TRAFFIC STUDY Birch Bluff Road / Pleasant Avenue 01/15/2018 City of Tonka Bay 4901 Manitou Road Tonka Bay, MN 55331 WSB PROJECT NO. 10805-000
Birch Bluff Road/ Pleasant Avenue Traffic Study For: City of Tonka Bay 4901 Manitou Road Tonka Bay, MN 55331 January 15, 2018 Prepared By: WSB & Associates, Inc. 701 Xenia Ave. South, Suite 300 Minneapolis, MN, 55416 (763) 541-4800 (763) 541-1700 (Fax)
Table of Contents Certification... 1 Introduction / Background... 2 Existing Traffic Characteristics... 4 Identified Issues... 11 Improvement Opportunities... 13 Issue Analysis / Conclusions... 15 Recommendations... 17 Figures / Tables Figure 1 - Location / Study Area... 3 Figure 2 Daily Traffic Volumes... 5 Figure 3 85 th Percentile Vehicle Speeds... 8 Figure 4 Crash History... 9 Figure 5 Existing Traffic Control... 10 Figure 6 Recommended Improvements... 18 Table 1 Traffic Volume and Speed Data per Day... 4 Table 2 Crash Summary by Year... 7 Table 3 Crash Summary by Type... 7 WSB PROJECT NO. 10805-000 PAGE i
Certification I hereby certify that this plan, specification or report was prepared by me or under my direct supervision and that I am a duly registered professional engineer under the laws of the State of Minnesota. Charles T. Rickart, P.E. Date: January 15, 2018 Reg. No. 26082 WSB PROJECT NO. 10805-000 PAGE 1
Introduction / Background Tonka Bay residents along Birch Bluff Road and Pleasant Avenue have raised concerns with the speed, volume of traffic and safety on these roadways. This has been a concern for several years. Most recently, in April 2017, a presentation was made to the Tonka Bay City Council by several residents outlining traffic information collected with recommendations to improve the conditions on these streets. As a result, the Tonka Bay City Council requested a Traffic Study be prepared to evaluate the existing traffic conditions and recommend possible low impact, low cost improvements for the Birch Bluff Road/Pleasant Avenue area. In order to prepare a study that addresses the City of Tonka Bay residents concerns WSB collected updated traffic data, and; identified and evaluated alternative traffic improvements/measures to improve the safety and operation on the area streets. The evaluation process focused on determining if and where traffic issues exist and if they could be improved or eliminated by the application of alternative traffic improvements. The Minnesota Manual on Uniform Traffic Control Devices (MnMUTCD); Minnesota Department of Transportation (MnDOT) Design and Traffic Engineering Manuals; and traffic engineering standard practices and principal were used as the basis for the evaluation process. The steps in the process included: 1. Documenting that a problem exists such as excessive speeds or crashes 2. Determine the frequency or recurring nature of the problem and that it is not a random or isolated event. 3. Identifying potential measures that would improve or eliminate the problem. This includes intersection controls and/or addressing other conditions at the problem locations Any recommendations for changes in the Birch Bluff Road/Pleasant Avenue have been developed keeping the following goals in mind: Improvement to safety. Application of least restrictive control type possible. Traffic control consistency within the area. Would not promote cut-through or diversion of traffic to other streets in the area. Would not promote speeding on streets within the area. The Birch Bluff Road/Pleasant Avenue area for the purposes of this study is bounded by Birch Bluff Road on the north, Pleasant Avenue on the south, Eureka Road on the west and CSAH 19 on the east. The Project Location including the study area is shown in Figure 1. The following sections of this report document the existing traffic data collected, analysis of the data, improvement alternatives and recommended improvements. WSB PROJECT NO. 10805-000 PAGE 2
WSB PROJECT NO. 10805-000 PAGE 3
