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HomeMy WebLinkAbout2013-01-22 - AGENDA REPORTS - MULTIWAY STOP POLICY (2)Agenda Item: 9 CITY OF SANTA CLARITA AGENDA REPORT h NEW BUSINESS City Manager Approval: ,J�-- Item to be presented by: Andrew i DATE: January 22, 2013 SUBJECT: CITY POLICY ON MULTIWAY STOP CONTROL AT RESIDENTIAL INTERSECTIONS DEPARTMENT: Public Works RECOMMENDED ACTION City Council receive report regarding the City's policy on installation of multiway stop control at residential intersections and direct staff to continue using existing policy. BACKGROUND At the December 11, 2012, City Council meeting, Councilmember Boydston requested an item be agendized for City Council consideration to evaluate the City's policy on installation of multiway stop control at residential intersections. Guidance on the installation of multiway stop control is provided by the California edition of the Manual on Uniform Traffic Control Devices (MUTCD), published by the California Department of Transportation (Caltrans). The California MUTCD contains thresholds or warrants used to determine when it is appropriate to install multiway stop control at an intersection. State law also allows local jurisdictions to adopt their own warrants for multiway stop control, as long as they are not more restrictive than the warrants in the California MUTCD. In 2003 the City Council adopted its own rules and regulations to modify the Caltrans warrants for installation of multiway stop control in residential areas to reflect lower volume traffic conditions typical of many neighborhood residential streets. The City's modified warrants were also developed to address areas of high pedestrian and youth activity, such as around elementary schools and parks. The City's policy for multiway stop control at residential intersections was developed based on a review of other cities that have also modified warrants, including the cities Continued To: 2 • 1 a -13 of Pasadena and Los Angeles. In addition, three years (2001-2003) of multiway stop control requests were reviewed to determine the impact of adopting modified warrants. As indicated in the table below, the City's warrants are 60 percent of the Caltrans warrants. These thresholds were developed in an effort to balance the traffic -related concerns of residential communities with the need for an efficient street system. Higher thresholds would limit the City's ability to install multiway stop control when a real need exists. Lower thresholds would cause a proliferation of multiway stop controlled intersections throughout the City and decrease the motoring public's respect for stop signs. The City and Caltrans warrants for multiway stop control are compared in the table below. Warrant city I CA MUTCD Minimum Volumes (all approaches) 300 per hour for 4 hours 500 per hour for 8 hours Minimum Volumes (minor street approach) 120 per hour for 4 hours 200 per hour for 8 hours Collision History 3 reported in 12 months 5 reported in 12 months The California MUTCD also allows a reduction in the minimum vehicular volume warrant by 30 percent, if the 85th percentile approach speed of the major roadway exceeds 40 mph. This is generally not applicable to residential street intersections, since the speeds on residential streets rarely exceed 40 mph. Multiway stop control should be installed to regulate traffic flow and improve safety, not to reduce speeding. Their main purpose is to provide right-of-way control at intersections and reduce the number of certain types of accidents. The California MUTCD states, "YIELD or STOP signs should not be used for speed control. " The relevant page of the California MUTCD is attached. In addition, the California MUTCD clearly states multiway stop control can be useful as a safety measure at an intersection if certain traffic conditions exist, such as the minimum volume and collision thresholds in the table above. Safety concerns associated with multiway stop control includes pedestrians, bicyclists, and all road users expecting other road users to stop. Multiway stop control should be used where the volume of traffic on the intersecting roads is approximately equal. The relevant page of the California MUTCD is attached. California Government Code section 830.6 contains a grant of immunity to cities and municipal officers against suits brought based on the plan or design of a public improvement where the allegation is that the public improvement is dangerous. The immunity is based on the subject improvement being constructed in accordance with standards approved by the legislative body. Cases interpreting the design immunity statute require that the City adopt standards based upon substantial evidence of the design's reasonableness. As stated above, in 2003 the City adopted a modified version of the MUTCD as its standard for 2 installation of multiway stop control at residential intersections. That modified standard was based upon a review of other cities that have also adopted modified warrants and the past three years of requests for multiway stop control within the City. If the City were to install traffic control devices not meeting its own standards, it would not be able to avail itself of the statutory design immunity. Any modification of the City's standard would require additional engineering work to generate the substantial evidence of reasonableness required to obtain statutory design immunity. Specific issues concerning the effectiveness of warranted and unwarranted multiway stop control are summarized in the table below. Issue Warranted Unwarranted Higher speeds few hundred feet Higher speeds few hundred feet Speeding from multiway stop control from multiway stop control location location Low rate of vehicle violation High rate of vehicle violation can Accidents results in fewer vehicle collisions cause increase in number of vehicle collisions. Low rate of violation requires only Difficult to enforce without Enforcement standard enforcement higher than typical police presence Low rate of vehicle violation High rate of vehicle violation can Pedestrians results in fewer pedestrian cause increase in number of collisions pedestrian collisions Increase fuel consumption, Increase fuel consumption, Cost increased delay and travel time, increased delay and travel time, increased enforcement increased enforcement Increase in vehicle noise due to Increase in vehicle noise due to Noise braking and acceleration braking and acceleration Increase in vehicle emissions due Increase in vehicle emissions due Emission to braking and acceleration to braking and acceleration Several studies have confirmed unwarranted multiway stop control installations do not effectively control speeding and may be ignored by motorists. For example, a study in Boulder, Colorado found 76 percent of motorists rolled through unwarranted locations, and six percent did not even slow down. A study in Troy, Michigan found the compliance rate at unwarranted locations was less than twenty percent. In addition, compliance decreased even further over a period of ten years. This creates a dangerous situation for pedestrians and other motorists and is difficult to enforce without regular police presence. The attached articles summarize the results of some of these studies. 