McMAHON ASSOCIATES, INC. 425 Commerce Drive Suite 200 Fort Washington, PA 19034 p 215-283-9444 f 215-283-9445 www.mcmtrans.com July 15, 2011 Mr. Gerry Condon Pocono Woodland Lakes Property Owners Association P.O. Box C 141 Marigold Lane Milford, PA 18337 PRINCIPALS Joseph W. McMahon, P.E. Rodney P. Plourde, Ph.D., P.E. Joseph J. DeSantis, P.E., PTOE John S. DePalma William T. Steffens Casey A. Moore, P.E. Gary R. McNaughton, P.E., PTOE ASSOCIATES John J. Mitchell, P.E. Christopher J. Williams, P.E. John F. Yacapsin, P.E. RE: Roadway Evaluation of Speed Bumps Aspen Drive/Arrowood Drive Corridor McMahon Project No. 910696.11 Dear Mr. Condon: As requested, McMahon Associates, Inc. has completed an evaluation of the Aspen Drive and Arrowood Drive corridor speed bumps within the Pocono Woodland Lakes community to determine their effectiveness in reducing vehicle speeds and their appropriateness within the community in their current state. Based upon a discussion with community representatives, it is our understanding that the need for this evaluation arose from concerns regarding the design and location of the existing speed bumps along these two roadways, which includes concerns from local emergency services providers regarding the impacts to their equipment and response times, as well as school buses transporting special needs students in terms of traveler comfort. The following is a summary of the results: The vehicle speeds measured near and in between the speed bumps indicates that the speed bumps are not effective in controlling vehicle speeds, as the 85 th percentile speeds are well over the posted speed limit for the community. It is recommended that the speed bumps be removed due to the following conditions: - The speed bumps located along Aspen Drive are located at the all way stop controlled intersection of Ash Lane (north) and to the south of Pitch Pine Lane. The placement of these speed bumps at the all way stop controlled intersection appears to be more for encouraging vehicles to comply with the traffic control signs rather than reduce vehicle speeds. As a result, vehicle speeds along Aspen Drive are not impacted by their placement. - Along Arrowood Drive, the two speed bumps appear to be placed at better locations, not adjacent to any intersections; however, they are not impacting travel speeds, which can be attributed to their visibility and design. - The visibility of the speed bumps is an issue at all locations, as they blend into the roadway and limited signage is provided warning vehicles that they are present. As a result, the speed bumps are disregarded by vehicles. Corporate Headquarters: Fort Washington, Pennsylvania Serving the East Coast from 10 offices throughout the Mid-Atlantic, New England, and Florida
Mr. Gerry Condon July 15, 2011 Page 2 - The use of the yellow boulders located next to the speed bumps also creates a safety hazard for the community in the event that a vehicle runs off of the road. - The design and use of the speed bumps are not in accordance with current traffic calming practices. Meet with the association to discuss setting up a formal traffic calming program that would allow residents to make requests for traffic calming devices and create set standards across the community regarding their placement and use. As part of this formal program, the devices should also be tested prior to permanent installation to ensure that the devices are having the desired impact. If the community would like to continue to utilize some type of traffic calming device to control vehicle speeds, then it is our recommendation that portable speed humps, which could be removed during winter months, be utilized along with appropriate signage. Speed humps are more effective at reducing vehicle speeds, and if they can be removed during the winter months, then the entire roadway can be plowed, which will not create an unsafe driving condition. Speed humps also result in less vehicle deflection for emergency vehicles and do not impact their travel times as much as speed bumps. If utilized, the speed humps should be strategically placed at mid block locations along both Arrowood Road and Aspen Drive. Current Roadway Conditions The Pocono Woodland Lakes Property is a private community that is responsible for the maintenance and operations of over 32 miles of roadway, of which there are numerous points where non residents can enter the community. Aspen Drive and Arrowood Drive form the shortest link between two public roads: Log Tavern Road (County Road 2006) and Raymondskill Road (County Road 2009). Without the use of these private roads, the distance required to travel from Log Tavern Road/Aspen Drive to Raymondskill Road/Arrowood Drive is over 8 miles, which can add an additional 15 minutes to area travel times. In emergency situations, this additional 15 minutes is crucial, and as a result, emergency providers are permitted to utilize the private roads. However, the community would like to limit the use of their roadways from non residents as nonresidents do not contribute to the maintenance of the roads. With the numerous entry points into the community, there is only one gatehouse that is located at the intersection of Log Tavern Drive/Aspen Drive. However, as the gatehouse is not manned during all times, there are opportunities for non residents to enter the community in this area. To the north along Raymondskill Road, non residents can easily access either Nelson Road or Buckeye Lane to Arrowood Drive to access Aspen Drive. As there are other roadways maintained by the community along Raymondskill Road, it would not be practical to have gatehouses at all of the locations.
