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Home My WebLink AboutRPT 3 TRAFFIC SIG STDY 12-07-87REPORTS TO: WILLIAM HUSTON, CITY MANAGER · FROM: PUBLIC WORKS DEPARTMENT/ENGINEERING DIVISION SUBJECT: TRAFFIC SIGNAL WARRANT STUDY FOR "B" STREET AT FIRST STREET RECOMMENDATION Receive and file. BACKGROUND The attached report is a follow-up to a previous study which Staff has completed on the subject intersection of First and "B" streets. Also attached is a copy of the various traffic signal warrants. As outlined within the attached Traffic Engineer's Report, the subject i~tersection does not meet the warrants for the installation of a traffic signal at this time. Bob Ledendecker Director of Public Works/City Engineer BL/mv Attach. TO: Bob Ledendecker, Director of Public Works/City Engineer FROM: Oennis O. Barnes, Consulting City Traffic Engineer SUBJECT: Final Report on Traffic Signal Request for the Intersection of First Street and "B" Street BACKGROUND' A request was made by City Council to the Engineering Division to perform an engineering study of the First Street and "B" Street intersection with regard to impaired visibility, needed improvements and a warrant analysis for the possible installation of a traffic signal. Therefore, the Engineering Division authorized the Consulting City Traffic Engineer to perform an engineering study which would address City Council's stated concerns. The results of this study were submitted to the City Manager on September 1, 1987 for submittal to City Council on September 8, 1987. City Council accepted the interim recommendations, for school signing improvements at this location and the recommendation to perform another engineering study after school had been in session for at least two weeks. EXISTING CONDITIONS' At the intersection of first Street and "B" Street, there is an existing school crosswalk which crosses First Street on the east side of the intersection. In addition, there are school crosswalks on the north and south sides of the intersection which cross "B" Street. All of these crosswalks are on the school route to the Helen Estock Elementary School. Since it was believed that a traffic signal might be justified under the School Protection Warrant, school-age pedestrian counts were taken on First Street at two different time periods for a total of 6-3/4 hours. The time periods counted were from 7-00 A.M. to 9:15 A.M. and from 11'30 A.M. to 4:00 P.M. The results are summarized as follows' Locati on Time Peri od Number of Pedestrians First Street 7:00 A.M. - 9:00 A.M. 46 First Street 11:30 A.M. - 4:00 P.M. 63 "B" Street 7:00 A.M. - 9:15 A.M. 38 "B" Street 11:30 A.M. - 4:00 P.M. 47 In addition to the pedestrian counts, traffic volume counts were made for First Street and "B" Street.. The intent was to check each street for compliance to the minimum vehicular vOlumes required by the School Protection and Minimum Vehicular Volume Signal Warrants. Traffic Signal, First & "B" Street November 6, 1987 Page 2 As stated in the previous report, a review of the accident data for a three-year period (1984-1986) indicated that there were only three correctible right-angle type accidents at this location. EVALUATION: The State of California Department of Transportation (Caltrans) has adopted eleven nationally recognized guidelines which are used in determining the need for traffic signal control. Since the subject location did not come close to meeting any of these warrants in the last engineering study, only the Minimum Vehicular Volume and School Protection Warrants were evaluated this time. Traffic counters were placed at the subject intersection for two 24-hour periods starting at 7:00 A.M. on September 21, 1987. The results of these traffic counts indicated that First Street met the minimum traffic signal volume warrant for fifteen (15) of the required eight (8) hours, whereas "B" Street did not meet the volume warrant for even one hour. The results of this engineering investigation are identical to those of the previous study. Hence, it can be concluded that the installation of a traffic signal is not warranted at this time. Dennis D. Barnes, P.E. Consulting City Traffic Engineer DDB/mv Traffic Manual DIST Major St: Minor St: CO'" RTE PM TRAFFIC SIGNALS AND LIGHTING Flgure 9-1A TRAFFIC SIGNAL WARRANTS CALC CHK DATE Critical Approach Speed ~ mph Critical Approach Speed~ mph Critical speed of major street traffic_~ 40 mph In built up area of isolated community of ~_.10,000 pop. WARRANT 1 - Minimum Vehicular Volume o. RURAL (R) ......... [~ URBAN (U) YES 100% SATISFIED 80% SATISFIED YES r"l No 12-1986 MINIMUM REQUIREMENTS ul.' APPROACH~NES ' 2or Minor Street' (120) (~)(160) Hour * NOTE: Heavier left turn movement from Major Street included when z. T-phasing is proposed ['-] WARRANT 2- Interruption of Continuous Traffic 10o~..