[Ord. No. 472-01 §1, 12-17-2001; Ord. No. 667 §1, 11-7-2011]
All new streets, curbs, gutters and sidewalks built within the City of Strafford, Missouri, shall be subject to the specifications set out in this Article, together with the terms and conditions set forth on said specifications.
This Article shall apply to all said street, curb, gutter and sidewalk improvements made after November 7, 2011.
Note — There were drawings attached to ord. no. 472-01, which are as follows: typical street sections; concrete pavement joint details; parking stall layout elements; concrete driveway detail; concrete sidewalk detail; concrete street detail; concrete street repair; asphalt street repair; standard barrier concrete curb and gutter; concrete pavement joint details; concrete pavement joint location; curb ramp Type I; curb ramp Type II; mid-street curb ramps; standard cul-de-sac for local street and cul-de-sac detail. These drawings are set out in the Attachment to this Chapter.
[Ord. No. 472-01 §1, 12-17-2001; Ord. No. 506 §§1 — 2, 3-3-2003; Ord. No. 667 §1, 11-7-2011]
Specifications for street construction shall be as follows:
Streets shall be completed in accordance with the plans, profiles, specifications and cross sections prepared for the subdivider by a Missouri registered professional engineer and approved by the City Administrator.
The streets shall be surfaced to a minimum width according to the type of street as specified in standard street details on file in the City offices and made a part of this Article by reference.
All work must be done under the supervision of the Strafford Street Department.
The streets shall be graded, surfaced and improved to the dimensions required by the cross sections and work shall be performed in the manner prescribed to by the City Administrator or City Engineer. Streets shall be surfaced to a minimum width as listed in the table below. Grading for street improvements shall not create soil slopes exceeding a vertical rise of one (1) foot for each three (3) feet of horizontal distance unless retaining walls are to be provided. Street pavement width shall be measured from back of curb to back of curb.
Prior to the construction of street or alley pavements, adequate surface and subsurface (if required) drainage facilities shall be installed by the subdivider. Pipe used for drainage purposes shall be of corrugated metal, HPDE or reinforced concrete, size and strength to meet the requirements of the specific conditions which may be encountered. Minimum diameters of pipe to be used shall be as follows:
Declaration from a Missouri registered professional engineer in a manner acceptable to the City Administrator that all construction is completed in accordance with the specific conditions in the agreement for improvements and the accepted plan and specifications are required before a street can be dedicated for public use. When changes from the accepted plans and specifications become necessary during construction, written approval from the City Administrator shall be secured prior to the execution of such changes.
Adequate provision for the maintenance of all street improvements shall be made by dedication to and acceptance for maintenance by the City Council.
Typically, street construction shall proceed as follows:
Rolled stone base. Rolled stone base shall consist of crushed stone (MoDOT Type 1 aggregate base) constructed on a prepared subgrade to the line, grade, thickness and typical cross section shown in the standard street details.
This base shall be constructed at the contractor's option of two (2) layers of compacted thickness totaling six (6) inches or in one (1) six (6) inch layer of compacted thickness. The aggregate shall be produced from limestone obtained from an approved source. The crushed stone may contain deleterious material, such as shale or disintegrated stone, not to exceed fifteen percent (15%).
Moisture content. Water necessary for proper compaction and to prevent segregation may be added at the crushing plant or added to the crushed stone after it has been delivered to the roadbed. In either case, the water shall be uniformly mixed with the crushed stone before compaction is started. The amount of water to be used shall be sufficient to insure the required density. Excess moisture shall be avoided.
Spreading, shaping and compacting. In no case will the contractor be permitted to place the mixture or manipulate it on muddy or frozen subgrade. Also, any mixture containing frost or frozen particles shall not be placed on the subgrade or compacted.
After the subgrade has been properly prepared and compacted, the mixture shall be uniformly spread by blades in successive layers or courses to such depth that when compacted, the base will have the minimum thickness shown on the typical cross section. The contractor may construct the base of any number of layers that he finds most convenient to facilitate mixing and compacting except that in no case shall any individual layer have a compacted thickness of more than six (6) inches. Each layer shall be compacted as hereinafter specified before any succeeding layer is placed.
Except as otherwise permitted by the City, the first (1st) course placed upon the subgrade shall be compacted and allowed to become firm before any subsequent layer is constructed.
If, in the opinion of the City, the mixture becomes too dry to properly complete compacting operations, water shall be added during these operations in such an amount as to insure proper compaction. If, for any reason, the mixture is too wet for proper compaction, it shall be allowed to dry until proper moisture content has been obtained.
The mixture shall be handled in such manner as to avoid undue segregation. If segregation occurs or if the mixture becomes contaminated, such segregated or contaminated materials shall be removed and replaced with materials of suitable quality and graduation, except that areas of surface segregation may be corrected by spreading sufficient limestone screening to close the voids and bind the loose material firmly in place. The screening shall be wet and rolled so as to create a dense and uniform surface. Segregated or contaminated materials, which the City orders removed, shall be removed and replaced with suitable material at the sole expense of the contractor.
Shaping and compaction shall be carried on until a true, even, uniform base course of proper grade, cross section and density is obtained.
Proper moisture content shall be maintained by wetting the surface as required during shaping and compacting operations. The uses of excess water resulting in runoff or in the formation of a slurry on the surface shall be avoided.
The density to be obtained in the completed base shall be at least ninety-five percent (95%) of maximum density as determined by the standard compaction test.
Maintenance. When the base is constructed in more than one (1) course, the contractor shall maintain the underlying course or courses by wetting, blading and rolling in a manner satisfactory to the City until such time as the course is thoroughly cured.