3 A survey of the cities of Burbank, Glendale, Irvine, Lancaster, Oxnard, Palmdale, Simi Valley, Thousand Oaks, and Ventura indicates they all use the warrants contained in the California MUTCD for installation of multiway stop control. None of them have adopted their own policy for installation of multiway stop control at residential intersections, and therefore, have decided to significantly limit the use of multiway stop control in residential neighborhoods. Over the past two years, the City has evaluated 28 intersections throughout the City for multiway stop control. Six of these locations have met the criteria and have had multiway stop control installed. Five of these six locations are adjacent to or near school sites. ALTERNATIVE ACTIONS Direct staff to return with a modified policy for installation of multiway stop control at residential intersections. FISCAL IMPACT No impact if existing policy for installation of multiway stop control at residential intersections remains unchanged. If the existing policy is modified to provide lower thresholds for installation of multiway stop control at residential intersections, it is anticipated there will be an increase in the number of stop signs installed by the City annually and a corresponding increase in cost. ATTACHMENTS California MUTCD 2012 Edition, Part 2 — Signs, Page 135 California MUTCD 2012 Edition, Part 2 — Signs, Page 137 Traffic Calming Do's and Don'ts — ITE 1994 Compendium of Technical Papers Responding to Citizen Requests for Multiway Stops — ITE Journal, January 1994 Controlling Speeds on Residential Streets — ITE Journal, April 1989 M California MUTCD 2012 Edition (FHWA's MUTCD 2009 Edition, as amended for use in California) Page 135 a In addition, the use of YIELD or STOP signs should be considered at the intersection of two minor streets or local roads where the intersection has more than three approaches and where one or more of the following conditions exist: A. The combined vehicular, bicycle, and pedestrian volume entering the intersection from all approaches averages more than 2,000 units per day; B. The ability to see conflicting traffic on an approach is not sufficient to allow a road user to stop or yield in compliance with the normal right-of-way rule if such stopping or yielding is necessary; and/or C. Crash records indicate that five or more crashes that involve the failure to yield the right-of-way at the intersection under the normal right-of-way rule have been reported within a 3 -year period, or that three or more such crashes have been reported within a 2 -year period. os YIELD or STOP signs should not be used for speed control. Support: os Section 213.07 contains provisions regarding the application of multi -way STOP control at an intersection. Guidance: 07 Once the decision has been made to control an intersection, the decision regarding the appropriate roadway to control should be based on engineering judgment. In most cases, the roadway carrying the lowest volume of traffic should be controlled. o8 YIELD or STOP sign should not be installed on the higher volume roadway unless justified by an engineering study. Support: ovThe following are considerations that might influence the decision regarding the appropriate roadway upon which to install a YIELD or STOP sign where two roadways with relatively equal volumes and/or characteristics intersect: A. Controlling the direction that conflicts the most with established pedestrian crossing activity or school walking routes; B. Controlling the direction that has obscured vision, dips, or bumps that already require drivers to use lower operating speeds; and C. Controlling the direction that has the best sight distance from a controlled position to observe conflicting traffic. Standard: to Because the potential for conflicting commands could create driver confusion, YIELD or STOP signs shall not be used in conjunction with any traffic control signal operation, except in the following cases: A. If the signal indication for an approach is a flashing red at all times; B. If a minor street or driveway is located within or adjacent to the area controlled by the traffic control signal, but does not require separate traffic signal control because an extremely low potential for conflict exists; or C. If a channelized turn lane is separated from the adjacent travel lanes by an island and the channelized turn lane is not controlled by a traffic control signal. nw STOP signs shall not be erected at any entrance to an intersection controlled by traffic signals. Refer to CVC 21355(a). i i Except as provided in Section 2B.09, STOP signs and YIELD signs shall not be installed on different approaches to the same unsignalized intersection if those approaches conflict with or oppose each other. i2 Portable or part-time STOP or YIELD signs shall not be used except for emergency and temporary traffic control zone purposes. u A portable or part-time (folding) STOP sign that is manually placed into view and manually removed from view shall not be used during a power outage to control a signalized approach unless the maintaining agency establishes that the signal indication that will first be displayed to that approach upon restoration of power is a flashing red signal indication and that the portable STOP sign will be manually removed from view prior to stop -and -go operation of the traffic control signal. Option: in A portable or part-time (folding) STOP sign that is electrically or mechanically operated such that it only displays the STOP message during a power outage and ceases to display the STOP message upon restoration of power may be used during a power outage to control a signalized approach. Chapter 2B - Regulatory Signs, Barricades, and Gales - January 13, 2012 Part 2 - Signs 5 California MUTCD 2012 Edition (FHWA's MUCCD 2009 Edition, as amended for use in California) Page 137 Section 2B.06 STOP Sian Applications Guidance: of At intersections where o full stop is not necessary at all times, consideration should first be given to using less restrictive measures such as YIELD signs (see Sections 2B. 08 and 2B.09). o2 The use of STOP signs on the minor -street approaches should be considered if engineering judgment indicates that a stop is always required because of one or more of the following conditions: A. The vehicular traffic volumes on the through street or highway exceed 6, 000 vehicles per day; B. A restricted view exists that requires road users to stop in order to adequately observe conflicting traffic on the through street or highway; and/or C Crash records indicate that three or more crashes that are susceptible to correction by the installation of a STOP sign have been reported within a 12 -month period, or that five or more such crashes have been reported within a 2 year period. Stich crashes include right-angle collisions involving road users on the minor -street approach failing to yield the right-of-way to traffic on the through street or highway. Support: o3 The use of STOP signs at grade crossings is described in Sections 8B.04 and 8B.05. Section 2B.07 Multi -Way Stop Applications Support: of Multi -way stop control can be useful as a safety measure at intersections if certain traffic conditions exist. Safety concerns associated with multi -way stops include pedestrians, bicyclists, and all road users expecting other road users to stop. Multi -way stop control is used where the volume of traffic on the intersecting roads is approximately equal. o2 The restrictions on the use of STOP signs described in Section 2B.04 also apply to multi -way stop applications. Guidance: o3 The decision to install multi -way stop control should be based on an engineering study. oa The following criteria should be considered in the engineering study for a multi -way STOP sign installation: A. Where traffic control signals arejustified, the multi -way stop is an interim measure that can be installed quickly to control traffic while arrangements are being made for the installation of the traffic control signal. B. Five or more reported crashes in a I2 -month period that are susceptible to correction by a multi -way stop installation. Such crashes include right -turn and left -turn collisions as well as right-angle collisions. C Afinimum volumes: 1. The vehicular volume entering the intersection from the major street approaches (total of both approaches) averages at least 300 vehicles per hour for any 8 hours of an average day; and 2. The combined vehicular, pedestrian, and bicycle volume entering the intersection from the minor street approaches (total of both approaches) averages at least 100 units per hour for the same 8 hours, with an average delay to minor -street vehicular traffic of at least 30 seconds per vehicle during the highest hour; but 3. If the 85th -percentile approach speed of the major -street tre fic exceeds 40 mph, the minimum vehicular