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HomeMy WebLinkAbout2005-10-03; Traffic Safety Commission; ; Establish an all-way stop on Hosp Way at the intersection of Wintergreen Drive/Grove Ave( ( CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: October 3, 2005 ITEMNO. 6B LOCATION: INITIATED BY: Hosp Way at the intersection of Wintergreen Drive/Grove Avenue Wanda Wood, 2952 Wintergreen Drive, Carlsbad, CA 92008 REQUESTED ACTION: Establish an all-way stop on Hosp Way at the intersection of Wintergreen Drive/Grove A venue BACKGROUND: Wanda Wood expressed her concern via letter regarding the lack of sight distance for drivers accessing Hosp Way from Wintergreen Drive, the speed of vehicles on Hosp Way in the vicinity of subject intersection, and the potential for traffic collisions due to the aforementioned concerns. She specifically requested that an all-way stop be established at Hosp Way and Wintergreen Drive/Grove Avenue (see Exhibit 1). Staff conducted traffic studies at the subject intersection in June 2005. The studies conducted by staff did not support the installation of an all-way stop on Hosp Way at Wintergreen Drive/Grove A venue. A letter was sent to Ms. Wood denying her request. A second letter was received from Ms. Wood asking that this matter be scheduled for a future Traffic Safety Commission meeting. DATA: Existing Conditions Hosp Way is an unclassified public street in the northwest quadrant of the City that functions as a collector street. It intersects Monroe Street on the west and follows a curvilinear alignment easterly until it terminates at El Camino Real. Hosp Way is a two-lane roadway and has curb/gutter and sidewalks on both sides of the street. Traffic control on Hosp Way is currently provided by a traffic signal at El Camino Real and an existing all-way stop at Forest View Way. Wintergreen Drive is a public street and is controlled by a stop sign at Hosp Way. Grove Avenue is a private street and is also controlled by a stop sign at Hosp Way. The centerlines of Wintergreen Drive and Grove A venue are offset by approximately 23 feet. The horizontal alignment for Hosp Way is curvilinear throughout its alignment. The roadway centerline has a radius of 310 feet to the north of and through the intersection of Wintergreen Drive/Grove Avenue, which meets the Engineering Department standard design criteria for a collector street for horizontal curvature. The roadway centerline has a radius of 500 feet to the immediate south of the intersection. Due to the curvilinear geometrics of the roadway, a series of curve warning signs are posted in each direction, each having an advisory plate of 25 MPH below it. ( ( CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: October 3, 2005 ( continued) ITEMNO. 6B The vertical alignment of Hosp Way varies from 1.86% to 11.0% throughout its alignment, with a centerline slope of 4.0% at the intersection of Wintergreen Drive/Grove Avenue. Hosp Way has a posted speed limit of 30 miles per hour. A speed survey conducted on April 12, 2000 found a critical or 85 th percentile speed, of 35 miles per hour at a location 300 feet west of A venida Magnifica. The critical speed is the speed at which 85% of the vehicles are traveling at or below. Midblock traffic counts were conducted on Hosp Way over a 24-hour period on June 4, 2003. The traffic volumes obtained are indicated on Table A. TABLE A HOSP WAY TRAFFIC VOLUMES June 4 2003 LOCATION Between Forest View Way and Winter reen Drive , VOLlJME BY DlREC'I.