POLICY FOR THE ESTABLISHMENT AND POSTING OF SPEED LIMITS ON COUNTY AND TOWNSHIP HIGHWAYS WITHIN MCHENRY COUNTY, ILLINOIS MCHENRY COUNTY DIVISION OF TRANSPORTATION 16111 NELSON ROAD WOODSTOCK, IL 60098 Adopted by the McHenry County Board: November 19, 1996 Revised Policy Adopted by the McHenry County Board: December 15, 1998 Revised Policy Adopted by the McHenry County Board: June 7, 2011 ** See Appendix A for revisions for June 7, 2011 ** 1
I. INTRODUCTION Section 11-601, of the Illinois Vehicle Code specifies statutory speed limits on streets, alleys, and highways in rural and urban areas by various classifications of vehicles. Provisions for the altering of these statutory speed limits by the local authority having maintenance jurisdiction or responsibility is defined in the Illinois Vehicle Code Section 11-604, subject to certain restrictions. Specific sections of the law state that any alterations must be based upon an engineering and traffic investigation and appropriate signs giving notice of the altered limit must be erected. Altered speed limits established on the basis of opinions of either public officials or private individuals have no legal authority. Speed limits, both statutory and altered, are absolute in character, and no motorist may legally exceed such limits at any time, regardless of conditions. Therefore, an altered speed limit shall reflect the optimum, rather than the adverse, driving condition, as drivers are subject to citation even though traveling at a speed lower than the posted limit if they are driving at a speed that is greater than is reasonable and proper with regard to traffic conditions and the use of the highway, or endangers the safety of any personal property. Altered speed limits establish a restraint upon the freedom of the driver to choose a speed at which the driver desires to travel and therefore should be imposed only to the extent that their use will facilitate traffic flow by reducing turbulence in the traffic stream. Driver acceptance is a prerequisite to effective enforcement. If the regulations are imposed only where they are needed and necessary, the driver will more readily accept the need for them. Conversely, an improper or unreasonably low speed limit posting is often violated by the majority of the motoring public, making enforcement of the speed limit completely impracticable, with the resultant operating speeds higher than would exist with a proper and reasonable speed posting. The installation of all signs regulating speed is detailed in the Illinois Manual on Uniform Traffic Control Devices for Streets and Highways. 2
II. STATUTORY SPEED LIMITS In the State of Illinois the following speed limits have been established by statute. Maximum speed limits for the areas described are legally enforceable with or without posted signs. 1. Outside urban districts All vehicles 55 mph 2. In urban districts Streets and Highways 30 mph Alleys 15 mph An urban district is defined in the Illinois Vehicle Code as The Territory contiguous to and including any street which is built up with structures devoted to business, industry or dwelling houses situated at intervals of less than 100 feet for a distance of a quarter of a mile or more. The structures referred to in the definition should include only those that have direct access to the highway. Structures on both sides of the highway should be counted together in determining the interval. 3
III. LIMITS OF AUTHORITY FOR ALTERATION OF STATUTORY LIMITS The County Engineer may submit to the Illinois Department of Transportation for approval, a county policy for establishing altered speed zones on township and county highways based upon engineering and traffic investigations. The County Board of each county upon any county, or township road except those under the jurisdiction of the Illinois Department of Transportation or the Illinois Toll Highway Authority, may establish by ordinance absolute maximum speed limits as follows. 1. In urban districts not less than 20 mph not more than 55 mph 2. Outside urban districts not less than 35 mph not more than 55 mph Not more than six alterations shall be made per mile, and the difference in limit between adjacent altered speed zones shall not be more than 10 miles per hour. Minimum speed limits may be posted at any location where it has been determined that the slow vehicles are impeding the traffic flow. Upon passage of a speed zone ordinance by the County Board, the speed limit becomes effective after erection of the appropriate signs. 4
