Minnesota
Manual on Uniform Traffic Control Devices
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INDEX - Speed limit Sign Information ONLY Regulatory Speed Limit Signs (Chapter 2B -10  through  2B -14.2) Advisory Speed Limit Signs (Chapter 2C - 35) School Speed Limit Signs (Chapter 7B - 12) Work Zone Advisory Speed Limit Signs (Chapter 6F - 47 and 6I - 1)     Work Zone Speed Limit Signs .... refer to the "Guide to Establishing Speed Limits in Highway Workzones" For more information on Speed Limits, visit the Mn/DOT OTE/ITS Speed Limit Resources Site Regulatory Speed Limit Signs Click here to Return to MnMUTCD Speed Limit Sign Information Index 2B-10 Speed Limit Sign (R2-1) The Speed Limit sign shall display the limit established by law, or by regulation, after an engineering and traffic investigation has been made in accordance with established traffic engineering practices. The speed limits shown shall be in multiples of 5 miles per hour. Minnesota Statute (Section) 169.14) states that: 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 safe 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 a reasonable and safe speed limit thereat, which speed limit shall be effective when such signs are erected. In order to determine the proper numerical value for a speed zone on the basis of an engineering and traffic investigation the following factors should be considered: 1. Road surface characteristics, shoulder condition, grade, alignment and sight distance. 2. The 85-percentile speed and pace speed. 3. Roadside development and culture, and roadside friction. 4. Safe speed for curves or hazardous locations within the zone. 5. Parking practices and pedestrian activity. 6. Reported accident experience for a recent 12-month period. Two types of speed limit signs may be used: One to designate passenger car speeds including any nighttime information or minimum speed limit that might apply, and the other to show any special speed limits for buses and trucks. No more than three speed limits should be displayed on any one speed limit sign or assembly. Where a special speed limit applies to trucks or other vehicles, the legend TRUCKS 40, or such similar message as is appropriate, shall be shown below the standard message or on a separate plate (R2-2). When used independently, the Truck Speed sign should carry a reference to SPEED or MPH. R2-1 24" x 30" R2-2 24" x 24" Minimum speeds shall be displayed only in combination with the posted speed limit (sec. 2B-12). Advisory Speed signs are treated under section 2C-35. The standard Speed Limit sign shall be 24x30 inches. On express-ways the sign should be at least 36x48 inches, with 48x60 inches prescribed for use on freeways. 2B-10.1 Bridge Speed Limit Sign (R2-X5) The BRIDGE SPEED LIMIT sign shall be used and installed as stated in the following State Statute. Minnesota Statutes (Section 169.16) state that: 1. When it has been determined by the Commissioner of Transportation that it is necessary to limit the speed of vehicles on a bridge or other elevated structure constituting part of a highway to the maximum speed which can be maintained with safety on such bridge or structure, 2. Suitable signs stating such maximum speed shall be erected and maintained at a distance of 100 feet before each end of the structure. A Reduced Speed Ahead sign (R2-5a) should be used in advance of the bridge speed limit sign. R2-X5 24" x 36" 2B-10.2 School Speed Limit Sign (R2-6) The School Speed Limit sign shall be used to indicate the speed limit where a reduced speed zone for a school area has been established (in accordance with law, after an engineering and traffic investigation) or when a speed limit is specified for such areas by statute. Further information on the use a of school speed limit signs can be found in Section 7B-12. 2B-11 Night Speed Sign (R2-3) Where different speed limits are prescribed for day and night, both the limits shall be posted. This may be done in either of two ways: 1. Immediately below the Standard Speed Limit sign (R2-1) or combined with it, a Night Speed sign (R2-3) carrying the legend NIGHT 45 (or other suitable numerical limit) may be erected. In this case the numerals in the Night Speed sign and only the words SPEED LIMIT in the standard sign, should be reflectorized. As a special but logical exception to the general color scheme, the Night Speed sign should have its legend in white upon a black background. 2. A changeable message sign may be used, so that only the appropriate regulation is visible at a given time. The sign may have interchangeable panels, or reflectorization of the nighttime speed superimposed over the unreflectorized numerals of the daytime speed, to permit only the nighttime speed to become legible in the beam of motor-vehicle headlamps at night. 