Date Existing Traffic Characteristics In order to evaluate the current safety and operational conditions in the Birch Bluff Road/Pleasant Avenue area, the existing traffic characteristics were collected. This included: Daily traffic volumes Crash history Vehicle speeds Current traffic control (signing, pavement markings, sidewalks, etc.). Traffic Volumes Daily traffic volumes were collected at three locations within the area for a two-week period from September 19, 2017 to October 2, 2017. The counts were conducted when school was in session to assure a worst-case condition. In general, the counts show that the volumes in the area are at those of typical residential neighborhood streets. Typical residential streets will have traffic volumes between 500 and 1000 vehicles per day(vpd). Table 1 shows a summary of the traffic volume data for each day. Figure 2 shows the Average Daily Traffic (ADT) volumes for an average weekday and weekend in the Birch Bluff Road/Pleasant Avenue area. Table 1: Traffic Volume and Speed Data per Day ADT Birch Bluff Rd - East of Eureka Rd Birch Bluff Rd - West of CSAH 19 Pleasant Ave - East of Birch Bluff Rd 85% Speed 20 mph and Above Greater than 30 mph ADT 85% Speed 20 mph and Above Greater than 30 mph ADT 85% Speed 20 mph and Above Tuesday Sept 19 889 30.1 794 138 644 30.4 577 103 463 29.0 409 89 Wednesday Sept 20 967 28.7 876 84 632 30.3 570 105 495 32.0 417 87 Thursday Sept 21 964 30.1 873 146 663 31.2 595 142 547 31.3 481 105 Friday Sept 22 1020 30.3 914 169 678 30.5 602 118 603 31.1 571 124 Saturday Sept 23 790 30.4 716 132 530 30.6 473 110 456 31.2 388 102 Sunday Sept 24 613 30.8 562 113 448 28.0 335 46 326 30.0 270 59 Monday Sept 25 830 29.3 610 78 548 29.8 476 75 444 30.5 358 76 Tuesday Sept 26 807 30.0 743 120 586 29.8 514 82 403 30.7 349 72 Wednesday Sept 27 891 29.8 799 128 622 29.6 561 89 500 30.7 442 93 Thursday Sept 28 920 30.3 848 149 624 30.4 553 104 519 Friday Sept 29 888 29.7 815 140 598 30.0 525 88 509 Saturday Sept 30 767 30.2 711 121 500 31.1 450 112 388 Sunday Oct 1 512 31.0 467 100 345 30.0 304 61 294 Monday Oct 2 805 29.6 663 116 562 29.2 499 65 459 Average Weekday 898 29.8 794 127 616 30.1 547 97 494 30.8 432 92 Average Weekend 671 30.6 614 117 456 29.9 391 82 366 30.6 329 81 Greater than 30 mph WSB PROJECT NO. 10805-000 PAGE 4
WSB PROJECT NO. 10805-000 PAGE 5
Vehicle Speeds In conjunction with the daily traffic counts, vehicle speeds were also collected. Vehicle speed data is typically given as the 85% speed. The 85% speed represents the speed at which 85% percent of the counted vehicles are traveling at or below. Research indicates that this value is where most drivers will operate their vehicle in a reasonable manor. The posted speed limit on the area roadways is 20 mph. While this is the statutory speed limit on these streets, the typical speed limit on most residential streets is 30mph. The data indicates that the majority of the vehicles are traveling at or above the posted speed but close to what a typical residential street would experience. Table 1 shows a summary of the speed results per day. Figure 3 shows the average 85% vehicle speed for the average weekday and weekend on the streets within the Birch Bluff Road/Pleasant Avenue area. It should be noted that in response to the speeding concerns the police have provided increased enforcement in the area over the past 18 months. Crash History Using the State of Minnesota Crash Mapping Analysis Tool (CMAT), crash data from the past 5 years (2011-2015) was documented. The data shows that over the past five years the only location that has more than one crash is at the intersection of Pleasant Avenue and CSAH 19. Of the eight crashes reported in the past five years, seven (6 northbound and 1 southbound) were rear-end crashes and one right-angle crash with a northbound vehicle turning in front of a southbound vehicle. Table 2 show the crash data by year for each location. Table 3 shows the type of crash by location. Figure 4 shows the location of the crashes from 2011-2015 in the Birch Bluff Road/Pleasant Avenue area. Existing Conditions/Traffic Control Devices The existing street width on both Birch Bluff Road and Pleasant Avenue ranges from 20ft to 22ft. The streets in most cases have vegetation/trees close to the edge of the road. Some street lighting is provided on Birch Bluff Road and Pleasant Avenue. The traffic control was also documented within the study area. This included location of: warning signs, stop signs, speed limit signs, pedestrian crosswalks and sidewalks. Figure 5 shows the existing conditions including street light locations and traffic control devices in the Birch Bluff Road/Pleasant Avenue area. WSB PROJECT NO. 10805-000 PAGE 6