volume warrants are 70 percent of the values provided in Items 1 and 2. D. Where no single criterion is satisfied, but where Criteria B, C 1, and C.2 are all satisfied to 80 percent of the minimum values. Criterion C 3 is excluded from this condition. Option: os Other criteria that may be considered in an engineering study include: A. The need to control left -tum conflicts; B. The need to control vehicle/pedestrian conflicts near locations that generate high pedestrian volumes; C. Locations where a road user, after stopping, cannot see conflicting traffic and is not able to negotiate the intersection unless conflicting cross traffic is also required to stop; and D. An intersection of two residential neighborhood collector (through) streets of similar design and operating characteristics where multi -way stop control would improve traffic operational characteristics of the intersection. Chapter 2B - Regulatory Signs, Barricades, and Gates Part 2 - Signs January 13, 2012 TRAFFIC CALMING DO'S AND DON'TS Richard Drdul, P.Eng.' and Mike Skene, A.Sc.T.b Transportation professionals are divided over "traffic calming" or "traffic management" measures. The recent downturn in economic conditions means that in most communities, funds for new road construction are scarce. In addition, it is no longer politically desirable to continue to expand the arterial road system to accommodate traffic demand. In these circumstances, some transportation professionals contend that traffic calming measures must be implemented in order to manage traffic and maintain the livability of neighbourhoods. Others are opposed to the idea. They are concerned that there are no guidelines or national standards for traffic calming devices, and as a result devices might be used indiscriminately — often in response to public pressure — corrupting the road network and creating liability risks. THE PURPOSE OF THIS PAPER This paper is intended to assist both groups of professionals. Many transportation professionals who want to use traffic calming lack the knowledge and experience to confidently implement measures. This paper provides a summary of the basic principles of traffic calming, in a "do's and don'ts" format. This paper also identifies specific traffic calming measures which should be avoided — many of which are often requested by residents and other members of the community — and offers alternatives. Transportation professionals who have doubts about traffic calming cannot hope to avoid it forever. It is better that these professionals understand the benefits and limitations of traffic calming and how best to apply it, so that they may assist decision -makers and the public in making decisions. This paper will benefit these professionals by highlighting situations where traffic calming works and doesn't work, and providing suggestions as to the best process to follow in considering traffic calming measures. Much of the content of this paper is drawn from the authors' experience in planning and implementing traffic calming measures in small and large communities in British Columbia. This is supplemented with the experience of transportation professionals in 52 communities across Canada, who recently responded to a nationwide survey on traffic calming devices and practices conducted on behalf of the Transportation Association of Canada. THE PURPOSE OF TRAFFIC CALMING The purpose of traffic calming is to restore local streets to their intended function. In most cases, the problem is through traffic, speeding and/or noise, and traffic calming is often the most cost- effective solution to these traffic problems, especially as compared to the cost of widening an arterial road in order to ease traffic congestion or the limited effectiveness of a 4 -way stop sign. As a result, traffic calming often saves money indirectly, as compared to the costs of other solutions to a traffic problem. Traffic calming is not intended to save money at least not directly. Traffic calming requires spending money. In today's economic climate, it is often difficult to justify additional expenditures. Transportation professionals must be able to clearly explain the purpose and benefits of traffic calming in order to convince decision -makers that the expenditures are justified and needed. Senior Transportation Engineer, Urban Systems Ltd., Vancouver, B.C. — Member of ITE. Manager, Transportation. City of Victoria, Victoria, B.C. — Member of ITE. ITE 1994 Compendium of Technical Papers 491 7 COMMON TRAFFIC CALMING DEVICES Most transportation professionals rely on a half- dozen or so traffic calming devices which can be used in a wide variety of circumstances. These commonly -used devices are illustrated in Figure 1, and include speed humps, traffic circles, chicanes or pavement narrowings, semi -barriers, diverters, speed cushions and pedestrian refuges. Other traffic calming devices — such as rumble strips, speed tables and so forth — are usually intended for specific applications or are expensive to construct, and as a result are not widely -used. SOME CAVEATS It is important to remember that traffic calming is site-specific. In other words, just because a device works on one street or in one neighbourhood does not mean that it will work in another neighbourhood. Site-specific conditions must be considered in selecting appropriate traffic calming devices and measures. The "do's and don'ts" presented in this paper are — by necessity — generalities. In applying these "do's and don'ts," consider them in terms of the site-specific conditions and problems to be solved. In some cases, it may be appropriate to implement a "don't." Some transportation professionals will likely disagree with one or more of the do's or don'ts presented below. Some will disagree with the entire concept of traffic calming. This is to be expected, and in fact should be encouraged. Traffic calming is new and it is not an exact science — it can only benefit from disagreement, discussion and new ideas. As transportation professionals, we must remember what the objective of traffic calming is — to restore streets to their intended function — and must be willing to try non-traditional solutions to achieve this objective where conventional solutions have not worked. LIABILITY Many transportation professionals are enthusiastic about traffic calming, but are concerned about 492 ITE 1994 Compendium of Technical Papers Figure 1 — Traffic Calming Devices potential liability as a result of using a "new" device on a road. As with any other aspect of road design and traffic operations, liability concerns are best addressed by designing traffic M1 calming devices to accepted standards, adequately signing devices and regularly maintaining them. Experience indicates that this approach minimizes potential liability. Transportation organizations are responding to the need for design standards. The Institute of Transportation Engineers recently developed detailed design guidelines for speed humps. The Transportation Association of Canada is currently developing standards for traffic calming devices. Transportation professionals should assist these organizations as much as possible — your efforts and their efforts will benefit us all. Do's 1. Involve the community. • Do not develop or implement a plan without the community's involvement. No matter how technically sound a plan might be, it will not work as well if the community is not involved. • Involve "stakeholders" right from the start — residents, business operators, community associations. • Involving the community means more effort up front, but far less effort and cost in the long term. • The role of the transportation professional is not to dictate, but rather to educate and assist the community in selecting appropriate traffic calming measures. • Avoid the appearance of a pre -determined outcome. Obtain as much input as possible before undertaking any analysis or developing any plans, • Successful means of involving the community include a "walkabout" through the neighbourhood, a telephone "InfoLine," open houses, workshops to develop transportation plans, community meetings and newsletters. • Establish a neighbourhood transportation committee to channel requests and liaise with municipality. Make sure everyone knows what their role is by establishing a terms of reference for the committee. • Measure support for a plan through a neighbourhood -wide survey. Require at least '/, support from respondents. 