\JtON 1,004 1,178 TOTAL24- The design volume for a collector street ranges from 1,200 to 10,000 vehicles per day as referenced in the Carlsbad Engineering Standards for roadway design. From the traffic volumes indicated in Table A, it can be observed that for this segment of Hosp Way the traffic volumes are on the low end of the volume range expected for a collector street. Stop Sign Criteria Regulatory signs are used to inform road users of selected traffic laws or regulations. Stop signs are official regulatory signs and are installed where the regulation applies. The primary purpose of a stop sign is to assign right-of-way to drivers as they approach an intersection. Stop signs are not intended as a means for reducing speed. In general, they are installed in a manner that will minimize the number of vehicles having to stop and to provide for acceptable intersection operations. Criteria have been formulated for use in the evaluation of need for an all-way stop sign location. The Carlsbad Engineering Department follows the criteria and guidelines established by the Manual on Uniform Traffic Control Devices (MUTCD) as amended by ·the MUTCD 2003 California Supplement. One of the arguments against the use of unneeded stop signs is the concept of traffic control device uniformity. A stop sign used at an intersection where a full stop is vitally needed to prevent right angle collisions should not be considered at locations where drivers are not faced with any unusual or unexpected conflicts. The collision history of an intersection should be examined carefully as unwarranted stop signs do not necessarily prevent collisions. In fact, certain types of accidents such as rear-end collisions may increase at locations having a stop sign that is unnecessary. ( CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: October 3, 2005 ITEMNO. 6B (continued) Unwarranted stop signs create a substantial inconvenience for the motorist. For example, at the intersection of a heavily traveled street and a street with substantially less volume, the length of time overall vehicles must wait increases. A significant delay results to the large number of drivers on the major road while minimal delay is experienced on the side street. Another argument against unwarranted stop signs is the concern that if a stop sign seems to imply a nuisance regulation, observance of this regulatory device deteriorates and safety at intersections where the stop sign must be complied with can become compromised. Drivers have a tendency to ignore unwarranted stop signs. The behavior includes rolling through or running the stop sign. A lowered level of compliance leaves other drivers and pedestrians vulnerable to these vehicles. Other consequences of unwarranted stop signs include the increase in air pollution and noise pollution associated with vehicles decelerating to a stop unnecessaiily, idling, and then accelerating from the stop. When queues build up on an approach to an intersection, vehicles have to move up in the queue one car length at a time. Vehicle emissions and fuel consumption increase with the queue length. All-way stop signs placed on arterial roads at the intersection of a minor cross street can cause queues to build up quickly on the arterial, resulting in the negative environmental consequences mentioned above. The MUTCD as amended by the MUTCD 2003 California Supplement indicates that an all-way stop should ordinarily be used only where the volume of traffic on intersecting roads is approximately equal. The criteria for an all-way stop as provided in the MUTCD as amended by the MUTCD 2003 California Supplement are: A. Where traffic control signals are justified, 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. A crash problem, as indicated by five or more reported accidents within a 12- month period that are susceptible of correction by a multiway stop installation. Such crashes include right-tum and left-tum collisions as well as right-angle collisions. C. Minimum traffic volumes (All parts C.1, C.2a and C.2b must be satisfied); C. l The total vehicular volume from the major street must average at least 300 vehicles per hour for any 8 hours of an average day, and C.2a The combined vehicular and pedestrian volume from the minor street or highway must average at least 200 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 maximum hour, but C.2b When the 85 th percentile approach speed exceeds 40 MPH, the minimum vehicular volume warrant is 70% of the above requirements. ( ' ( CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: October 3, 2005 ( continued) Stop Sign Criteria Analysis ITEMNO. 