Mr. Gerry Condon July 15, 2011 Page 3 In general, both Aspen Drive and Arrowood Drive are narrow roads with cartways (paved edgeto edge) ranging from 16 to 17 feet. Both roadways include numerous vertical and horizontal curves and have posted speed limits of 25 miles per hour. The signing of the posted speed limit is inconsistent throughout the roadway, in terms of the types of signs used and the placement of the signs. The speed limit signs should be in compliance with current standards in terms of size and type to be properly enforced, and the signs should be placed consistently throughout the roads near intersecting streets. If the signs are not properly placed, then drivers who are ticketed for speeding within the community could challenge the validity of the ticket. Aspen Drive is approximately 1.7 miles in length from Log Tavern Road to Nelson Road, and includes at least four all way stop controlled intersections. There are currently two speed bumps provided along both approaches of Aspen Drive at its intersection with the northern leg of Ash Lane, which is an all way stop controlled intersection. A third speed bump is provided along the southern leg of the Aspen Drive at its intersection with Pitch Pine Lane, which is also an all way stop controlled intersection. Along Arrowood Drive, which is approximately 0.5 miles long, stop signs are provided at both ends of the road; however, there are no intersecting roadways where all way stop control could be provided. The two speed bumps are located approximately 200 feet apart, to the south of the Buckeye Road intersection beyond a horizontal curve. The speed bumps, which are used along both Aspen Drive and Arrowood Drive, are not typically utilized currently as they have been replaced with speed humps. Speed humps have a longer cross section, are typically less jarring for emergency vehicles, and have less of an impact of emergency response times. The picture below indicates the primary difference between the speed bumps, which the community is currently utilizing, and speed humps in terms of size. Speed humps are typically purchased from a manufacturer and include reflective markings to improve their visibility and are made of a rubber material. Most manufacturers make a type of speed hump that are relatively easy to install and remove for winter snow plow operations. Speed Hump versus Speed Bump
Mr. Gerry Condon July 15, 2011 Page 4 Speed Bump Effectiveness Automatic traffic recorder (ATR) counts were conducted over a typical four day period from Wednesday to Saturday to record daily traffic volumes and vehicle speeds near the existing speed bumps along Aspen Drive and Arrowood Drive. Table 1 provides a summary of the daily volume and 85 th percentile speeds in each direction of travel. The 85 th percentile speed is defined as the speed at which 85percent of the data set is traveling at or below, which is typically compared to the posted speed limit. Table 1 ATR Summary NB SB Location Description Volume (vpd) 85th Percentile Speed (mph) Volume (vpd) 85th Percentile Speed (mph) Arrowood Drive North of the northern speed bump 241 27 275 32 Between speed bumps 319 45 314 45 Aspen Drive South of N. Ash Lane, south of speed bump 323 40 399 42 As can be seen from the table, the 85 th percentile speeds along Arrowood Drive, to the north of the speed bumps, is the close to the posted speed limit of 25 miles per hour. However, this is likely a result of the horizontal curve in the roadway and not a function of the speeds bumps. As the 85 th percentile travel speeds in the area located between the two speed bumps along Arrowood Drive is 45 miles per hour, it is likely that the installation of the two speed bumps in this location is not having the desired effect on vehicle speeds. Similarly, along Aspen Drive, the 85 th percentile travel speeds are both at least 15 miles per hour over the posted speed limit of 25 miles per hour. Based upon the location of the ATR, if the speed bumps and stop signs at the Ash Lane intersection were operating effectively, then the travel speed in the southbound direction should have been much lower than documented. Speed Bump Usage The resultant speeds along Aspen Drive and Arrowood Drive near the speed bumps are indicative of typical driver patterns that have been documented in other traffic calming studies where allway stop control is provided. Past studies have indicated that drivers tend to increase their vehicle speeds in the mid block areas between all way stop controlled intersections in an attempt