2. Educate decision -makers • Avoid uninformed (often political or emotional) decisions. In a survey of 52 Canadian municipalities, Council directives and public requests were the basis for selecting almost twice as many traffic calming devices as engineering analysis and application of warrants, and the majority of devices selected were stop signs,' • Develop Council support for traffic calming measures based on technical merit. 3. Look at the arterial network first • No-one short-cuts unless there's a reason to — the reason is often congestion on nearby arterials. • There are a wide range of low-cost options available — fine-tune signal timings, add tum bays, implement turn prohibitions and parking restrictions. 4. Use appearances to send a message • Drivers react to perceptions. By altering drivers' perceptions of road conditions, their behaviour can be altered. • Pavement narrowings create "gates" entering residential streets, slowing and discouraging through traffic. • Raised crosswalks and intersections slow traffic and indicate priority for pedestrians. • Side streets can be reconstructed to appear as driveways at intersections, to discourage short -cutting traffic. 5. Favour self -enforcing measures • "Self -enforcing" measures maintain a 24-hour presence, and are effective without police enforcement. • Use speed humps (often referred to as "sleeping policemen") instead of speed restrictions. • Use semi -barriers and diverters instead of tum prohibitions. • Use traffic circles instead of 4 -way stops. ITE 1994 Compendium of Technical Papers 483 6. Consult with all services • Police, fire, ambulance, transit, garbage, street cleaning and snow plowing. • Minimize delays to emergency services, avoid impacts to transit services. • Eliminate a common basis for objecting to traffic calming devices. 7. Sign everything • Remember, most drivers are not traffic engineers! • Clarity is paramount. Sign to eliminate confusion and ambiguity. • There are no specific signs for most devices in the MUTCD. Use "keep right" signs for traffic circles (and supplement with arrows on pavement indicating direction of travel), "bump" signs for speed humps, and "curve ahead" signs for diverters. • Don't rely on signage alone. Back up signage with an education program explaining the benefits of traffic calming devices and how they work. Illustrate how drivers should negotiate traffic circles. • Be cautious — some signs may provoke negative reactions, such as truck route signs, no left turn signs or no entry signs. 8. Implement measures on an area -wide basis • Avoid creating more problems. Always consider the impacts on adjacent local streets and arterial roads. • Identify groups of measures to be implemented in stages, if Handing for the entire transportation management plan cannot be secured at once. 9. Monitor and follow-up • Need to report back to the community and Council as to the success of traffic calming devices. This helps to justify additional expenditures and enhances the credibility of the transportation management program. • Implement measures as "demonstrations" for six months or one year. Beware, though, that temporary installations can sometimes become permanent — therefore, design devices to be as safe and attractive as possible. • Have a "Plan B" ready in case a measure doesn't work — modify a measure, remove a device and replace it with a more appropriate device, or install additional devices. DON'TS 10. Don't believe everything you're told • Identify the real problem(s). Speed, volume and noise are frequent complaints, but often the real problem on a street is just one of these. • Quantify the problem. Undertake traffic counts, vehicle classification counts, speed studies, licence plate traces, parking surveys, and accident data analyses. • Remember that you're hearing mostly from people who are dissatisfied — there are other aspects to the situation that you're not likely hearing about. 11. Don't expect everyone to drive like you do • Some people are jerks, and will drive around or over barriers, diverters and other devices. • Some people don't understand traffic circles, no matter how well they are signed. • Some people resist change. 12. Don't use barriers unless absolutely necessary • Beware of setting a precedent — you could end up with barriers everywhere. • Barriers restrict access for people who live or work on a particular street. Often, as many residents don't want barriers as want them. • Barriers only divert traffic to other streets. • Use diverters instead — divert traffic rather than blocking it entirely. • Use semi -barriers instead — block only half the traffic, still leaving access for emergency and service vehicles. 13. Don't use 4 -way stops unless warranted • 4 -way stops are the #1 requested solution, and the most commonly -used device. 494 ITE 1994 Compendium of Technical Papers 10 • 4 -way stops are rarely a satisfactory or effective traffic calming device. Stop signs are intended to assign priority at an intersection., not to slow or divert traffic. • Stop signs can actually increase mid -block speeds.' • Unwarranted use of stop signs often results in "rolling stops" or no stops at all. • Stop signs are cheap, but police enforcement required to ensure compliance is expensive. 14. Don't use traffic calming on collector roads • Most traffic calming devices cause significant negative effects with traffic volumes of approximately 3,000 vehicles/day or more. • Collector roads are wider, and therefore it is more difficult to restrict traffic. • Drivers on collector roads often expect priority through traffic circles, increasing the risk of collisions. 15. Don't impose ridiculously low speeds • Avoid 30 km/h (20 mph) zones on collector and arterial roads. • Few drivers comply with reduced speed limits, and consequently the problem persists and the credibility of the transportation management program is reduced. • Speed limit signs are cheap, but frequent police enforcement is expensive. • Use speed humps on local streets instead. 16. Don't use just one device • Humps, traffic circles, chicanes and diverters are most effective when several are used throughout an area, as part of an area -wide plan. • Space speed humps every 100m (325 ft) to slow 85% of traffic to 45 km/h (28 mph) or less.' • Traffic circles are only effective in slowing traffic within 50m (150 ft) of the circle. 17. Don't use speed bumps • Speed bumps jolt vehicles, even at low speed, and create potential liability. Speed bumps may cause damage to vehicles, and injury to passengers and cyclists. • Speed humps are not a substitute for bumps — speed humps are not effective below 25 km/h (15 mph). 18. Don't impede other modes • Bus gates permit bus access while obstructing other vehicles. • Speed cushions slow automobiles, but allow bus wheels to pass outside the cushions. • Contra -flow bicycle lanes and gaps in barriers accommodate bicycles. • Median refuges make it easier for pedestrians to cross streets. • Rolled curbs allow large trucks and buses to mount devices if necessary. 19. Don't prohibit parking on residential streets • On -street parking narrows the road, slowing traffic. • Parking both sides is acceptable on roads as narrow as 7m (23 ft). • Establish "no parking" times for street sweeping and snow plowing. 20. Don't expect to solve every problem • Some problems cannot be addressed by a neighbourhood -wide plan, such as regional traffic issues. • Some problems cannot be resolved at a reasonable cost. For example, it may simply be too expensive to acquire property to widen an intersection or road. • Refer other problems to the appropriate agency, such as the planning department, transit operator, bylaw enforcement and the police. REFERENCES I. Skene, Mike. Neighbourhood Traffic Calming Devices in Canada, Transportation Association of Canada. 