Speed Evaluation Saw Mill Drive Prepared for: Mount Laurel Township Burlington County, New Jersey Prepared by: Dana Litwornia Litwornia & Associates, Inc. Transportation, Traffic & Environmental Engineering P.O. Box 230 Medford Lakes, NJ 08055 1
Summary The primary purpose of this evaluation is to determine the proper speed limit for Saw Mill Drive. The secondary purpose is to provide the information to the municipality to forward to the DOT for speed limit modifications if required. In the spring of 2012 an evaluation of the maximum speed on Saw Mill Drive in Mount Laurel Township, Burlington County, NJ was evaluated. This evaluation was conducted to ensure the speed limit put into place in 2002 of 25 is meeting the needs of the community effectively. The speed in 2002 was put into place due to the number of residents filing complaints for speeding issues on Saw Mill Drive. This report will look into the current speed of traffic and traffic volume to ensure the efficiency of the posted speed limit on Saw Mill Drive. The staff at Litwornia & Associates, Inc. preformed this analysis. Litwornia and Associates is a private consulting firm that specializes in transportation, traffic & environmental engineering in Medford Lakes, NJ. Based upon the results of the evaluation which included visiting the site and gathering data on numerous occasions in March and April 2012, it was found that the community s needs were effectively being met by the current aped limit. The procedures that were used in the speed evaluation of Saw Mill Drive are as follows: Traffic volume surveys were completed on three occasions. The results showed the volume at the site as low, only one hour was thus needed for 50 cars to conduct the Spot Speed Study and Radar Speed Check. Radar Speed Check was completed finding the average speed of cars to be 26.3 to be rounded to 25 miles per hour. Implicating the current maximum speed of 25 mph as correct. In traffic engineering speed limits are rounded to the neatest 5 mph. Spot Speed Study was conducted the average speed found was 25.7 rounded to 25miles per hour. The 85 th percentile speed was found to be 25 miles per hour. Therefore the current maximum speed of 25 miles per hour has been found to be correct. It was determined through these field study analyses that the limit of 25 miles per hour is an appropriate speed for Saw Mill Drive. The entire length of the road should continue to hold its current maximum speed of 25miles per hour. Introduction Saw Mill Drives last speed evaluation was conducted by the Mount Laurel municipality in 2002 where in a speed limit of 25 miles per hour was enforced. Prior to this evaluation there was no posted speed limit. There are records of written complaints on file with the municipality. There is presently a posted speed of 25 miles per hour posted in three places on Saw Mill Drive. The purpose of this report is to ensure that the speed limit on Saw Mill Drive is appropriate and can be effectively enforced. This has been found to be a residential area on each of the visits to the site multiple children were observed playing in and around Saw Mill Drive. The purpose of this speed limit 2
evaluation was to determine if the current maximum speed of 25 miles per hour is an effective rate of travel on Saw Mill Drive as to ensure the safety of the residence. Traffic surveys were conducted on three occasions to find the maximum volume of vehicles within a given time. The counts were done in two hours intervals between the time of 6:30 8:30, recording at intervals of 15minutes. The results showed the volume of traffic on Mill Drive to be under 1,000 cars per hour equating the site as low volume area. Thus only one hour was needed to conduct the Radar Speed Check. The Radar Speed Check of 2002 was completed by Lieutenant Sheppard of the Mount Laurel Police Department on Saw Mill Drive between Wharton Road and Leighton Drive. This Mount Laurel Township. Lieutenant Sheppard survey found the average speed of cars to be 26.3 to be rounded to 25 miles per hour. The current Radar Speed Check was completed on March 21, 2012 this was conducted by Dana Litwornia. The results were similar as the average speed of traffic was 25.5 rounded to 25 miles per hour. Thus the current maximum speed is accurate. This was found by using the radar speed check numbers to find the 85 th percentile speed on Saw Mill Drive. The average speed found was 25.5 rounded to 25 miles per hour. The 85 th percentile speed was found to be 25 miles per hour. Therefore the current maximum speed of 25 miles per hour has been found