out in a manner which eliminates or avoids new perimeter half-streets. When an existing half-street is adjacent to a new subdivision, the other half of the street shall be improved and dedicated by the applicant. The Commission may authorize a new perimeter street where the applicant improves and dedicates the entire required right-of-way width within his own subdivision’s boundaries.
(3) Whenever a proposed subdivision borders an existing street, the Commission may require the reconstruction or widening of such street as a condition of preliminary or secondary plat approval. Land reserved for any street purposes may not be counted in satisfying the yard or area requirements of the Zoning Ordinance in Chapter 153 or amendments thereto.
(Ord. 5-2009, passed 3-9-09)