1993. 2. Noyes, Patricia. "Responding to Citizen Requests for Multiway Stops," !TE Journal, January, 1994, 3, institute of Transportation Engineers. Guidelines for the Design and Application of Speed Humps, Washington, D.C., March 1993. ITE 1994 Compendium of Technical Papers 495 Responding to Citizen Requests for Muttiway Stops BY PATRICIA B. NOYES The use of multiway stops for speed control is a subject that has received a great deal of attention from citizens and far too little conclusive discussion by traffic engineers. In an effort to address the ongoing surge of citizen requests to install four-way stops for speed control, the staff of the Boulder (Colo,) Transportation Division com- pleted a literature search on the use of multiway stops and conducted local studies on their effectiveness and driver compliance. The purpose of this study was to identify the issues related to the use of multiway stops and to help citi- zens understand some of the negative side effects of their use. The effort was intended to develop an information piece that could be used in discussions with citizens. The remainder of this article is intended for that use and can be used as a basis for other local efforts to develop public information strate- gies. Considerations for the Installation of Stop Signs Multiway stop signs usually are requested to address speeding and safe- ty problems in residential areas. Boulder's studies on compliance and speed were an attempt to examine the effectiveness of stop signs for these Conversion Factors .To convert from IQ mutt ply -4 it m 0.3048 mph kmh 1.609 uses. in addition to these issues, there are several other areas that need to be examined and discussed in considering the use of multiway stops. A number of these are outlined below. Compliance Stop signs are used to improve the safety of an intersection by assigning right-of-way; therefore, compliance with stop signs is essential for their effectiveness. Several studies have shown that in situations where stop signs are installed but are not warrant- ed, based on nationally adopted stan- dards, there is a low level of compli- ance. In these cases, motorists were observed either rolling or running a stop sign. When a driver does not believe that a restrictive sign appropri- ately reflects the conditions, the driver often disregards it. This was studied in Boulder and the results are summarized in Table 1. Stop sign compliance studies were completed at nine four-way and four three-way stop locations. Of the 900 cars observed at the four-way locations, 23 percent made a full stop. Of the 350 vehicles observed at three-way locations, 7 per- cent stopped. The majority of the observed cars at all locations made a rolling stop (slowed to less than 3 miles per hour (mph) but did not come to a complete stop). The highest compliance levels occurred at the higher volume, four-way stop locations. The three locations that significantly exceeded the average com- pliance rate involved higher volumes with higher percentage side street traf- fie. These locations experienced 39 per- cent to 40 percent compliance. The one other location that exceeded the aver- age compliance level experienced 26 percent compliance. This location would require tree trimming for sight distance in order to remove the stops from the main street. Three-way stops showed the lowest compliance with 11 percent of the 350 cars observed driving through the stop sign in excess of 3 mph. Speed Control There is a common belief among the general public that stop signs provide relief from traffic speeding problems. On the face, it would appear reasonable that when approaching a stop sign, motorists have to slow down. However, studies conducted nationwide have shown that the speeds within a block of the stop sign are either unaffected by the stop sign or, in some cases, actually increase. At the point of installation, speeds are reduced, but the effect on traffic approaching or leaving the con- trolled location is negligible. Some motorists actually increase their speed to make up for the inconvenience. Speeds approaching and down- stream of multiway stop signs in Boulder were studied are summarized in Table 2. Speed studies were conduct- ed an average of 500 feet (ft) from the stop sign on the approach to, and down- stream from, four four-way and two three-way stop locations. The average 85th percentile speeds (85 percent of the vehicles traveled that speed or less) were 35 mph on the approach and 34 ITE JOURNAL • JANUARY 1994 • 43 I2 NEVER -FAIL LOOP SYSTEMS 10 YEAR WARRANTY o$KT LEADER 0IN Looe TECHNOLOGY C SQUAREU ROUND T 0 M BUILT - re mean vehicular speeds were 31 LONG QUADRAPOLB xioov0 four -Way Stops 9 76 FEATURES ' >allosple & Juslard Location ASPHALT—RUBBER FILLED Roll POLYPROPYLENE CONSTRUCTION. ! FLEXIBLE/FOLDABLE EXPANSION t CONTRACTION JOINTS, / LOOPS IN EXCESS OF 100 FT. t EASILY HANDLED. 8 82 HERMETIC ASSEMBLIES — 4 LAYERS 6 OF MOISTURE PROTECTION. 21 RESISTANCE TO GROUND—TYPICALLY P OFF SCALE. — O—STABILIZED QUALITY OF LOOP 100 DOES NOT FALL OFF WITH TIME. 7 82 6-19/4:30 26 USER REFERENCES AVAILABLE m T 100 Alpine & 13th NEVER -FAIL To LOOP SYSTEMS 3( ''6021 S.W. 48TH AVE. 39 :.PORTLAND OR 97221 fa (503) 244-6345 8� m 44 - ITE JOURNAL - JANUARY 1994 Table 1. City of Boulder Stop Sign Compliance Study almla & 26th Stop Sign Compliance re mean vehicular speeds were 31 comparable or greater than speeds four -Way Stops 9 76 15 100 >allosple & Juslard Location Stop Roll No Stop Total Datelfte % % % Observed Maxwell & 9th 26/4:305:30 8 82 10 50 6-20/3:303:39 21 75 4 100 Manhattan & llllnl 9 100 verage Compliance 7 82 6-19/4:30 26 71 3 100 Alpine & 13th 6-19/3:42-3:58 39 60 1 100 Balsam & 19th 6-19/3:303:38 40 59 1 100 Walnut & 33rd 6-19/3:12-3:22 19 79 2 100 Arapahoe & 6th 6-19/2:503:05 39 60 1 100 Nonderland & Poplar X29/8:08-8:40 11 82 7 100 lraaklawn & Laurel x28/4:20-5:05 7 88 5 100 ;allege & 7th ,-29/4:205:30 6 79 15 100 Overage Compliance 23 73 4 900 hree-way Stops almla & 26th mean speed was 30 mph. These are re mean vehicular speeds were 31 comparable or greater than speeds -20/3:47-4:14 9 76 15 100 >allosple & Juslard Safety y th. The average 85th percentile speed -22/4:00-4:55 11 80 9 100 Iblon & ToecMI and after the installation of multtway rh locations was 34 mph and the stops. In some cases the accident rates 26/4:305:30 8 82 10 50 anhattan & Cimmaron 21/4:33-5;15 2 89 9 100 verage Compliance 7 82 11 350 ph downstream from the stop sign, mean speed was 30 mph. These are re mean vehicular speeds were 31 comparable or greater than speeds )h and 30 mph, respectively. observed on other Boulder residential Two of the six locations were posted streets. mph and the others were posted 25 Safety y th. The average 85th percentile speed r the 30 mph locations was 36 mph Studies have shown differing effects d the mean speed was 32 mph. The on accident rates at intersections before :rage 85th percentile speed for the 25 and after the installation of multtway rh locations was 34 mph and the stops. In some cases the accident rates increased, in others they decreased and in still others there were no significant changes. General engineering belief is that the unwarranted use of stop signs potentially decreases safety at the inter- section because of the disregard of these controls as observed in the com- pliance studies; however, no study has definitively proved this. A recent article on Chicago's (111.) experience with the use of multiway stops indicates that the accident rates might be reduced at low- volume intersections (see LaPlante and Kropidlowski ' ). Motorist Delay The unwarranted use of stop signs increases vehicle delay. Where the proper use of muldway stops occurs, the increase in delay on the main street is offset somewhat by the reduced delay on the side street. However, in an unwarranted situation, there is minimal delay on the side street and overall delay is increased significantly by the required