IV. CRITERIA FOR SELECTING SPEED LIMITS IN ALTERED SPEED ZONES BASIC INVESTIGATION The prevailing speed of free flowing traffic has been recognized by most transportation agencies as the basic parameter for use in establishing speed limits either higher or lower than the statutory speed limits set by Article 11-601 of the Illinois Vehicle Code. Prevailing speed shall be determined by use of two separate sets of data, which are: 1. The eighty-fifth (85 th ) percentile speed. 2. Upper limit of the consecutive 10 miles per hour that have the most observations, also known as the upper limit of the 10 mph pace. The prevailing speed shall be determined by computing the average of the measured values for the criteria listed above. Based on the assumption that a majority of motorists will drive at a speed which they judge to be safe and reasonable, the selected speed limit in 5 mph increments should not differ from the established prevailing speed by more than 3.0 mph unless justified by supplementary investigations. OPTIONAL SUPPLEMENTARY INVESTIGATIONS The altered speed limit may differ from the established prevailing speed by more than 3.0 mph when justified by further investigation. Such investigation shall include the study of the following conditions: 1. Accident rate 2. Land use of the territory contiguous to the County or Township highway. 3. Pedestrians 4. Parking 5
A. County Highways 1. Accidents The number of accidents per mile during the past two years in the zone being studied shall be divided by the average number of accidents on all similar County highways (similar geometry, traffic control, and traffic volumes) over the same time with the following reductions applying: (# of Accidents per Mile in Zone {past 2 years})/(average # of Accidents per mile on similar county roads) Allowed % Reduction of Prevailing Speed 0.0 1.0 0 1.1 1.9 5 2.0 or greater 10 Only accidents, which are required to be reported under Section 11-406 of the Illinois Vehicle Code, will be considered in computing accident rates. 2. Land Use Reductions to the prevailing speed because of the land use abutting the County Highway are as follows: Number of Access Points Per Mile % of Non-residential Access Points Less than 50 more than 51 0-20 0 3 21-40 3 6 41-60 6 9 Greater than 61 9 12 Each minor intersection shall count as 5 non-residential access points; each major intersection shall count as 10 non-residential access points. Percent of non-residential access points is equal to the number of nonresidential drives, minor and major intersections per mile divided by the equivalent total access points per mile. 3. Pedestrians When it is anticipated that pedestrians will be crossing within the zone being studied and the point of crossing is not protected by some other form of speed control or intersection control device, a 5 percent reduction in the prevailing speed is allowed. this reduction may be applied only once in the establishment of any particular zone. 4. Parking 6
Where parking is permitted adjacent to the traffic lanes, the prevailing speed may be reduced by 5 percent. This reduction may be applied only once in the establishment of any particular zone. 5. General The total reduction in prevailing speed shall be the sum of the reductions due to accidents, land use, pedestrians, and parking. The difference between existing posted speed and proposed posted speed shall not be greater than 10 M.P.H. B. Township Highways 1. Accidents The number of accidents per mile during the past two years in the zone being studied shall be divided by the average number of accidents on all similar township roads (note: due to lack of township accident data, similar County highway accident data may be used in lieu of township data providing the County highways used are similar in characteristics to the township roads being studied) over the same time with the following reductions applying: (# of Accidents per Mile in Zone {past 2 years})/(average # of Accidents per mile on similar Township (County) roads) Allowed % Reduction of Prevailing Speed 0.0 1.0 0 1.1 1.9 5 2.0 or greater 10 Only accidents, which are required to be reported under Section 11-406 of the Illinois Vehicle Code, will be considered in computing accident rates. 7