6B Staff conducted an all-way stop analysis for the subject intersection. The criteria forms are attached. The three criteria as contained in the MUTCD as amended by the MUTCD 2003 California Supplement can be summarized as follows: Criteria A -Interim Traffic Control Measure Criteria B -Accident Experience Criteria C -Minimum Traffic Volumes The results of the criteria analysis are summarized in Table B. TABLEB STOP SIGN CRITERIA ANALYSIS RESULTS CRITERIA MET? INTERSECTION A B Hos No No Accident Analysis The all-way stop criteria analysis considers the number of collisions that have been reported in a 12-month period at an intersection of the type susceptible to correction by an all-way stop, such as right and left-tum accidents, as well as right-angle collisions; Staff researched the four-year collision occurrence history of reported collisions at the subject intersection to determine if there has been a past collision pattern. There have been no reported intersection collisions. However, there have been two reported collisions near the subject intersection during this four-year period as shown in Table C and as indicated on the attached collision diagram. TABLEC REPORTED TRAFFIC COLLISION HISTORY JANUARY 1, 2001 THROUGH DECEMBER 31, 2004 PRIMARY LOCATION ])ATE COLLISION FACTOR RESULT. 60' e/o Grove 1/26/03 Exceeding Safe Speed/Inattention Property Avenue Damage Only 25' w/o Grove 2/22/04 Exceeding Safe Speed Property Avenue Damage Only Both incidents involved a single vehicle that ran off the roadway and the accidents were not of type susceptible to correction by an all-way stop. ( ( CITY OF CARLSBAD TRAFFIC SAFETY COLLISION STAFF REPORT COMMISSION MEETING OF: October 3, 2005 ( continued) ITEMNO. 6B A collision can occur at any time and at any location for a variety of reasons. However, an examination of the collision history for those collisions for which a police report has been taken can reveal a pattern that may be corrected by installation of a stop sign. Based on the collision history, this intersection is not considered to be a "high accident" location based upon the collision data. Intersection Traffic Volumes The 24-hour approach volumes for each leg of the intersection were obtained in April 2005. The hourly volume by intersection over the 24-hour period is attached. A summary of each intersection approach volume is indicated in Table D. TABLED 24-HOUR INTERSECTION APPROACH VOLUMES An all-way stop is generally considered if the approach volumes on each leg of the intersection are approximately equal. From a review of Table D, it can be observed that the side street traffic volume is substantially less than the through volume of the major road, Hosp Way. Corner Sight Distance Sight distance is the length of road that is visible to the driver. Corner sight distance is provided at intersections to allow drivers of a vehicle stopped on the minor street to view approaching vehicles on the intersecting road and decide when to enter or cross the intersection. It is desirable that the available sight distance for the driver of a vehicle on the side street that is attempting to enter or cross the intersection to be at least equal to the appropriate stopping sight distance for the major road. If so, drivers generally have sufficient sight distance to anticipate conflicts and avoid a collision. In the case of sufficient stopping sight distance, the driver of a vehicle on the major road may be required to stop or slow to allow the maneuver of the minor street vehicle. Intersection operations are enhanced when corner sight distance exceeds the stopping sight distance along the major road. In the Caltrans Highway Design Manual, the corner sight distance value necessary for the design speed of 30 miles per hour on a collector street is given as 350 feet (corner sight distance required for 35 mph is 402 feet). Staff conducted measurements of the existing corner sight distance that is available for drivers on the side streets to view an approaching vehicle. ( \ ( CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: October 3, 2005 ( continued) ITEMNO. 