correct. Spot Speed Study was done to measure the speed characteristics of Saw Mill Drive. This was done by following several random cars. This was done by remaining three seconds behind the vehicle being spot checked and documenting the rate of your own speed. This is a random test and in low traffic areas it only needs to be done for several vehicles. The product of the evaluation has been found through each of these specific studies. The weather on each day was also taken into consideration as weather may change the pattern of traffic on any given day. Each one of the studies were conducted on a sunny dry day. This is the best weather for conducting traffic surveys. It has been determined the proper speed has been in place since 2002 when the township implemented a maximum speed limit of 25 miles per hour. This information was based upon the engineering investigation of Saw Mill Drive including multiple field visits to the site. Description This evaluation will be used by Litwornia & Associates to evaluate the effectiveness of the speed that has been established. Saw Mill Drive is a Residential street that is a loop roadway off Elbow Lane. Saw Mill Drive is about 40 feet in width and approximately 2,485 feet in length. Saw Mill Drive has both curbs and sidewalks on both sides of the street. There are two T intersections on Saw Mill Drive both of which have a stop sign in place to control traffic. Saw Mill Drive is entirely within the Township; NJDOT approval is not required for any changes in speed that are necessary. The township will need to send in a report to the NJDOT that is certified. The certified report must come from a professional engineer. 3
When the report is given to the Township it will then be forwarded to the NJDOT for information. The NJDOT then approves the ordinance and forwards it to the township for implementation. Once this is completed the township will be able to install speed limit signs on Saw Mill Drive and enforce the posted speed limit. The following objectives of this evaluation pertain to the goal which is, correctness of the current maximum speed limit on Saw Mill Drive. The following list of objectives will help in gaining insight both quantitatively and qualitatively by seeing the larger picture: What is the 85 th percentile speed? What is the average volume of traffic? Is this a suburban or urban area? Is the current speed effective. Program Components Speed limits are decided differently in each state. There are different types of roads such as urban, residential and interstate highways. The maximum speed limit on urban roads in NJ is 25 mph. On rural roadways the speed is 50 mph and on the highways it can increase to 55 mph. This is based on the length and type of the road (urban or rural). School zones need to be evaluated in NJ, as the speed limits will drop during school hours. There is also the possibility that the speed may change temporarily during a period of construction changing the classification of work zone. To find the classification of the area evaluated the traffic volume must be recorded. The traffic counts are recorded by hand or machine as each car or truck passes a point entering an intersection. This is the sampling period. This period may last from one hour to a week this depends on the classification given by the municipality. In this study there were three traffic counts done finding that Saw Mill Drive had under 1,000 cars per hour traveling in any given direction therefore giving the site a low volume title. The results of the recordings will give an idea to the type of volume that the road has on a daily basis. This information is then used to gain a larger perspective of the site. The volume of traffic will determine how long the subsequent surveys will need to be conducted. Saw Mill Drive was determined to be a low volume area this requires a one hour radar speed check study. The remaining studies include the radar speed check done for one hour at the site. Checking speed by radar consists of using a radar gun to record speed of cars or trucks that pass by a point and the speed spot study. The speed spot study is simply following several cars and documenting their speed. This is found as the driver of the test car drives 3 to 5 seconds behind the car being studies and simply writes down the speed of the test car. In low volume areas this test needs only approximately ten sample cars to be effective. This test showed the majority of cars (5) going the approved speed of 25 mph. 4
