The following standard will apply to each and every street hereafter constructed in the city. Definite and detailed specifications and plans shall be prepared for each individual project based upon its own location and special features. The detailed specifications and plans shall be in accordance with this general outline and Minnesota Department of Transportation (Mn/DOT) standards as applicable.
(1) General Design Standards.
(a) Widths. Street right-of-way widths shall not be less than as follows:
Minor Arterial 120 feet
Collector Street 80 feet
Local Street 60 feet
Commercial and/or Industrial 80 feet
Service Drive (except for service 60 feet
drive adjacent to principal arterial)
Cul-de-sac 60 feet radius
In cases where any temporary or permanent street has a right-of-way width less than 60 feet, the design and specifications for construction shall be considered as special. The design of such street shall be in such a way as the City Engineer deems best for the contemplated use. The petitioner shall be required to enter into special agreements pertaining to the construction of these streets.
(b) Intersections. Insofar as practical, streets shall intersect at right angles. In no case shall the angle formed by the intersection of two streets be less than 60 degrees. Intersections having more than four corners shall be prohibited. Adequate land for future intersection and interchange construction needs shall be provided for.
(c) Deflections. When connecting street lines deflect from each other at one point by more than ten degrees, they shall be connected by a curve with a radius adequate to ensure a sight distance of not less then 500 feet for arterials, 300 feet for collectors, and 100 feet for all other streets. The council may allow greater or lessor sight distances at the recommendation of the City Engineer.
(d) Street Jogs. Street jogs with centerline offsets or less than 125 feet shall be avoided
(e) Access to Arterials. In the case where a proposed plat is adjacent to an arterial street, there shall be no direct vehicular or pedestrian access from individual lots to arterials unless unavoidable in the opinion of the City Council. Where direct access is deemed necessary, access shall included special requirements for turn around space on the lots, combination of driveways to the extent possible, and any other requirements of the roadway. As a general requirements, access to arterials shall be at intervals of not less than one-forth mile and through existing and established cross roads, where possible.
(f) Local Streets. Local streets shall be laid out so that their use by through traffic will be discouraged.
(g) Hardship to Owners of Adjoining Property. The street arrangements shall not be such as to cause hardship to owners of adjoining property in platting their own land and providing convenient access to it.
(h) Cul-de-sacs. Cul-de-sac use shall be held to a minimum. Cu-de-sacs when used shall be held to as short a distance as possible. The maximum length of a cu-de-sac shall be 500 feet, measured from the centerline of the street of origin to the end of the right-of-way. Islands in cul-de-sacs shall not be allowed.
(i) Half Streets. Half streets shall be prohibited except where it will be practical to require the dedication of the other half when the adjoining property is subdivided, in which case the dedication of a half street may be permitted.
(J) Private Streets. Private streets shall not be permitted, nor shall public improvements be approved for any private streets.
(2) Detailed Design Standards.
(a) Pavements. The minimum standard for pavement design shall be as follows:
1. Soil borings for each new street or improved street shall be required to facilitate design and provide bidding information to the construction contractor. The location and minimum number of such borings shall be as required by the City Engineer on each project.
2. A Stabilometer R-Value shall be determined from the soils engineer and his calculations presented to the City Engineer. Because of the generally high and variable water table in Lino Lakes, the R-Value shall consider the worst possible soil moisture conditions.
3. The R-Value shall be used to determine the necessary thicknesses of the gravel base, bituminous binder course, and bituminous wearing course.
4. Streets shall be kept three feet above the water table and design flood level of adjacent ponds, as measured from finished grade, where soil borings or other data indicates that the street subgrade may become saturated within three feet of the finished street grade. Special construction methods such as use of select granular borrow subbase and/or properly designed drain tile may be employed as an alternative with the approval of the City Engineer.
5. All residential streets being constructed or improved shall be designed for a minimum of seven ton design loading and shall be capable of carrying a minimum of 400 motor vehicles per day. If more than 400 vehicles per day are anticipated, base and pavement design shall consider the projected traffic. Collector, commercial and/or industrial streets shall be designed for nine ton loading.
6. Subase, as necessary to meet the above criteria, shall be select granular borrow.
7. A gravel base composed of 4" Mn/DOT Class 2 100% crushed compacted or 5" Mn/DOT Class 5 compacted shall be required as a minimum.
8. The minimum bituminous pavement shall consist of 2" compacted thickness of binder course conforming to the requirements of Mn/DOT Specification 2331, Type 31, and 1½" compacted thickness of wearing course conforming to the requirement of Mn/DOT Specification 2331, Type 41.
(b) Curb and Gutter. Concrete curbs and gutters shall be required for all streets. Concrete curbs and gutters for residential streets shall be D-412 with B-618 at all catch basins, intersections, and cul-de-sac entrance radii unless otherwise approved by the City. Collector, commercial and industrial streets shall have B-618 concrete curbs and gutters. Expansion joints shall be installed every 50 feet.
(c) Pavements Widths. Minimum pavement widths, as measured from back of curb to back of curb, shall be 32 feet for residential streets. Collector, commercial and industrial streets shall be designed to a width determined by the City Engineer.
(d) Curb Radii. The minimum curb radii to back of curb shall be as follows:
1. Intersections and cul-de-sac entrance radii shall be 20 feet.
2. Cul-de-sac radii shall be 46 feet.
3. Collector, commercial and industrial streets shall have radii as determined by the City Engineer.
(e) Grades. All centerline grades shall be at least five-tenths percent (0.5%) and shall not exceed four percent (4%) for arterial and collector streets and six percent (6%) for local streets. Vertical curves appropriate for the street shall be provided. The minimum curb grade shall be five-tenths percent (0.5%), except curbs in cul-de-sacs shall have a minimum grade of six-tenths percent (0.6%).
(f) Boulevards. Boulevard design and use shall be as follows:
1. Boulevards shall have a grade slope of 1/4" per foot for the eight feet adjacent to the back of curb. All slopes beyond this shall be 3:1 ratio, maximum.
2. All boulevards shall be sodded or seeded with mulch in accordance with Mn/DOT Specification 2575, and shall include three inches of acceptable topsoil of a turf growing medium to meet Mn/DOT Specification 3877. All disturbed areas beyond the boulevard shall also be sodded or seeded as above.
3. Street trees having a trunk diameter (measured 12 inches above the ground) of not less than 2½ inches shall be planted along all streets, where sufficient trees do not exist. These trees shall be placed at the property line. One tree per lot shall be required. This requirement will be satisfied and it is preferable if an equivalent number of trees of the same size are planted in a naturalistic way in the front yards of the adjoining lots.
4. Private utility placement shall occur under the established guidelines of the city.
(Prior Code, §§302.03, 302.04, 302.11; Am. Ord. 03-90, passed 5-29-1990.