Table 2: Crash Summary by Year Crashes Location Birch Bluff Road West of CSAH 19 Pleasant Avenue East of Birch Bluff Road Pleasant Avenue at Pleasant Lane CSAH 19 at Pleasant Avenue CSAH 19 at Woodlawn Avenue CSAH 19 North of Crabapple Lane CSAH 19 South of Birch Bluff Road PD = Property Damage PI = Personal Injury 2011 2012 2013 2014 2015 PD PI PD PI PD PI PD PI PD PI Total Crashes 1 0 0 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0 0 1 0 0 0 2 3 0 0 0 3 0 8 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 1 1 0 0 0 0 0 0 0 0 0 1 Table 3: Crash Summary by Type Location Birch Bluff Road West of CSAH 19 Pleasant Avenue East of Birch Bluff Road Pleasant Avenue at Pleasant Lane CSAH 19 at Pleasant Avenue CSAH 19 at Woodlawn Avenue CSAH 19 North of Crabapple Lane CSAH 19 South of Birch Bluff Road Type Sideswipe Ran off Road Rear End Right Angle Total Crashes 1 0 0 0 1 0 1 0 0 1 0 0 1 0 1 0 0 7 1 8 0 1 0 0 1 0 1 0 0 1 0 1 0 0 1 WSB PROJECT NO. 10805-000 PAGE 7
WSB PROJECT NO. 10805-000 PAGE 8
WSB PROJECT NO. 10805-000 PAGE 9
WSB PROJECT NO. 10805-000 PAGE 10
Identified Issues Issues were identified based on two primary sources including neighborhood input and the data collected. In most instances, the input from the neighborhood was validated by the data collection. Neighborhood Input/Comments Issues and concerns identified by the neighborhood included: 1. Residents/Children near street 2. Pedestrian and bicycle traffic 3. Vehicle traffic volumes 4. Speeding 5. Intersection of Pleasant Avenue at CSAH 19 6. Adjacent development (cut-through traffic) 7. Street configuration (width) 8. Emergency vehicle access Issues Identified Based on Data Based on the data collected three primary issues were reviewed including, safety, speed and cut-through traffic. In order to determine the magnitude of the issues and the level of improvements needed, screening criteria was developed. Safety The safety of an intersection or roadway segment is defined by the number, frequency and type of crashes at a location. An intersection or roadway segment is not considered to have a safety issue if there have only been one or two crashes during any multiyear analysis period. However, if there have been more than two crashes the following criteria should be used to trigger further study of an intersection or roadway segment. One (1) crash per year for three or more years, or More than three (3) crashes in one year. Based on these criteria the only location in the study area that was identified for additional study is the intersection of Pleasant Avenue and CSAH 19 with 8 reported crashes. All other intersections or roadway segments had two crashes or less in the 5-year period. Speed The 85% speed is used as the primary measure of the speed on a segment of street. If the 85% speed is greater than the posted (20mph) speed limit then the street segment should be further studied. Based on this criterion both the Birch Bluff Road and Pleasant Avenue roadway segments have an 85% speed greater than 20 mph. 1. Birch Bluff Road, east of Eureka Road 29.8mph/30.6mph 2. Birch Bluff Road, west of CSAH 19 30.1mph/29.9mph 3. Pleasant Avenue, east of Birch Bluff Road 30.8mph/30.6mph WSB PROJECT NO. 10805-000 PAGE 11
Cut-Through Traffic The potential for cut-through traffic was evaluated for the Birch Bluff Road/Pleasant Avenue area. The study area is fairly captive with a limited number of street accesses in and out. Based on a review of the area there are approximately 135 homes in the area between Grant Lorenz Road and the intersection of Pleasant Avenue at Birch Bluff Road that could use Birch Bluff Road and/or Pleasant Avenue to or from CSAH 19. In addition, there are 35 homes on Birch Bluff Road and 40 homes on or adjacent to Pleasant Avenue. By using standard Institute of Transportation (ITE) trip generation factors for residential homes the number of estimated daily trips that could use Birch Bluff Road and/or Pleasant Avenue was determined to be approximately 2,000 vehicles per day (vpd). Comparing this the existing traffic count on the adjacent streets in and out of the area, it can be concluded that the level of traffic entering or exiting the area does not indicate a cut-through issue. Along with the traffic data review, a travel time analysis was also conducted. This analysis evaluated two routes, one using the primary collector street system and one traveling through the Birch Bluff Road/Pleasant Avenue area. For both routes the beginning and ending points were the same, starting on Smithtown Road at Eureka Road and ending on CSAH 19 at Birch Bluff Road. The primary collector street route followed Smithtown Road to CSAH 19 to the intersection with Birch Bluff Road. The neighborhood route followed Eureka Road to Birch Bluff Road to CSAH 19. Several travel time runs during AM and PM peak hours and off-peak hours were made along both routes, calculating the time it took from beginning to end. Based on the travel time calculations it was found that it would take approximately an additional two minutes to travel through the neighborhood, not following the primary collector route along Smithtown Road to CSAH 19. WSB PROJECT NO. 10805-000 PAGE 12