2. Land Use Reductions to the prevailing speed because of the land use abutting the Township Highway are as follows: Number of Access Points Per Mile % of Non-residential Access Points Less than 50 more than 51 0-20 0 3 21-40 3 6 41-60 6 9 Greater than 61 9 12 Each minor intersection shall count as non-residential access points; each major intersection shall count as 10 non-residential access points. Percent of non-residential access points is equal to the number of nonresidential drives, minor and major intersections per mile divided by the equivalent total access points per mile. Subdivisions: A subdivision is a group of dwellings, exclusively residential in purpose, along a street system that serves only residents of the subdivision. An altered speed limit of 25 mph may be permitted by the County Engineer on the streets of subdivisions. 3. Pedestrians When it is anticipated that pedestrians will be crossing within the zone being studied and the point of crossing is not protected by some other form of speed control or intersection control device, a 5 percent reduction in the prevailing speed is allowed. This reduction may be applied only once in the establishment of any particular zone. 4. Parking Where parking is permitted adjacent to the traffic lanes, the prevailing speed may be reduced by 5 percent. This reduction may be applied only once in the establishment of any particular zone. 5. General The total reduction in prevailing speed shall be the sum of the reductions due to accidents, land use, pedestrians, and parking. The difference between existing posted speed and proposed posted speed shall not be greater than 10 M.P.H. V. PROCEDURES FOR OBTAINING PREVAILING SPEED DATA 8
Spot speed studies, normally made with an electric speed-measuring device (i.e. radar speed meter, traffic counter/classifier) are to be used on county and township highways. The data received from these devices is to be analyzed to determine the 85th percentile speed and the upper limit of the 10 mile per hour pace. The 85th percentile speed is defined as the speed at which 85 percent of the vehicles are traveling at or below. The traffic counter/classifier (if used) should collect at least 24 hours worth of data per direction of traffic. Spot speed studies should be made as close to the center of the proposed zone as is practical. If the zone is in excess of one mile in length studies should be made every mile. If the difference in prevailing speed between the two adjacent locations is less than 5 mph, the lower value should be used. If the difference in prevailing speed is over 5 mph, consideration should be given to designating two separating zones. Care must be exercised to be sure that the data is collected in such a manner and at such times that it is a true indication of normal conditions. Such conditions are assumed to prevail under clear weather conditions with dry pavement, following the morning peak traffic hours (7:00 A.M. - 9:00 A.M.) and prior to the evening peak traffic hours (3:00 P.M. - 6:00 P.M.) on any weekday (Monday through Friday) except holidays, and weekends (Saturday and Sunday). The traffic study shall not be taken the day prior to a holiday or the day after a holiday. Observations should not be made immediately following a spectacular accident or during a period of greater than normal police enforcement. Every effort should be made to conceal the fact that speeds are being recorded. Speeds should be observed for a total of 100 passenger cars and pickup trucks in each direction (lane). Speed of trucks over 4 tons shall not be included in the data for determining an altered limit. On low-volume roads where it would be difficult to obtain a sample of 100 vehicles in each direction, the study may be terminated after a study period of three hours. 9
VI. SUPPLEMENTAL POLICIES The following additional policies shall be observed in establishing and posting speed zones: Normally, isolated curves and turns, areas of restricted sight distance, no passing zones, etc., will not be considered as areas for speed zones. Advisory speed signs may be used in connection with the appropriate warning signs at such locations and such condition shall not be considered as influencing a lower limit for the entire zone. Except on divided highways, different speeds for traffic in opposite directions shall not be posted. A speed zone shall begin at the point or as near in advance of the point as possible where such speed zone is warranted and shall end at the point or as near to the point as possible where the zone is not warranted. A change within a zone shall be as near to the point as possible where the change is to take place. Minimum speed limits, when used, shall provide for an allowable speed range of not less than 10 mph or more than 15 mph for any class of vehicle. No minimum speed of less than 30 mph shall be used. No sign in the speed limit (R2) series shall be mounted on the same post as another sign, except that the basic speed limit sign (R2-1) may be mounted below the town name sign (I1-I100 or I1-I101). 10