In this instance the NJDOT will not have to approve any changes that may be needed. This is because in the state of NJ roads that fall entirely within the municipality and are not state or federal roads only need a certified evaluation of the site and findings. The findings go from the engineering firm to the municipality then to the NJDOT for the ordnance. Once this has been sent back to the municipality the speed limit changes may go into effect. Evaluation Method Participants Alexander Litwornia and Arnold Garonzick of Litwornia and Associates assisted in the administration of the surveys, equipment and training necessary for the use of the provided radar gun and road detector material such as count boards. This equipment was used for specific evaluation procedures. Dana Litwornia completed speed radar checks on March 21, 2012 on the west corner of Saw Mill drive. Litwornia and Associates provided the radar gun for this study. Each passing car/truck was speed checked from 7:30am 8:30 pm. The results showed the average speed to be 25.5 rounded to 26 miles per hour. The 85 th percentile speed was found to be 25 miles per hour. Therefore the current maximum speed of 25 miles per hour has been found correct. On March 28 th form 7:30am 8:30am Dana Litwornia completed the saw Mill Drive Spot Speed Study this was done by following ten random vehicles at the site. It was found that the average speed found was 25 miles per hour. Litwornia and Associates was selected for this evaluation due to my experience working with this firm. Working on field studies regularly has been my job. However, this is my first formal evaluation for the firm. The key mentor, and instructor for this evaluation was Mr. Alexander Litwornia. Mr. Litwornia has over 35 years of experience in traffic and transportation engineering. As a consultant, Mr. Litwornia has represented various clients including municipalities. Mr. Litwornia has performed various air quality, noise and traffic studies throughout the New York-New Jersey metropolitan area. Mr. Litwornia provided me with books, reports and all of the equipment and knowledge necessary to complete this evaluation. Other sources of information were provided to the firm by Mount Laurel Townships well as well as by the Mount Laurel PD. The information that was obtained consisted of a previous radar speed evaluation for the site in 2002 and several letters requesting the evaluation of the site. This was necessary for the re-evaluation to see if there were any significant changes in traffic patterns since the 25 mph limit was enforced. Procedures Five field studies were conducted to determine the amount of traffic volume in on Saw Mill Road. These studies consisted of one hour long radar speed check, one hour long spot speed check and 3 three hour traffic counts. Each of these surveys were conducted mid week during high traffic volume times. High volume times are known to fall between 6am 9am and 4pm 7pm. By conducting these studies during these 5
times our surveys will have the most reliable results. While at the site there were many children seen playing near the road. There were no other observations relevant to this survey as everything observed was normal. Data Sources The data sources used were the field studies completed for this evaluation. The field studies gave incite to the quantitative aspects of this report. For this evaluation there were several traffic counts conducted to find the volume of cars and trucks on Saw Mill Road. This was completed between 7am 9am. Count boards are used to keep track of the cars that pass by. The numbers are then recorded every fifteen minutes. The results show that Saw Mill Road is a low volume traffic area there fore requiring less time for speed checks. Next, radar speed checks were done between the time of 7:30am and 8:30am on March 21, 2012. A radar gun was the equipment that was needed to perform this observation the radar gun was available through Litwornia & Associates. Finally, speed spot checks were taken to obtain the average speeds of the vehicles are between the time of 7:30am and 8:30am on March 22, 2012. The results were used to help evaluate the speed limit. Results The overall goal of this evaluation is to determine whether or not the speed limit of 25 mph on Saw Mill Drive is the correct speed. Saw Mill Drive is a residential area that is home to children that play near the road. The site was found to be in a low traffic area. The surveys that were conducted to analyze the results for this speed were: radar speed checks, spot checks and traffic surveys. The surveys were used by the evaluator in finding the appropriate speed of 25 miles per hour. The