stop of all traffic on the main street. Excessive Restrictions on the Public The unwarranted use of stop signs .creates excessive restrictions on the motoring public. This creates a great deal of frustration and, as previously mentioned, disrespect for traffic control devices. It also is contradictory to the legislative intent of the Uniform Vehicle Code and Model Traffic Ordinance 1987, which states that, "The proper purpose of all traffic legislation is not to impose unnecessary or unrea- sonable restrictions on highway traffic, but to insure, as far as this can be done by law and its application, that traffic shall move smoothly, expeditiously and safely." The motto of the committee is "Safety with Freedom Through Law," which summarizes its philosophy "to provide to every highway user, through law, a maximum degree of safety within the framework of traditional freedoms." The Traffic Control Devices Handbook states, "The most effective .traffic control device is that which is the least restrictive while still accomplishing the intended purpose."2 Environmental Effects The unwarranted use of stop signs affects the environment in terms of air pollution, noise impacts and fuel con- sumption. Air Pollution The effects of stopping and idling increase automobile exhaust. A study of 10 four-way stop intersections in Michigan found: "The total additional emissions of carbon monoxide were 1,287,500 pounds per year, hydrocar- bons totaled 79,200 pounds per year and oxides of nitrogen totalled 83,000 pounds per year. These quantities indi- cate the magnitude of the additional emissions attributable to four-way stop sign control at these intersections." Noise Impacts Additional traffic noise also is asso- ciated with stopping and starting. Braking and acceleration increase tire noise and engine noise. Stop signs also increase the amount of time any one vehicle is at a particular point. Therefore, residents living near the stop controlled intersection will experi- ence an increase in traffic noise. Fuel Consumption Stopping, accelerating and idling also increase the amount of fuel con- sumed by a vehicle. A California study in 1982 found that deceleration and acceleration for each stop an average passenger car makes, 0.0173 gallons of fuel is consumed, This would mean that for every unwarranted stop sign installed on a street with 10,000 cars per day, 173 additional gallons of gasoline would be consumed in a day, or 63,145 additional gallons would be consumed in a year. Pedestrian Exposure Although it is commonly believed that stop -controlled intersections pro- vide increased safety for pedestrians, this might not be accurate at locations where adequate gaps in traffic exist and the stop signs are unwarranted. If a stop sign is installed under these conditions, a vehicle is present at the intersection for a much longer period while it slows, stops and accelerates. This actually causes an increase in the exposure time EVIPAS ana EZVIPAS • Optimized settings for max. green, min. green, unit extension, added initial, max, initial, time before reduction, time to reduce, min, gap and more • Pretimed, semi -actuated, fully -actuated, and volume -density • MOEs. include delay, operating costs, fuel consumption and and emissions • Dual -ring eight phases Including pedestrian • Up to five approaches • Output summary of delays • WindowsTM-like user interface • Stochastic, microscopic and event -based • Context -sensitive help VIGGEN CORPORATION 7601 Lewlnsville Road Suite 460 McLean, VA 22102 Tel: 1.800.260.1001 Fax: (703)903.4996 Only $185 Call for free demo ITE JOURNAL • JANUARY 1994 • 45 Table 2. City of Boulder Speed Study Speed Studies Stop Location Approach Speed Street/posted speed 85th% Average Balsam & 19th 19th Street/30 mph Walnut & 33rd Walnut/30 mph Brooklawn & Laurel Brooklown/25 mph Arapahoe & 6th Arapahoe/25 mph N. 26th & Kolmla N. 26th/25 mph Glllasple & Emerson Glllasple/25 mph Average 85th MeonSpeed 38 33 35 31 33 30 33 29 37 32 33 29 35 31 100 observations were made of each location, 50 each direction. Speeds were shot 400ft.-600 ft. from stop sign. Downstream Speed 85111% Average 39 35 32 29 32 29 of the pedestrian to vehicles and reduces or eliminates the natural gaps in traffic at the intersection by increas- ing the time each vehicle is present. The other major exposure issue is that of the pedestrians to drivers who will violate the stop control. As has been observed, compliance at unwar- ranted stops is low and this leaves pedestrians vulnerable to these viola- tions. This presents a particular hazard to children, whose size might make them less immediately visible to dri- vers. Clarity of Traffic Control 31 Traffic control devices are designed 28 to inform drivers of roadway and traffic conditions with minimal opportunity for 37 confusion or misinterpretation. Stop 32 signs are used to assign right-of-way to 32 a through street by stopping traffic on 29 the minor street. The motoring public expects the uniform application of traf- 34 fic control devices and would not expect 30 a stop sign on the major street. This potential for confusion aggravates the observed compliance problem and ere - Alien Engineer Emerges Flom UFS! Introduce yourself as an engineer, and some people look at you like you're from Outer Space. True, you do spend your time turning today's science fiction into tomorrow's everyday reality. But when last have you introduced your fellow earthlings to the world of engineering? Engineers make contact with native lite Corms every year during National Engineers Week, On national television, during the Future City Competition. In the nation's classrooms, for the Discover"E" program. Even at shopping malls, in the new "Engineering Goes Public" technology fairs. Everywhere across the country, engineers like you will be increasing public appreciation of the engineering profession by celebrating the positive contributions o engineers make to our quality of life. "it looked like Elvisif" cries startled bystanded 46 • ITE JOURNAL • JANUARY 1994 This year, don't be an alien in your community. Your free National Engineers Week planning kit gives you everything you need to get involved. Write: National Engineers Week, P.O. Box 1270, Evans City, PA 16033. Then hop in your flying saucer and head off for some close encounters of the educational kind. But hold the Elvis impersonations... please. ENGINEERS Turning Ideas Into Reality, NATIONAL ENGINEERS WEEK© FEBRUARY 20-26,1994 National Engineers Week 1994 is a cooperative venture of dozens of engineering and technical societies and major corporations. 15 ates a potential safety hazard. Legal Responsibilities Variations from accepted warrants without documented exceptional condi- tions present potential liability concerns for the responsible jurisdiction. If a stop sign installation could be considered irresponsible or in clear contradiction to accepted standards, liability suits could result. Summary Existing studies and information on the use of multiway stop signs are far from conclusive. There are however, a variety of studies that provide some important insights into their use. The recent article by La Plante and Kropidlowski provides a comprehensive review of the use of accident experience associated with the use of multiway stop signs. It recommends that the existing Manual on Uniform Traffic Control Devices warrants for multiway stops be reviewed and potentially revised to address local residential streets in urban areas more effectively. Although a review of the warrants might be appro- priate, it should be done with respect to a variety of implications. The issues for consideration dis- cussed in this article include: ■ Compliance ■ Speed Control ■ Safety ■ Motorist Delay ■ Excessive Restrictions on the Public ■ Environmental Effects ■ Pedestrian Exposure ■ Clarity of Traffic Control ■ Legal Responsibilities These issues should be included in any discussion on the use of multiway stop signs. This list and the discussion of these issues is an attempt to open the discussion in a way that helps engineers and citizens alike examine the implica- tions of using multiway stops. There are certainly other concerns that could be added to this list based on the experi- ence of others. The engineering community and the public need to consider all of the impli- cations of multiway stop sign use and continue to study the impacts of their use so in order to work together to appropriately address specific traffic control issues. References 1. La Plante, John N. and Chester R. Kropidlowski. "Stop Sign Warrants: Time for Change." ITEJournal, Vol. 62, No. 10 (October 1992):25-29. 