2B-12 Minimum Speed Sign (R2-4) Where an engineering and traffic investigation shows that slow speeds on a highway consistently impede the normal and reasonable movement of traffic, signs may be used to post a minimum legal speed. Driving slower than the minimum limit is illegal except when necessary for safe operation or in compliance with the law. The minimum speed shall be displayed only in combination with the posted speed limit, and if desired, these two signs may be combined (R2-4a). The Minimum Speed sign shall have a standard, and minimum, size of 24 by 30 inches. R2-3 24" x 24" R2-4 24" x 30" R2-4a 24" x 48" 2B-13 Location of Speed Limit Sign Speed Limit signs, indicating speed limits for which posting is required by law, shall be located at the points of change from one speed limit to another. These signs shall not be erected until the speed limits are approved and officially authorized. At the end of the section to which a speed limit applies, a Speed Limit sign showing the next speed limit shall be erected. Additional signs shall be installed beyond major intersections and at other locations where it is necessary to remind motorists of the limit that is applicable. In school areas, the END SCHOOL ZONE sign may be used as an alternate to the Speed Limit Sign. The Speed Zone Ahead sign (sec. 2B-14) may be used to give advance notice of a speed zone with a lower limit. In rural districts on U.S. and other State numbered routes, Speed Limit signs indicating the statutory speed limits shall be erected at entrances to the State and at boundaries of metropolitan areas. A special oversize sign is often desirable at these locations. 2B-14 Sign for Reduced Speed Ahead (R2-5) This sign should be used in rural areas to inform the motorist of a reduced speed zone when an advance notice is needed to comply with the speed limit posted ahead. The sign is not ordinarily needed in urban areas where speeds are relatively low. This sign shall always be followed by a Speed Limit sign erected at the beginning of the zone where the altered speed limit applies. This sign shall have a standard size of 24 by 30 inches. It shall, however, be of the same size as the Speed Limit sign at the beginning of the speed zone, shall be erected in the same manner, and shall display one of the three illustrated legends. R2-5a 24" x 30" R2-5b 24" x 30" R2-5c 24" x 30" 2B-14.1 End Speed Zone Sign (R2-6) There are many secondary roads, county, township and municipal, which have been speed zoned in and on the fringes of urban districts (as defined in Minn. Statutes 169.01 DEFINITIONS, Subd. 59) where the rural speed limit remains at that provided in the statutes and continuous speed zoning has not been warranted. In many instances the posting of the statutory speed limit to terminate the reduced speed zone would be inappropriate because the statutory limit would be misleading and encourage drivers to travel too fast for conditions. Sound engineering judgement would dictate that no numerical value should be posted and that the basic rule (Minn. Statutes 169.14 SPEED RESTRICTIONS, Subd. 1) should apply. In order to provide for the termination of the reduced speed zone without posting another numerical speed, the END (30) MILE SPEED sign (R2-6) may be used. R2-6 24" x 30" R2-6a 24" x 30" 2B-14.2 End Work Speed Zone (R2-6A) Certain street and highway construction and maintenance operations may justify erection of regulatory signs with a recommended speed as determined by the appropriate road authority. It is necessary to install a regulatory sign to inform the motorists of the end of the regulatory speed zone. The sign shall be installed on its own structure at the end of the zone in accordance with standard signing practices for construction zone signs. Advisory Speed Limit Signs Click here to Return to MnMUTCD Speed Limit Sign Information Index 2C-35 Advisory Speed Plate (W13-1) The advisory speed plate is intended for use to supplement warning signs. The standard size of the Advisory Speed plate shall be 18x18 inches. Advisory Speed plates used with 36-inch and larger warning signs shall be 24x24 inches. The plate shall carry the message (35) MPH in black on yellow background except for construction and maintenance signs (Sec. 6F-47). The speed shown shall be a multiple of 5 miles per hour. The plate may be used in conjunction with any standard yellow warning sign to indicate the maximum recommended speed around a curve or through a hazardous location. It shall not be used in conjunction with any sign other than a warning sign, nor shall it be used alone. When used, it shall be mounted on the same assembly and normally below the standard warning sign (fig. 2-1, page 2A-14). Except in emergencies, or at construction or maintenance sites, where the situation calling for an advisory speed is temporary, an Advisory