Improvement Opportunities For each of the identified issues there are several low cost, low impact improvement opportunities that could be implemented depending on further analysis of the conditions and data. Discussed below are some of the possible improvement opportunities and the criteria for implementations. Safety Improvements Safety improvements include items that could provide potential benefits by reducing the number of crashes. These improvements would include: 1. Removing obstructions When the analysis indicates that a sight line issue is present at an intersection; where possible the sight line triangle should be cleared of obstructions. Based on a typical 25mph/30 mph city street the sight triangle is a distance between 30 and 50 (depending on right of way width) measured along the right of way line at the intersection. This distance should be based on calculations from the AASHTO A Policy on Geometric Design of Highways and Streets Green Book. If clearing the obstruction is not possible, further consideration to other intersection control should be explored. 2. Advance warning signs Advance warning signs could include Stop Ahead, Intersection Ahead, etc. These signs would be installed where intersection control is typically in place and/or crashes indicate that sight lines to the intersection may be an issue. 3. Blinker signs Blinker signs are typically used where vehicles need additional warning or in extreme cases with limited sight distance and higher traffic volumes. They can be used on either warning signs (advanced signs) or regulatory signs (stop or yield signs). 4. Pavement markings This could include either center line or edge line markings. They would typically be used where crashes indicate issues with vehicles staying in their own lane. 5. Lighting Intersection lighting could be used to clearly locate an intersection at night. Typically, lighting could be installed where there are a significant number of crashes occurring at night. WSB PROJECT NO. 10805-000 PAGE 13
6. Yield signs Yield signs are typically used in locations where there is confusion on which vehicle approaching the intersection has the right of way. These signs can be used to help clearly assign the right-of-way at an intersection with a balanced traffic flow on all approaches. 7. Stop signs The Minnesota Manual on Uniform Traffic Control Devices outlines warrants for the installation of stop signs. These warrants include criteria for installation of both all-way or 2-way stops. In addition, stop signs could be considered where sight distance cannot be improved. 8. Turn Lanes/By-Pass Lanes The Minnesota Department of Transportation (MnDOT) Road Design Manual and Local Road Research Board have established criteria for the addition of turn lanes or by-pass lanes based on traffic volumes and crash data. Specifically, the number of turning vehicles vs opposing vehicles and/or rear-end type crashes. Speed Reduction Improvements Speed improvements include items that would provide potential benefits by reducing speeding in the neighborhood. These improvements could include: 1. Speed limit signs In locations where the ADT volume is over 750 vehicles per day and there is currently not a posted speed limit sign and the 85% speed is over the posted speed limit, consideration should be given to installing speed limit signs. 2. Driver feed-back (dynamic) speed signs Driver feed-back signs are signs that display the actual speed of a vehicle as it drives by the location. On neighborhood streets where the 85% speed is determined to be greater than 3mph above the posted speed limit, a driver feed-back sign could be used to warn the driver that they are speeding. 3. Additional enforcement Based on the traffic speed data collected if the 85% speed is up to 3mph over the posted speed limit, consideration should be given to requesting additional police enforcement. This improvement opportunity has been implemented by the police over the past 18 months. WSB PROJECT NO. 10805-000 PAGE 14