2. U.S. Department of Transportation. Traffic Control Devices Handbook, Washington, DC: Federal Highway Administration, 1983, Bibliography American Traffic Safety Services Association Inc. ATSSA Newsletter, 1989, Baumgaertner, William E. "In Search of Effective Speed Control." Institute of Transportation Engineers Technical Notes, December 1980,12-16. Beaubien, Richard F. "Citizen Participation in Traffic Safety." ITE Journal, Vol. 52, No, 3 (March 1982):29-31. Beaubien, Richard F. "Controlling Speeds on Residential Streets." ITE Journal, Vol. 59, No. 4 (April 1989):37-39. Beaubien, Richard F. "Stop Signs for Speed GuidSIGN' Makes Sign Layout Easy. Transoft Solutions' new GuidSIGN software package for AutoCAD takes all the work out of designing and laying out highway guide signs. With GuidSIGN, even the most complex signs go from conception to dimensioned layout in minutes. GuldSIGN Features include; • Standard highway letters and symbols based on the "Manual On Uniform Traffic Devices". • Standard C, D and E(M) highway letter fonts. Standard arrows and route shields. • Automatic sizing and creation of sign borders. • Automatic letter spacing (kerning). • Left, right and center text alignment. • Automatic and adjustable line spacing. • Sign construction panel size optimization. • Optional letter height calculation. • Letter and symbol location table. Salt", Edit - rrr Saeea . - SM Darden Start ft. - Sl Upate - RD Letter Table - TEL Dl Mcoaleo. - DIM T.M Laft n MOM TM canter TC hxt Mfl - TRL Me.t DIDht -IDR Meateentee - TIC cln,pe - lol Upd.ta NP Sp. Upaata - Sar lel r: SMrt - RPl any PMI ;nt.e - SCI W NO .N. Loop - SM2 u.. SWr - SMS DrMd vam.: ins. - r rlMe I• - 1001 in ea. a=at - amDm t.RdLR - D11I Transoft Solutions P�SODp 6 5 Suite 5, 7171 Blundell Road Richmond, B.C. V6Y 1J5 Phone: (604) 244-8387 Fax: (604) 244-1770pe0 ITE JOURNAL • JANUARY 1994 • 47 1 V Control?" Traffic Engineering, November 1976,26-28. Briglia, Peter M., Jr. "An Evaluation of 4 -Way Stop Sign Control." ITE Journal, Vol. 52, No.8 (August 1982):16-19. Chadds, Himmat S. and Everett C. Carter. "Multi -Way Stops—Have We Gone Too Far?" ITE Journal, Vol. 53, No. 5 (May 1983):19-21, Holmburger, Wolfgang S., et al. Residential Street Design and Traffic Control. Englewood Cliffs, NJ: Prentice -Hall, 1989. "Indiana Suggests Ways to Halt Stop Sign Misuse." TRANSAFETY Reporter, Vol. VJI, No.2 (February 1989):7. Lum, Harry S. and Martin R. Parker Jr. "Intersection Control and Accident Experience in Rural Michigan." ITE Journal, Vol. 53, No. 5 (May 1983):27-29. National Committee on Uniform Traffic Laws and Ordinances. Uniform Vehicle Cade and Model Traffic Ordinance, 1987. U.S. Department of Transportation. Manual on Uniform Traffic Control Devices. Washington, DC: Federal Highway Administration, 1988. 1 SOLAR .ammum 48 • ITE JOURNAL • JANUARY 1994 Patricia B, Noyes is a principal in the engineering and management con- sulting firm of Pat Noyes & Assoc- inies. Previously, she was traffic operations engineer for the city of Boulder, Colo„ for eight years and transportation planning engineer for Boulder County before that. She current- ly serves as secretary/treasurer for the Colorado/Wyoming Section of ITE and chaired the section's Technical Committee on Residential Speed Control in 1987-88. She received an M.S.C.E. from the University of Colorado, Boulder; and M.A. from McMaster University, Hamilton, Ontario; and a B.A. from Northwestern University, Evanston, Ill. She is an Associate Member of ITE. ITE's Electronic Bulletin Board The ITE Bulletin Board System can be accessed by anyone with a modem and PC by dialing 800/982-4683. The bulletin board allows users to: •Exchange technical information -Make technical inquiries *Leave or get messages *Download files *Get the latest information on Positions available or wanted up to six weeks before publication in ITE Journal *Access lists of Journal articles *Review "Washington Reports" • And much more If you need more information about what the BBS has to offer or have questions about using it, call the systems operator at ITE Headquarters at 202/554-8050. CHOOL ZONE FLASHER SOLAR ENERGY IS FREE UNBREAKABLE SOLAR PANEL RELIABLE RTC TIME SWITCH QUALITY GEL CELL BATTERY STANDARD SIGNAL HEAD MODULAR VOLTAGE REGULATOR CURRENT/ VOLTAGE METER DEPENDABLE RTC FLASHER ANNUAL PROGRAMMING AUTOMATIC DAYLIGHT SAVINGS TIME LEAP YEAR COMPENSATION CALL TODAY FOR DETAILS RTC RTC Manufacturing, Inc. P. O. Box 150189 Arlington, TX 78015 (800) RT"721 In Texas (8 17) 860-1217 Controlling Speeds on Residential Streets BY RICHARD F. BEAUBIEN Complaints of speeding on residential streets are a continuing problem for local traffic engineers and police depart- ments. The observations in this article describe the experiences of Troy, Michigan, in dealing with this problem over the past decade. Comparisons of 1975 speed study and observance study results with 1985 and 1986 results at the same locations are included. The Nature of the Problem Because the complaints of speeding in residential areas are often emotional, it is important to put the problem into perspective. By understanding the nature of the problem, we may be able to arrive at better solutions for our citizens. The problem is partly social and partly political. Elected officials confronted with a citizen request for a stop sign might find it easy and inexpensive to grant the request, thus demonstrating their "compassion" and "concern for local needs." Although this demonstration of compassion is inexpensive in terms of immediate capital costs, its long- term impact can be detrimental to public health, safety, and welfare. Studies have shown that unwarranted stop signs are ineffective in controlling speeds; such signs are often disregarded, leading to a lack of respect for traffic control devices.' In 1987, 90% of all accidents and 96% of the injury accidents in Troy occurred on arterial, rather than residential, streets. This suggests that transportation professionals should be spending more than 90% of their time dealing with the problems of accidents on arterial streets. However, because the speeding problem in residential areas is "close to home;' traffic engineers and police departments spend a disproportionate amount of their time addressing problems on local streets, which are not connected to accident experience. Speeding on residential streets is a season- al problem. In northern climates, such as in Michigan, the complaints of speeding on residential streets virtually disappear during the months of November through March; when residents spend less time out doors, the problem or perceived problem seems to disappear. A 25 -mph speed limit may be unreason- ably low in new subdivision areas with adequate street design standards. The national basic speed limit recommended in the Uniform Vehicle Code is 30 mph. In Michigan, the lowest speed limit permitted under state law (except in park areas) is 25 mph. Naturally, residents insist that the speed limit be as low as possible in their neighborhood, although the design speed on their street may exceed 25 mph. Motorists who travel local streets every day tend to travel closer to the design speed than the speed limit, and this creates observed speeds in excess of the posted speed limit. This condition is viewed with alarm by neighborhood residents, but it may not actually be a traffic safety problem because the design speed may be greater than 25 mph. The speeding problem on residential streets tends to become associated with the