VII. POSTING OF ALTERED SPEED LIMITS The SPEED ZONE AHEAD sign (R2-5), together with a corresponding advisory speed plate (R2-I101), shall be erected in advance of any speed zone that is greater than 10 mph under the passenger car limit in a preceding statutory limit. The SPEED ZONE AHEAD sign shall be placed approximately 500-600 feet in advance of all altered speed zones in accordance with Section 2B-14 of the Illinois Manual on Uniform Traffic Control Devices for Streets and Highways and shall always be followed by a basic speed limit sign (R2-1) erected at the beginning of the zone where the altered speed limit applies. On divided highways, signs shall be posted on both sides of the highway for all signs described above. Additional speed limit signs, as described in E below, in the same zone need not be posted on both sides of the road. The difference in the speed limit from one altered speed zone to an adjacent altered speed zone shall not be more than 10 mph. At any location where one limit is to apply to all vehicles, including trucks with gross weight over 4 tons, only the basic speed limit sign (R2-1) will be installed. Speed limit signs for altered zones shall be erected: 1. At the beginning of each zone where the speed limit is altered. 2. At the point of change from one zone to another. 3. At additional locations within the zone where it is necessary to remind the motorist of the limit that is applicable. Signs shall not be erected until the speed limits are approved and are officially authorized. The distance between basic speed limit sign installations in altered speed zones should be as follows: Speed Limit mph Minimum Distance Maximum Distance 30 or less 660 feet or 2 blocks 1,320 feet or 4 blocks 35 or 40 990 feet or 3 blocks 1,980 feet or 6 blocks 45 or 50 1,320 feet or 4 blocks 2,640 feet or 8 blocks **The recommended distances between speed signs do not apply to the posting of statutory limits. The size of the speed limit signs shall be a minimum of 24 x 30 and shall correspond to the Illinois Manual on Uniform Traffic Control Devices. Except where stated elsewhere in this policy, the Illinois Manual on Uniform Traffic Control Devices shall govern the posting of all speed zones on County Highways. VIII. SCHOOL SPEED LIMITS 11
Section 11-605 of the Illinois Vehicle Code permits the establishment of a 20 mph speed limit in school zones. The following policies shall govern the establishment of school speed zones: An engineering and traffic investigation shall be conducted at each individual location to determine whether or not a school speed limit is warranted. Such factors as existing traffic control devices, existing traffic control measures, the type, character, and volume of vehicular traffic, and the age, character, and number of school children shall be considered. Based on these factors, a 20 mph speed zone may be considered as warranted, provided the regulation (1) will appear to bring about the desired result of increased safety for the school children (2) will appear to motorists as being a reasonable regulation, and (3) will not appear to be an arrangement for a speed trap. School speed zones shall be limited to those locations where grade, middle, or junior high school buildings or grounds devoted primarily to normal school day activities are adjacent to the highway or where groups of children cross the highway en route to and from a school not adjacent to the highway. Areas devoted primarily to athletic or other extracurricular activities shall not be zoned. School speed limits should not be posted when one of the following conditions exists: 1. Devices protect school children, such as stop signs or traffic signals, where motorists are required to come to a complete stop. An exception may be made when the zone serves to protect children walking on or immediately adjacent to the roadway in the school areas. 2. The school or school grounds are completely isolated from the highway by means of a fence or other barrier, and no access to the highway is provided. 3. An underpass or overpass structure has been provided. 4. Entrance to and exit from the school grounds are by school bus or other vehicle only. The 20-mph school speed zone is in effect only on school days when children are present. At all other times, the posted limit through the entire area applies. The following signs are used to designate school speed zones: 1. When the speed limit in the area is greater than 30 mph, a SCHOOL SPEED ZONE AHEAD sign shall be used in advance of the school zone. 2. At the beginning of the school speed zone, the SCHOOL SPEED LIMIT 20 ON SCHOOL DAYS WHEN CHILDREN ARE PRESENT sign shall be placed. 3. In unincorporated areas that have school speed limits, passing is prohibited during the times the school speed limit is in effect. At these locations, a 12