Speed plate shall not be erected until the recommended speed has been determined by accepted traffic engineering procedures. Because changes in surface characteristics, sight distance, etc., may alter the recommended speed, each location should be periodically checked and the speed plate corrected if necessary. W13-1 18" x 18" 24" x 24" School Speed Limit Signs Click here to Return to MnMUTCD Speed Limit Sign Information Index 7B-12 School Speed Limit Signs (S4-1, S4-2, S4-3, S4-4) The School Speed Limit sign shall be used to indicate the speed limit where a reduced speed zone for a school area has been established (in accordance with law, after an engineering and traffic investigation) or when a speed limit is specified for such areas by statute. The sign shall be either a fixed-message sign assembly or a variable display type sign. The fixed message sign assembly shall consist of a top panel (S4-3), 24" x 8" (the legend SCHOOL in black on a yellow background), a Speed Limit sign (R2), 24" x 30", and a bottom panel (S4-1) indicating the specific periods of the day and/or days of the week, when the special school speed limit applies. The bottom panel shall be 24" x 10" (or larger if needed) and shall have a black legend on a white background. Alternate legends such as WHEN CHILDREN ARE PRESENT (S4-2) may be used if permitted by law. The numerical speed limit displayed on the sign shall be the limit established by law. Variable display signs may be used to indicate the special school speed limit. These signs may use blank-out messages or other methods to display the school speed limit only during the periods it applies. A Speed Limit Sign Beacon (sec. 7D-24) may also be used, with a WHEN FLASHING sign (S4-4), to identify the periods the school speed limit is in force. The lenses of the Speed Limit Sign Beacon may be positioned within the face of the School Speed Limit sign (S5-1). Because of special features, it may not always be practical to make variable display signs conform in all respects to the accepted standards. However, during the periods the school speed limit is in force, their basic shape, message, legend layout, and colors should conform to the standard for the fixed message sign, except that if the sign is internally illuminated, it may have a white legend on a black background. S4-1 24" x 10" S4-2 24" x 10" S4-3 24" x 8" S4-4 24" x 10" Work Zone Advisory Speed Limit Signs Click here to Return to MnMUTCD Speed Limit Sign Information Index 6F-47 Advisory Speed Plaque (W13–1) In combination with a warning sign, an advisory speed plaque may be used to indicate a recommended safe speed through the temporary traffic control zone. When used with orange temporary traffic control zone signs, this plaque shall have a black legend and border on an orange background. It shall not be used with any sign other than a warning sign, nor shall it be used alone. The sign shall be at least 24 inches square when used with a sign 36 inches square or larger. Except in emergencies, an advisory speed plaque (W13–1) shall not be installed until the recommended speed is determined by the highway authority. W13-1 24" x 24" 6I-1 Advisory Speeds The purpose of advisory speeds is to identify safe speeds for specific hazards. Warning signs with advisory speed plaques warn drivers of a particular hazard or a potentially hazardous condition and indicate the safe speed at which to undertake the hazard. Examples of situations where an advisory speed plaque may be used are bypasses to indicate the curve, low and no shoulder situations and where there is reduced visibility due to work activities, environmental factors or geometrics. Advisory speed plaques may be posted any time a hazard is present; an authorization from the Commissioner of Transportation is not necessary. However, traffic engineering personnel should be consulted as to the reasonable speed to be posted. In some situations such as sharp curves, there are recommended maximum speeds established for a certain degree of curve. In situations other than horizontal curves, the proper advisory speed is determined by experience and good engineering judgement. An advisory speed is posted by installing an Advisory Speed Plaque, (W13-1) under the appropriate advance warning sign(s). Advisory speed plaques shall not be posted alone. Once installed the advisory speed should be tested by driving through the hazard at the posted advisory speed. Care should be taken when posting an advisory speed plaque that it is not placed near a regulatory speed sign so that the motorist may confuse the two speeds. Inplace speed limits shall be reviewed to ensure that the advisory speed is not higher than the regulatory speed. The advisory speed plaque should be the same color as the warning sign and be at least 24 inches square in size.