problem of through traffic in residential areas. The through traffic is, in part, a symptom of inadequate capacity on major arterial streets. If adequate capacity were available on the arterial streets, "outsiders" would stay on arterial sheets rather than seek alternate paths through residential areas. Stop Signs Not Effective Many citizens, particularly those concerned about the safety of their children, suggest that "maybe a stop sign will slow traffic on our street" Before -and -after speed studies conducted in the City of Troy indicate that stop signs are not effective in controlling speeds. Compliance with these stop signs is very poor, and over a period of years the compliance degrades to a point where motorists behave as if the sign were not present at all. This degradation is shown in Table 1, which compares the compliance rates for stop signs installed to control speeds on residential streets in Troy. The locations of these stop signs in relation to the surrounding street system are shown in Figures I and 2. Tables 2, 3, and 4 compare the results of 1975 speed studies on streets with unwarranted stop signs to 1986 study results on the same streets. Sample sizes for these speed studies were limited because of the relatively low volumes present on these residential streets. Observers were instructed ITE JOURNAL • APRIL 1989 , 37 to collect as much data as possible in a 30 - to 60 -minute time period. As a result, samples were generally in the size range of 40 to 100. In all cases the sample size was greater than 40. Two-way daily traffic volume is approxi- mately 1500 on Anvil Drive, 2700 on Niagara Drive, and 1100 on Robinwood Strut, Peak hour volumes are approximately 170 on Anvil Drive, 300 on Niagara Drive, and 120 on Robinwood Street. All of the intersection study sites were relatively flat in terrain, so there were no sight distance restrictions resulting from vertical curves. Horizontal alignment of these streets has a minimal impact on available sight distance. On Anvil Drive, horizontal alignment is relatively straight for a distance of 500 feet to the north and south of Forge Drive. 1t is also straight for a distance of 900 feet north and 700 feet south of Kettle Drive. On Niagara Drive, horizontal alignment is straight for a distance of 600 feet to the west and 300 feet to the east of Eagle Drive, On Robinwood Street, horizontal alilgnment is straight for a distance of 300 feet to the west and 1000 feet to the east of Van Courtland Street. Intersection sight distance at all locations is limited by houses at the corners. Houses at the Anvil/Forge intersection are 40 feet from the edge of the pavement, and houses at the Niagara/Eagle intersection aro 40.50 feet from the edge of the pavement. Houses at the Robinwood/Van Counland intersection are 30 feet from Van Courtland Street and 50 feet from Robinwood Street. Unwarranted stop signs were placed on Anvil and Niagara in 1975. In 1979 the Anvil/Forge intersection was converted to a four-way slop, despite the fact that warrants for a multi way stop were not met. Unwar- ranted stop signs were placed on Robmmixid in 1964; they were removed for a brief trial period in 1975. In each case, the average speed in 1986 was higher than in 1975 at the same location. Although the differences may not be statistically significant, it seems apparent that the passage of time does not make stop signs effective in controlling speeds. Speed studies were made using a radar unit on an unmarked city car. The highest speed observed for each vehicle for a distance of approximately 500 feet either side of the intersection was the speed recorded. Stop signs installed in the City of Troy that do not meet the warrants established in the Manual on Unifarm %fflc Control Devices are considered to be legal and enforceable. 38 • ISE JOURNAL • AFRfL 1969 The signs were installed pursuant to an ordinance adopted by the Troy City Council, the local legislative body. There is no known case law in Michigan that would force the removal of unwarranted stop sign installations. The Solution ... In Parts There is no one, simple answer to the problem of speeding in residential areas. The traffic engineering department in the City of Troy has suggested to residents that the neighborhood itself must take some respon- sibility for the solution. A majority of the speeding violations issued in residential areas go to residents of that street or to streets in the immediately surrounding area. Residents of the immediate area can thus address the problem by increasing the awareness of the problem in the neighborhood and by assisting the police department. A program in which license plate number reports are used to identify the owners of vehicles found to be speeding has been somewhat successful in controlling speeds. In that program, neighborhood residents report license plate numbers of speeding Table 1. Stop Sign Observance on Selected Residential Streets In Troy Niagara Drive Full stop 51 21 Roll stop 34 74 No stop 15 5 Robinwood Street Full stop 26 16 Roil stop 48 65 No stop 26 19 Figure 1. Street plan showing Anvil and Niagara study sites. 11 1975 1985 L Location (%) (%) Anvil Drive Full slop 25 13 Roll stop 64 60 No stop 11 27 Niagara Drive Full stop 51 21 Roll stop 34 74 No stop 15 5 Robinwood Street Full stop 26 16 Roil stop 48 65 No stop 26 19 Figure 1. Street plan showing Anvil and Niagara study sites. 11 vehicles to the police department and the police department locales the vehicle owner through the secretary of state's records; the police department then writes to the vehicle owner, requesting safe driving practices and compliance with local traffic ordinances. One of the positive effects of this program has been to convert many of Troy's younger driven into pedestrians: These younger driven found that a vehicle was no longer available to them after the vehicle owner (a parent) learned how it was being used. The City of Troy has a committee of citizens appointed to advise the City Council on proposed traffic regulations. This Traffic Committee gives a "first hearing" to neighborhood traffic problems and recom- mends new traffic regulations for City Council approval. Traffic Committee involvement is important because it allows the light of objectivity to shine on the problem before the political decision is made? Discussions between committee members and citizens concerned about speeding on their neighborhood streets are helpful in achieving an understanding that stop signs are not a panacea and that there is no one easy solution. This discussion itself is part of the solution to the social and political aspects of the problem. References I. Beaubien, Richard F. "Slop Signs for Speed Control?" Tmffic Engineering 46(Nwember 1976): 26.28. 2. Beaubien, Richard F. "Citizen Participation in Traffic Safety." ITE Journal 52(March 1982):29-31. ■ Richard F. Beau- bien is the transpor- tation director for Hubbell, Roth and Clark, Inc., consuh- ing engineers, Bloomfield Hills, Michigan. Before entering this position in 1989, he served 14 years as transportation director for the City of Troy, Michigan. Beaubien received his M.S.C.E., B.S.C.E„ and A.B. degrees from the University of Michigan. Beaubien is a registered pro- fessional engineer in Michigan, Illinois, and California. He is a Fellow Member of the Institute of Transportation Engineers and currently serves as the Institute's Inter- national Vice -President. Table 2, Speed Studies, Anvil Drive Speed Without Stop With Stop With Stop (mph) Signs, 1975 Signs, 1975 Signs, 1986 _ Low 15 15 18 Average 24.1 24.6 26 851h Percentile 28 28 30 High 38 35 34 Table 3. Speed Studies, Niagara Drive Speed Without Stop With Stop With Stop (mph) Signs, 1975 Signs, 1975 Signs, 1986 Low 15 15 20 Average 23.8 25.2 26 85th Percentile 26 29 29 High 34 34 33 Table 4. Speed Studies, Robinwood Sheet Speed Wllhout Stop With Stop With Stop (mph) Signs, 1975 Signs, 1975 Signs, 1986 Low 10 13 21 Average 23.4 24.4 30 65th Percentile 30 30 34 High 38 38 42 Figure 2. Street plan showing Robinwood study site, ITE JOURNAL • APRIL 1989 • 39 Z0