07-11-1979 Council Agenda - Laserfiche WebLink

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January 1, 1977 ' MINNESOTA TRAFFIC ENGINEERING MANUAL V.8.3. (Continued) b. Guidelines — The determination ana implementation of speed limits on Trunk Highways Is solely the responsibility of the Department. Procedural elements of speed zone determination including the "engineering and traffic investi- gation" are discussed in Chapter 11, with further Information on signing to be found in Chapter 5. 4. Speed Zoning within Local Areas - MSA 169.14, Subd. 5 a. The taw — When local authorities believe that the existing speed limit upon any street or highway, or part thereof, within their respective jurisdictions and not a part of the trunk highway system is greater or less than is reasonable or sate under existing conditions, they may request the commissioner to authorize, upon the basis of an engineering and traffic investigation, the erection of appropriate signs designating what speed is reasonable and safe, and the commissioner may authorize the erection of appropriate signs designating a reasonable and safe speed limit thereat, which speed limit shall be effective when such signs are erected. Any speeds in excess of these speed limits shall be prima facie evidence that the speed is not reasonable or prudent and that It is unlawful; except that any speed limit within any municipality shall be a maximum limit and any speed in excess thereof shall be unlawful. Alteration of speed limits on streets and highways shall be made only upon authority of the commissioner except as provided in subdivision 5a (school zones). MSA 169.14 Subd. 5. (Note: A further exception Is provided under MSA 160.263 relative to bicycle. lanes. Both exceptions are discussed later in this chapter.) b. Guidelines — On all streets and highways other than Trunk Highways, the local authority must request authorization and investigation by the Department. Upon departmental authori- zation, the local authority is responsible for placing and maintaining the speed zone signs on roadways under its jurisdiction. 5. District Investigation The District Traffic Engineer is responsible for the surveys and data collection needed to determine speed limits on all streets and highways. The results of the District Traffic Engineer's Investigation and his recommendations shall be transmitted to and approved by the State Traffic Engineer before any speed limit may be revised. The procedures to follow in establishing appropriate speed limits are described in Chapter 11 of this Manual. 6. Sign Placement Speed limit signs must be placed at the beginning of all speed zones and al appropriate intervals through each zone. On divided highways, supplemental speed limit signs may be placed in the median. More specif is details on speed limit sign placement are provided in Chapter 5. 7. School Speed Limits - MSA 169.14, Subd. 5a a. The Law — Local authorities may establish a school speed limit within a school zone upon the basis of an engineering and traffic investigation as prescribed by the commissioner of highways. The establishment of a school speed limit on any trunk highway shall be with the consent of the commissioner of highways. Such school speed limits shall be in effect when children are present, going to or leaving school during opening or closing hours or during school recess periods. The school speed limit shall not be lower than 20 miles per hour end shall not be more than 15 miles perhourbelow the established speed limit on an affected street or highway /f the established speed limit is 40 miles per hour or greater. The school speed limit shall be effective upon the erection of appropriate signs designating the speed and indicating the beginning and end of the reduced speed zone. Any speed in excess of such posted school speed limit is unlawful. All such signs shall be erected by the local authorities on those streets and highways under their respective jurisdictions and by the commissioner of highways on trunk highways. MSA 189.14 Subd. 5a. b. Authority — MSA 169.14 Subd. 5a, quoted above, grants local authorities (city councils and county board but not school districts) the power to establish reduced speed limits in "school zones" without Department authorization. Depart- ment consent is required only If a Trunk Highway would be affected by the proposed action. Except on Trunk Highways, the placement and maintenance of any such traffic control devices Is the responsibility of the local authority. School speed zoning will not automatically reduce speeds or accidents, and therefore must be done carefully. Furthermore, the school zone limit is "part time" (in effect only when children are present, going to or leaving school during normal school hours) and must be Identified accordingly. It is therefore Important to consider alternatives which can be effective 24 hours per. day before school speed zones are implemented. Examples. of these alternatives are sidewalk construction, parking restric- tions, crossing guards, stop signs and signals, and pedestrian rerouting. c. Engineering and Traffic investigation — The required procedures for conducting the investigation are outlined In "A Guide to Establishing Speed Limits In School Zones." The local authority shall complete an engineering and traffic investigation as prescribed by the Department before a school speed zone can be established. This Investigation shall include: (1) a school route plan and (2) a school zone hazard evaluation. 8. Minimum Speed Limits - MSA 169.14, Subd. 8 a. The Law — Where the commissioner determines upon the basis of an engineering and traffic investigation that a speed at least as great as, or in excess of, a specified and determined minimum is necessary to the reasonable and safe use of any trunk highway or portion thereof, he may erect appropriate signs specifying the minimum speed on such highway or portion thereof. The minimum speed shall be effective when Such signs ere erected. 'Any speeds less than the posted minimum speeds shall be prima facie evidence that the speed is not reasonable or prudent and that it is unlawful. MSA 169.14 Subd. 8. b. Guidelines — The Department has the authority to establish minimum, as well as maximum, speed limits on Trunk Highways. The determination of minimum speed limits is usually based on engineering judgment, taking Into consideration the fact that safety decreases as speed differ- entials Increase. As a general rule, speed differentials greater than 15 -20 miles per hour are not desirable. An engineering and traffic investigation must precede the determination of �( / L) 3 zip 2 -12 •