combination speed limit and do not pass sign is used in lieu of the first S4- I100 sign in each direction. Required Signs: 1. The school speed limit sign shall have the word SCHOOL in black letters on a yellow background with the remainder of the sign having black letters on white backgrounds. 2. At the end of the school speed zone, the speed limit for the following section of highway shall be posted with the appropriate standard speed limit sign. 3. Figure 1 shows typical signing for schools having a school speed zone. 13
IX. LOCATION OF STATUTORY SPEED LIMIT SIGNS ON COUNTY HIGHWAY OUTSIDE URBAN DISTRICTS. The appropriate R2-1 signs shall be erected in the following locations: 1. Points where county maintenance begins. 2. At the end of all reduced speed zones. 3. At major intersections along the County Highway. 14
Proposed Revisions June 7, 2011 Appendix A: CONSTRUCTION AND MAINTENANCE WORK ZONE SPEED LIMITS ON COUNTY AND TOWNSHIP HIGHWAYS Introduction During the period of road construction there a numerous factors, which could contribute to make existing speed limits greater than what is reasonable safe with respect to conditions found on the County Highway during construction. On those County Highways, which have a speed limit that is greater than is reasonable with respect to the ongoing construction, the Local Agency may delegate to its Superintendent of Highways the authority to set and post a work zone speed limit as established in Section 11-605.2 of the Illinois Vehicle Code. After completion of an engineering and traffic investigation the existing speed limit may be lowered up to 20 mph to a minimum work zone speed limit of 35 mph for the duration of the construction project. This temporary Work Zone Speed Limit shall be removed if the construction project is suspended for over 30 days and roadway conditions return to normal. General Criteria The engineering and traffic investigation that may be used on County Highways, should meet the following criteria: A. The existing speed limit within the area of construction is 45 mph to 55 mph. Work zone speed limits shall be lowered by increments of 10 mph or more from the existing speed limit. B. The length of the construction project will be over 10 working days. C. The type of construction activities will mean that lowering the existing speed limit will enhance worker safety and motorist safety. Investigation The existing speed limit may be reduced to 35 mph when justified by further investigation of the conditions listed below. Each condition that is met allows a percentage of reduction. A total of 15% or more must be obtained in order to justify a change. This procedure shall not be used to establish a work zone speed limit below 35 mph. A. Taper Length: The taper length shown on the plans or set up in the field cannot meet the minimum taper length of the existing posted speed limit as 15
described in the Illinois Manual on Uniform Traffic Control Devices, due to conditions that are beyond the control of the engineer. 5% reduction B. Pavement Width of Traffic Lanes: If the existing pavement width of the lanes of traffic is being reduced due to construction to 11 feet or less. 5% reduction C. Lane Reductions: During the period of construction, traffic lanes will be closed in order to perform construction activities on the following roads. Lanes closed multi-lane road (4 or more lanes), 5% reduction Lanes closed two or three lane road, 10% reduction D. Flaggers Present: During construction if the use of flagging personnel will be needed to control traffic in accordance with the traffic control plan or highway standards. 5% reduction E. Workers Present in/or Adjacent to Traffic Lanes: If during construction, workers will be present in the traffic lanes, the closed traffic lane, or within 10 feet of the traffic lane. 5% reduction F. Shoulders: If during construction the work requires the removal of the roadway shoulders for a period of 4 or more calendar days. 5% reduction The work zone speed limit shall be in effect from the start of the construction activities until the end of the construction activities except for work suspensions of over 30 days where roadway conditions return to normal. Posting Construction or maintenance zone speed limit signs shall: A. Be of a design approved by the Illinois Department of Transportation, B. Give proper warning that a construction or maintenance speed zone is being approached, C. Indicated the maximum speed limit in effect, and D. State the amount of the minimum fine for a violation as established by 625 ILCS 5/11-605.1. A record shall be maintained by the Division of Transportation naming each location, the reduced speed limit set and posted for the construction or maintenance zone and dates during which the reduced speed limit was in effect; and The affected police enforcement jurisdictions shall be notified of the changes in the posted speed limits so that they may be properly enforced. 16