surveys successfully found the mean speed by both radar as well as spot-checking. The low volume was found successfully as a result of the three traffic surveys conducted on three different days of the week for three consecutive hours during high traffic flow times. The result of these surveys confirm the previous evaluation of 2002 mandating the current 25 mph speed limit is not changed. Figure 1 shows the maximum numbers of vehicles from the traffic surveys found within nine hours of traffic surveys. The highest number of cars westbound during the count on Saw Mill Road was 47. The number of cars that were eastbound was 23.The number of trucks was three and busses were 6. There were less than 1,000 cars per hour at the site, thus confirming Saw Mill Road as a low traffic volume roadway. Figure 2 shows the results of the ten cars that were randomly used on March 22, 2012. for a spot check. There was 1 car found to be going at a rate of 15 miles per hour and 1 car found to be going at a rate of 30 miles per hour. There were 3 cars found to be moving at a rate of 20 miles per hour. The maximum amount of cars (5) were found to be driving at a rate of 25 mile per hour. This is the proper speed limit on Saw Mill Drive. 6
Figure 3 shows the results of the radar speed check. the results show the average speed to be between 25-30 miles per hour. The most cars (13) were found going between 25 and 30 miles per hour, closely behind that were the 12 cars traveling between 20 and 25 miles per hour. Figure 1 Number of Vehicles 50 40 30 20 10 Maximum Volume of Traffic 47 23 6 3 Eastbound Westbound Busses Trucks Figure 2 Number of Vehicles 5 0 Speed Spot Check Results 5.00 3.00 1.00 1.00 0-5 mph 10 15 20 25 30 35 45 0 Speed of Vehicles 7
Figure 3 Radar Speed Results Amount of Vehicles 7 9 12 13 3 2 2 1 1 0-5mph 10 15 20 25 30 35 40 45 50 0 Speed of Vehicles Discussion The purpose of this evaluation was to determine if the speed limit of Saw Mill Drive is effective. Speed is an important consideration in highway transportation because the rate of vehicle movement has significant economic, safety, time and service (comfort and convenience) meaning to both the motorist and the general public (Box & Oppenlander p 78). After personal investigation, personal field inspections and engineering studies Litwornia & Associates certifies that the speed of 25 miles per hour meets the previous ordnance put into place on Saw Mill Drive. Field studies were made to see of the traffic volume, and zoning for the statuary speed limit of 25 were met. Our findings through these studies were as follows. This is a residential area has a roadway that is 2,485 ft. long and the speed limit of 25 mph has been found effective. A speed survey was taken on March 21, 2012 on the west corner of Saw Mill drive by Dana Litwornia during the hours of 7:30am to 8:30am. During this time period 50 cars were observed. The speeds varied form a low of 5 mph to a high of 45mph. The 85th percentile speed was 25 miles per hour. A review of the speed data indicates that a speed limit of 25 miles per hour should be continued as previously decided. 8
References: Box, Paul C., and Joseph Oppenlander Ph.D.. Manuel of Traffic Engineering. Arlington : Institute of Transprotation Engineers, 1976. Print. 9
DANA LITWORNIA Invoice May 1, 2012 to: Dr. T! Speed Evaluation! Dana Litwornia! Trading Post Lane! Medford Lakes NJ project title: Speed Evaluation project description: Saw Mill Drive invoice number: 67890 term: 30 Days DESCRIPTION QUANTITY UNIT PRICE COST Field Studies 5 days $! 500.00 $! 2,500.00 Evaluation 9 days $! 500.00 $! 4,500.00 Expenses (travel) 5 days $! 30.00 $! 150.00 $! 0.00 $! 0.00 $! 0.00 $! 0.00 $! 0.00 Subtotal $! 7,150.00 Tax 8.25% $! 589.88 TOTAL $ 7,739.88 If you have any questions please do not hesitate to call. Sincerely yours, Dana C. Litwornia Dana Litwornia 10
APPENDICES LOCATION MAP FIELD DATA COMMUNITY INPUT GENERAL BACKGROUND INFORMATION ON SPEED LIMITS 11
LOCATION MAP 12
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FIELD DATA 15
Radar Speed Check 2002 16
Spot Speed Study 2002 17
AM Traffic Count 3/14/2012 Dana Litwornia 18
PM Traffic Count 3/14/2012 Dana Litwornia 19
PM Traffic Count 3/15/2012 Dana Litwornia 20
Radar Speed Check 7:30am to 8:30am 3/21/2012 Dana Litwornia 21
Spot Speed Study 7:30am to 8:30am 3/22/2012 Dana Litwornia 22
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Ordinance 2002 25
COMMUNITY INPUT 26
Letters form 2002 27
Letters form 2002 28
GENERAL BACKGROUND INFORMATION ON SPEED LIMITS 29
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