Issue Analysis/Conclusions Based on the identified issues and the criteria discussed above for each improvement opportunity, the following analysis conclusions were made: The intersection of Pleasant Avenue at CSAH 19: The traffic volumes on Pleasant Avenue are not at a level to meet all-way stop or traffic signal installation warrants. The majority of the intersection crashes are northbound CSAH 19 rear-end type. There are no other trends with the crashes such as time of day or day or week or time of year. Based on the number of vehicles on CSAH 19 and with the type and number of crashes a northbound CSAH 19 by-pass lane would be warranted. Speeding Issues: As indicated by the neighborhood concerns and verified with the collected data, the speed of traffic in the area has an 85% speed over the posted 20mph limit. The following should also be considered in evaluating the speeding issue in Birch Bluff Road/Pleasant Avenue area: o Based on the traffic volume review it was documented that most of the traffic on these streets is local to the neighborhood. These should be people that know the area and what the speed limit and road conditions are. o While 20mph is the statutory speed limit on these streets, the typical speed limit on most residential streets is 30mph, which most people are used to driving. Based on the review of the alternatives available there are two improvements that could be considered. 1. Additional enforcement As indicated the police have implemented additional regular enforcement in the area over the past 18 months. 2. Driver feed-back signs Research has shown that installation of driver feedback signs can reduce the 85 th speed by up to 3mph. Although this would not reduce the speed to the existing posted limit it would provide a safety improvement with the reduction. Pedestrian/Bicycle Traffic: Although pedestrian data was not collected, there are not many options to improve the pedestrian/bicycle accommodations. The two primary options would be to widen the roadway added a shoulder or providing an off-road trail. Both options would impact the adjacent roadway right-of-way and have a high cost to implement. While the cost for adding a shoulder would be less, studies have shown that with wider street sections the speed of traffic could increase. Therefore, should an alternative be considered in the future and to maintain the lower speed on the streets, an off-road trail would be recommended. The 2009-2030 Tonka Bay Comprehensive Plan shows a proposed local trail adjacent to Pleasant Avenue and on Birch Lake Road from Pleasant Road to Crescant Beach. WSB PROJECT NO. 10805-000 PAGE 15
Cut-Through Traffic: As discussed in the issues identification section most of the traffic in the Birch Bluff Road/Pleasant Avenue area is local from the neighborhood. One of the alternatives proposed by the Tonka Bay residents is to reduce or restrict access to the area. While this would reduce traffic on the street that has the restricted access, it would increase traffic on other adjacent streets. Therefore, no improvements to restrict traffic should be considered. However, the traffic should to be monitored as the development of the area continues. WSB PROJECT NO. 10805-000 PAGE 16
Recommendations Based on the issues analysis and the analysis conclusions, the following low impact, low cost improvements are recommended for the Birch Bluff Road/Pleasant Avenue area. Figure 6 shows the location for the proposed improvements. Safety Improvements Install a northbound by-pass lane on CSAH 19 at Pleasant Avenue. Coordinate the improvement with Hennepin County. Speed Improvements Install new Driver feed-back signs in both directions at the following locations: a. Birch Bluff Road west of CSAH 19 b. Pleasant Avenue east of Birch Bluff Road Pedestrian Improvements Construct a future off-road trail adjacent to Pleasant Avenue and Birch Bluff Road as outlined in the Comprehensive Plan. Cut-Through Traffic Continue to monitor the traffic on Birch Bluff Road and Pleasant Avenue as development in the area continues. WSB PROJECT NO. 10805-000 PAGE 17
WSB PROJECT NO. 10805-000 PAGE 18