Primer. When base is thoroughly cured throughout its entire thickness, approved primer is to be applied. Apply with an approved distributor. No base course shall be primed unless it has been inspected and approved by the City.
Asphaltic concrete surfacing. Asphaltic concrete shall meet the requirements of the latest edition of the Missouri Standard Specifications for Highway Construction published by the Missouri Department of Transportation (MoDOT) and approved by the City.
Surfacing shall be laid with an approved spreading and finishing machine to the line grade and thickness as shown on typical sectional plans.
Final rolling with smooth-wheeled roller.
No asphalt shall be laid when temperature falls to fifty degrees Fahrenheit (50°F).
Ditches And Drainage. All ditches providing drainage for streets constructed as hereinabove set forth shall be sloped and graded to provide for adequate drainage of reasonably anticipated surface water runoff, considering the terrain and contour of the land traversed by said street; contractor shall be responsible for the grading and seeding of such ditches so as to prevent erosion and to facilitate mowing and maintenance by the City.
Utility Lines. All street service connections of street-located utility lines, such as gas, water and sewer, are to be stubbed out to the adjacent property lines at the expense of the contractor.
Use Of Streets Under Construction. No person shall ride, drive or lead any horse, mule or other animal or run, push or drive any vehicle over, on or across any street or part thereof while it is in the actual course of construction or being improved in such a manner as to in any way damage, injure or displace any curbing, guttering, paving, macadamizing, grading or other improvement being done.
Excavations. No person shall dig or excavate on or under any street, avenue, alley or sidewalk in this City for any purpose whatever without having first obtained a permit from the City Clerk. Every person making or causing to be made any such excavation shall replace the earth taken therefrom and shall fill such excavation with the same type of material as surrounding area to the slope, grade or compaction and shall reseed, when applicable.
Culverts. Only prescribed corrugated metal, HPDE and reinforced concrete piping which has been approved by the City shall be used. The use of barrels, hot water heaters or other substitutes for the prescribed steel, plastic and concrete piping is prohibited.
Culverts must be of sufficient diameter to carry water runoff but not less than a fifteen (15) inch diameter unless a smaller culvert is authorized in writing by the Board of Aldermen of the City of Strafford, Missouri. Culvert must include flared end sections on each end beyond driveway or street surface.
The installation and maintenance of culverts in a new addition shall be the responsibility of the developer.
Items Prohibited In Ditch Or Ditch Lines. Dumping of trash, leaves, ashes or other debris into ditches is prohibited. Driving or parking of vehicles in or across ditches is prohibited. Burning of leaves in ditches is prohibited.
Modifications to the current construction standards to permit "green" development or "sustainable" development may be permitted on a case-by-case basis upon review and approval by the City Engineer and the Board of Aldermen. If approved, the modifications shall be thoroughly documented and shall become a part of the permanent record of the development so the effectiveness of the modifications may be monitored.
[Ord. No. 667 §1, 11-7-2011]
The grades of streets shall not exceed the following except that, where unusual exceptional conditions exist, the Planning and Zoning Commission may modify these requirements. However, in no case may streets be constructed with grades that, in the professional opinion of the City Administrator or City Engineer, create a substantial danger to the public safety.
Arterial — Five percent (5%) maximum.
Collector Streets — Eight percent (8%) maximum.
Local Streets, Service Drives and Alleys — Ten percent (10%) maximum.
Pedestrian Ways or Crosswalks — Twelve percent (12%) maximum unless steps of an acceptable design are to be constructed.
Minimum Grade — In no event shall the minimum grade of any street be less than one-half of one percent (0.5%).
Length of Vertical Curves — The length of vertical curves shall be no less than that determined by the formula:
L = KA, where:
L = length of vertical curve
A = algebraic difference in grades
K = determined by the following table
[Ord. No. 472-01 §1, 12-17-2001; Ord. No. 667 §1, 11-7-2011]
Curbs and gutters are required for all streets.
Curbs and gutters shall be constructed in conjunction with the street pavements on all streets and shall be of Portland cement concrete at least thirty (30) inches wide and not less than six (6) inches thick where the curb abuts the street pavement in accordance with the standard street details.
Curb construction for concrete pavements may be integral, standard ninety degree (90°) curbs.
All plans for the installation of the curb and gutter shall be approved by the City Administrator or City Engineer.
[Ord. No. 472-01 §1, 12-17-2001; Ord. No. 667 §1, 11-77-2011]
Sidewalks shall be provided within a subdivision on one (1) side of local and collector streets and on both sides of arterial streets. Sidewalks shall be of Portland cement concrete with a minimum thickness of four (4) inches on a four (4) inch gravel or crushed stone base and a minimum width of four (4) feet, and the edge of walks shall be adjacent to the property line.
Crosswalks within the blocks shall be a four (4) foot walk of Portland cement concrete four (4) inches thick on a four (4) inch compacted aggregate base. The base shall be extended beyond the sidewalk on either side to a distance equal to depth of base.
If for any reasons sidewalks are not provided, the street grade shall be completed so that additional grading would not be necessary for any future provision of sidewalks and a performance guarantee shall be provided for future installation of sidewalks.
Curb ramps in accordance with the Standard Street Details and meeting current ADA requirements shall be provided at all intersections and crosswalks.
[Ord. No. 207-91 §§1 — 4, 8-8-1991]
Street Names — Official Map. The City of Strafford hereby names and designates the streets within the City. The official map designating the name of each street will be located in the City Hall for public inspection during business hours. A copy of said map is on file in the City offices and is incorporated herein by reference.