6B The driver position was asswned to be 9.8 feet behind the prolongation of the curb line with the front of the vehicle positioned at the curb prolongation. A driver is expected to move forward to increase the corner sight distance before departing the intersection if there is a limitation due to vegetation or the roadway curvature. Corner sight distance measurements for each intersection are indicated on Table E. TABLEE HOSP WAY AND WINTERGREEN DR/GROVE A VE INTERSECTION CORNER SIGHT DISTANCE MEASUREMENTS Wintergreen Drive Grove A venue Stopping Sight Distance When the measured corner sight distance is less than the minimwn design standard, it may be attributed to obstructions on private property such as walls, homes, trees, vegetation, etc. The Caltrans Highway Design Manual recognizes that the cost to achieve the corner sight distance may be excessive. The manual states that the high costs may be attributable to the need to acquire additional right-of-way, building removal, extensive excavation, or unrnitigable environmental impacts. In these restrictive conditions, the manual states that a lesser value of corner sight distance may be used when the existing value for corner sight distance is equal to the stopping sight distance. For a 30 mile per hour design speed, the stopping sight distance required is 200 feet (stopping sight distance required for 35 mph is 255 feet) . The minimum stopping sight distance is the distance required by the driver on the major road for the given speed to bring the vehicle to a stop after observing an object in the road. The stopping sight distance, in concept, provides sufficient distance for the majority of drivers to control the vehicle and safely stop to avoid collision with the object in the road. It is measured from the driver's eyes, assumed to be 42 inches above the pavement surface, to an object 6 inches high on the roadway. Available stopping sight distance at the subject intersection was measured to be 290 feet for an approaching eastbound vehicle and 220 feet for an approaching westbound vehicle. Conclusion For the evaluated intersection, warrants are not met to establish an all-way stop. There have been no reported collisions in the past four years of the type that would be susceptible to correction by the installation of an all-way stop. The minimum corner sight distance is met for westerly direction from Wintergreen Drive and the easterly direction from Grove A venue. The minimwn stopping sight distance is satisfied for both directions for the design speed and posted speed limit of 30 miles per hour. ( CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: October 3, 2005 (continued) RECOMMENDATION: ITEMNO. 6B It is the recommendation of the Traffic Safety Coordinating Committee that an all-way stop not be established at Hosp Way and Wintergreen Drive/Grove Avenue. NECESSARY CITY COUNCIL ACTION: No City Council action required unless an all-way stop 1s recommended to be implemented. LOCATION MAP ~~ TERSECTION 6lB NOT TO SCALE g I A !Ji 17A Los cJ 5Afiros LEGEND @ Existing Traffic Signal @ Existing All-Way STOP ti i { ! ! ----------------------------------------1"§ REQUEST FOR ALL-WAY STOP AT Exhibit HOSP WAY & WINTERGREEN DRIVE/GROVE AVENUE 1 ------------------------------------- !! ~ ] ~ it ! INTERSECTION: COUNT DATE: Major Street Hosp Way Time Eastbound 0000-0100 14 0100-0200 3 0200-0300 2 0300-0400 2 0400-0500 1 0500-0600 5 0600-0700 13 0700-0800 38 0800-0900 53 0900-1000 24 1000-1100 32 1100-1200 55 1200-1300 32 1300-1400 41 1400-1500 83 1500-1600 65 1600-1700 100 1700-1800 109 1800-1900 84 1900-2000 75 2000-2100 73 2100-2200 48 2200-2300 35 2300-2400 28 Column Totals 1015 Recorded by: John T. Kim Date: 04/20/2005 24-HOUR APPROACH COUNT SUMMARY SHEET Hosp Way and Wintergreen Drive/Grove Avenue April 19, 2005 • Minor Street Total Wintergreen Drive/Grove Avenue Intersection Major Street Minor Street Approach Westbound Subtotal Northbound Southbound Subtotal Volume 7 21 5 