Mr. Gerry Condon July 15, 2011 Page 5 to make up for perceived lost travel time. In addition, one study has also shown that the design of some speed bumps produce less discomfort at higher speeds than low speeds. The existing speed bumps along Aspen Drive and Arrowood Drive are not located at appropriate conditions, nor are they properly signed. If an accident were to occur near the speed bumps, the association could potentially be liable as there is a typical driver expectancy regarding visibility and signage for the speed bumps that is lacking within the community. An article entitled, Legal Aspects of Traffic Calming Devices by Reid Ewing notes that while the choice of traffic calming devices are at the discretion of the government and public, some courts have found the speed bump to be patently unsafe when applied to public streets and that their low design speeds could so delay emergency vehicles as to cause serious injury or loss of life. Although both Aspen Drive and Arrowood Drive are private roads, there are ways for nonresidents to enter the community, particularly from the north where there are no gates, that allows for public assess of these roads. Small school buses for special needs students do use both roadways along with emergency vehicles, and both of have voiced complaints regarding the visibility and impact of the speed bumps on the students, emergency apparatus, and reduced speeds needed to safely negotiate the speed bumps. Recommendations It is our recommendation that the existing speed bumps located along Aspen Drive and Arrowood Drive be removed. If the community is still interested in a traffic calming device to reduce vehicle speeds, we would be happy to discuss various options with the property owners association to develop a program that is acceptable to the community, which is an integral part of a successful traffic calming program. One recommendation for consideration is the use of removable speed humps or tables. Removable speed humps or tables are available from different manufacturers, and can be purchased with permanent reflective markings in yellow or white to improve their visibility. Furthermore, the rubber speed humps/tables can be removed for winter maintenance periods, which will not result in sections of the roadway being left unplowed. Depending on the manufacturer, the community may be able to temporarily install a speed hump to determine if they are effective, and to allow the emergency and school vehicles to test drive them, as well. Pennsylvania s Traffic Calming Handbook provides the following guidance on the use and placement of speed humps: Should be placed 250 to 600 feet apart; Should not be placed within 150 feet of an unsignalized intersection; Should not be installed on streets without curbing unless obstructions such as signing, flexible delineator posts or bollards prevent drivers from driving around the hump. Rocks, boulders, and other objects of this nature should not be used for this application; and
Mr. Gerry Condon July 15, 2011 Page 6 May require some type of measure, such as a flexible delineator post, in areas with snow removal problems to alert snow plow operators to lift their blades. With removable speed humps this would not be an issue. In addition, if the speed humps or tables are utilized, appropriate pavement markings and signage should also be provided to improve their visibility that would be in compliance with the Manual of Traffic Control Devices. Sign W17 1 should be placed prior to the speed humps or tables to notify vehicles of their presence. The graphic below illustrates the typical pavement markings that are recommended to delineate the location of the speed humps/tables which improve their visibility for motorists. Advance warning markings for speed humps.
Mr. Gerry Condon July 15, 2011 Page 7 Given the size of a typical speed hump and the distance needed to provide the advance warning pavement markings, each speed hump would require approximately 225 feet. As a result, the recommended center to center spacing for a series of speed humps should minimally be 550 feet. We could work with the property owners association to determine where the most appropriate locations would be for the speed humps, such as along long straight sections of roadway, where vehicle speeds could be expected to increase. If the speed humps are to be utilized throughout the community, then it would be beneficial to test a series of 2 to 3 speed humps along a select section of roadway to ensure that the desired operational benefits are achieved and that the impact on emergency vehicle response times and school bus operations are minimal prior to installing them throughout the community on other roadways. If you should have any questions, or require further information regarding setting up a formal traffic calming program for the community, please feel free to contact me or Ken O Brien, P.E.. We appreciate the opportunity to work with you. Sincerely, Sandy A. Koza, P.E., PTOE Project Manager SAK/ Attachments I:\eng\910696\Correspondence\Client\LetterReport.doc
ATTACHMENT Automatic Traffic Recorder Count Data