1 6 27 0 3 0 0 0 3 3 5 0 0 0 5 3 5 3 0 3 8 4 5 5 0 5 10 15 20 4 1 5 25 58 71 4 3 7 78 110 148 19 7 26 174 74 127 12 10 22 149 73 97 15 7 22 119 54 86 12 8 20 106 60 115 8 5 13 128 52 84 8 7 15 99 70 111 13 5 18 129 84 167 20 2 22 189 77 142 20 13 33 175 96 196 17 7 24 220 98 207 13 4 17 224 65 149 10 3 13 162 68 143 5 3 8 151 43 116 7 0 7 123 41 89 4 0 4 93 22 57 9 1 10 67 10 38 7 2 9 47 1187 2202 220 89 309 2511 TRAFFIC COLLISION DIAGRAM CITY OF CARLSBAD TRANSPORTATION DIVISION LOCATION: MIDBLOCK COLLISIONS ON HOSP WAY WITHIN 60 FEET OF THE GROVE AVENUE/WINTERGREEN DRIVE INTERSECTION BY: T. COTTER PERIOD: DATE: 9-16-05 FROM: 7-1-01 TO: 6-30-05 NUMBER OF TRAFFIC COLLISIONS BY TYPE YEAR TOTAL 2003 1 2004 1 CY GROVE AVENUE ► \'£HICL£ 0 FAULT ---I> \'£H. MOVING FORWARD ~ VEH. MOVING BACKWARD ----{> PEOESlRIAN [=> PARKED VEHICLE □ AXED OBJECT 0 PROPERTY DAMAGE ONLY ® INJURY • FATAL ~ OUT OF CONlROI. ROLLO\'£R PROPERTY INJURY FATAL DAMAGE 1 0 0 1 0 0 ~ ; >-<( ~ s: ~~ Q_ U) ~~ 0 L.J ::::r:: I • LEGEND ----iXXJ--HEAD-ON CONST ESS ~ HEAD-ON SIOES\\lPE FTC HBO :rrg PASSING SIOES\\lPE H&R ILC r RIGHT ANGLE IP IT IS ~ 18 PASSING TURN LIGHT DARK WET 0 1 0 0 1 1 WINTERGREEN DRIVE ~ NO SCALE CONSTRUCTION INATT INATTENTION EXCEEDING SAFE SPEED M/C MOTORCYCLE FOLLO\\lNG TOO CLOSE RSS RAN STOP /SIGNAL HAD BEEN DRINKING VRW VIOLATED R-0-W HIT & RUN ws l'IRONG SIDE IMPROPER LANE CHANGE DIil DRIVING ~IL£ INTOXICATED IMPROPER PASS 0TH OTHER IMPROPER TURN IMPROPER START COLLISION DA TA DESCRIPTION IMPROPER BACKING (COLL. FACTOR) (REP. #) ... (DA TE) (TIME) ~ I August 30, 2005 JONT. KIMP.E. ASSOCIATE ENGINEER TRANSPORTATION DIVISION CITY OF CARLSBAD MR.KIM, ( I AM WRITING IN RESPONSE TO YOUR LEITER OF JULY 21, 2005 DENYING MY REQUEST FOR AN ALL WAY STOP AT WINTERGREEN AND HOSP/GROVE AVENUES.I UNDERSTAND THAT THERE IS AN APPEALS PRO CESS THAT CAN BE UTILIZED. PLEASE CONSIDER THIS LETTER AS MY REQUEST TO PROCEED WITH THAT PROCESS. I BELIEVE THE REASONS STATED IN MY ORIGINAL REQUEST STAND ALONE. THERE IS AN UNSAFE INTERSECTION THAT CONSISTS OF TWO BLIND CURVES THAT INTERSECT ON AN UPHILL GRADE.AS YOU STATED IN YOUR LETTEi YOUR INVESTIGATION CONClJRREDTHAT :THE LINE OF SITE IS LIMITED.YET, MY REQtrEstwAs: DENIED BASED ON THE' ' • • ~f~~i°t~t:~t~~\=~~J~=~~gis~CD CITY OF CARLSBAD REALLY WANT TO USE MINIMUM STANDARDS FOR THE SAFETY OF ITS CITIZENS WHEN THE QUESTION OF SAFETY IS BEING CALLED INTO QUESTION? THE HOMEOWNERS USING THIS INTERSECTION WANT TO BE ABLE TO EXIT WINTERGREEN/GROVE A VENUES WITH SOME REASONABLE EXPECTION THAT THE INTERSECTION IS CLEAR. THIS IS NOT THE CASE WHEN TRAFFIC VOLUMES ARE EQUAL TODAY. WE DO AGREE THAT HOSP WAY IS MORE HEAVILY IRA VELED BUT THAT IS OF LITTLE VALUE TO SOMEONE ATTEMPTING TO EXIT THESE TWO STREETS .. TRAFFIC COLLISION HISTORY AT THIS INTERSECTION IS LOW ACCORDING TO YOUR TRAFFIC STUD~HOWEVER, THAT DOES NOT REASSURE. THOSE OF US WHO USE THIS ROADWAY ON A DAIL YBASIS. HOW DO YOU RECORD NEAR MISSES? THE FACT REMAINS THAT IN THE FQUR YEAR PERIOD THAT I HA VE RESIDED ON THIS s::nIBET TBERE HAVE. BEEN TWO IN~T ANCES • WHERE CARS HAVE CRASHED INTO A HOME THAT BACKS UP TO :HOSP WAY AT THIS INTERSECTION:rms IS IN ADDITION TO THE SINGLE CAR ACCIDENT THAT CRASHED INTO THE REARY ARD OF ANOTHERHOME.I HAVE VIEWED SEVERAL NEAR ACCIDENTS MYSELF AS WELL AS BEING AMOST HIT A NUMBER OF TIMES. DOES SOMEONE HA VE TO KILLED OR SEVERL Y INWRED BEFORE ACTION IS TAKEN. I URGE THE CITY TO TAKE APPROPRIATE ACTION BEFORE THAT HAPPENS. WHY WAS A STOP SIGN INSTALLED AT HOSP WAY AND FOREST VIEW WAY THAT SERVES ONLY 20 HOMES WHEN THERE ARE 72 HOMES THAT USE THE WINTERGREEN/GROVE INTERSECTION. IT WOULD BE INTERESTING TO SEE THE TRAFFIC STUDY DONE AT THE TIME OF ITS INSTALLATION. THIS EXIT IS NOWHERE AS DANGEROUS AS THE ONE AT WINTERGREEN/GROVE AVENUES. I WOULD THINK THAT THE PREVENTION OF ACCIDENTS WOULD BE PARAMOUNT TO THE CITY OF CARLSBAD. I MAY BE REACHED AT 760-720-4932 IF I CAN BE OF ASSISTANCE. I WILL BE OUT OF COUNTRY ON VACATION FROM SEPTEMBER 2 THRU SEPTEMBER 30. THANK YOU FOR YOUR CONSIDERATION. ~1£f4_ ~ WANDA WOOD