-. SATISFIED YES D NO 80~.o SATISFIED YES I"1 NO MINIMUM REQUIREMENTS UlR // :/ APPROACH , ' or more ~'~;/ ~ / / / LANES Both Apprch$. 750 525 900 630 Major Street (600) (420) (720) (504) Highest APl:)rch. 75 53 100 70 Minor Street' (60) (42) (80) (56) *NOTE: Heavier left turn movement from Major Street included when L'l-phasing is proposed r"] WARRANT 3- Minimum Pedestrian Volume Hour 100% SATISFIED 80% SATISFIED YES YES r-! NO MINIMUM REQUIREMENTS ~.. (a0~ll~ SHOWN IN BRACKETS) U R B'~)th Al~'prchs. No Median600 420 / / / / / / / Major Street (480) (336) Raised 1000 700 · Volume 4' Median (800) (560) Ped'$ On Highest Volume 150 105 X-Walk Xing ~_ajor Street (120) (84) IF MIDBLOCK SIGNAL PROPOSED I-I MIN. REQUIREMENT DISTANCE TO NEAREST ESTABLISHED CRWLK. FULFILLED '150 Feet N/E ,,, ff S/W ff' Yes r-] No I"] Hour The satisfaction of a warrant is not neces~,/ily justification for a signal. Delay, congestion, confusion or other evidence of the need for right of way assignment must be shown.. 12-1~86 TRAFFIC SIGNALS AND LIGHTING IIII I I Figure 9-1 B TRAFFIC SIGNAL WARRANTS Traffic Manual WARRANT 4 - School Crossings Not Applicable ~.~ See School Crossings Warrant Sheet WARRANT 5- Progressive Movement SATISFIED YES r'! NO [~ MINIMUM REQUIREMENTS DISTANCE TO NEAREST SIGNAL FULFILLED · ,ooo. N , s .,= 7£O .,w/... 120 ft YES r'"l NO ON ONE WAY ISOLATED ST. OR ST. WITH ONE WAY TRAFFIC SIGNIFICANCE AND ADJACENT SIGNALS ARE SO FAR APART THAT NECESSARY PLATOONING & SPEED CONTROL WOULD BE LOST ON 2-WAY ST. WHERE ADJACENT SIGNALS DO NOT PROVIDE NECESSARY PLATOONING & SPEED CONTROL. PROPOSED SIGNALS COULD CONSTITUTE A PROGRESSIVE SIGNAL SYSTEM D I'-] WARRANT 6- Accident Experience SATISFIED YES r"l NO !~ ' v~ ' FULFILLED '" REQUiREmENT WARRANT .., ONE WARRANT WARRANT 1 - MINIMUM VEHICULAR VOLUME ., ! mm,. mm i I I i I i .,,,. - - -. - - - - - ',. · OR. SATISFIED WARRANT 2 - INTERRUPTION OF CONTINUOUS TRAFFIC 80~ WARRANTOR 3- MINIMUM PEDESTRIAN VOLUME YE'.~ l-'} NO SIGNAL WILL hOT SERIOUSLY DISRUPT PROGRESSIVE TRAFFIC FLOW D , ADEQUATE TRI~,L OF LESS RESTRICTIVE REMEDIES HAS FAILED TO REDUCE ACC. FREQ. D L~ ACCWlTH~NA12 MON. PERIOD SUSCEPTIBLE OF CORR. & INVOLVING INJURY OR ~ $200 DAMAGE I mm m ~ I I MINIMUM REQUIREMENT NUMBER OF ACCIDENTS * NOTE: Left turn accidents can be included wh~. LT-phasing is proposed WARRANT 7 - Systems Warrant SATISFIED YES I'"1 NO [~' MINIMUM VOLUME ENTERING VOLUMES - ALL APPROACHES v/ FULFILLED REQUIREI~AENT DURING TYPICAL WEEKDAY PEAK HOUR VEH/HR 800 VEH!HR ................................................... DURING EACH OF ANY 5 HRSvEH/HROF A SATURDAY AND/OR SUNDAY YES D NO ,, - CHARACTERISTICS,OF MAJOR ROUTES MAJOR ST MINOR ST_ -Hwy SYSTEm"SERVING AS PRINCIPLE N~:TWORK FOR THROUGH TRAFFIC , CONNECTS AREAS OF PRINCIPLE TRAFFIC GENERATION .RURAL OR SUBURBAN HWY OUTSIDE OF, ENTERING, OR TRAVERSING A CITY HAS SURFACE STREET F'WY OR EXPWAY RAMP TERMINALS m m m m m m ~ 'Imm m mm mmm m m m m m m m m mm m mm m m APPEARS AB I~IAJOR ROUTE ON AN OFFICIAL PLAN · ANY MAJOR ROUTE CHARACTERISTICS MET, BOTH STS. The satisfaction of a war~ant is not necessarily justification for a signal. Delay, congestion, confusion or other evidence of the need for right of way assignment must be shown. I~-10B Traffic Manual TRAFFIC SIGNALS AND LIGHTING 9-7 12-1~86 Figure 9-1C TRAFFIC SIGNAL WARRANTS WARRANT 8- Combination of Warrants SATISFIED YES' I"1 NO [~ REQUIREMENT WARRANT v' FULFILLED TWO WARRANTS 1 - MINIMUM VEHICULAR VoLuME SATISFIED 2- INTERRUPTION OF CONTINUOUS TRAFFIC 8096 3- MINIMUM PEDESTRIAN VOLUME YES i"1 NO WARRANT 9- Four Hour Volume SATISFIED* YES [~] NO L~ Approach Lanes One more ~ Hour *Refer to Fig. 9-2A (URBAN AREAS) or Figure 9-2B (RURAL AREAS) to determine if this warrant is satisfied. WARRANT 10-Peak Hour Delay SATISFIED YES r"! NO 1. The-total delay expErienced for traffic on one minor street apprOach controlled by a STOP sign equals or exceeds four vehicle-hours for a one-lane approach and five vehicle-hours for a two-lane approach; and YES I-1 NO ~/ 2. The volume on the same minor street approach equals or exceeds 100 vph for one moving lane of traffic or 150 vph for two moving lanes; and YES r-'! NO [~ 3. The total entering volume serviced during the:hour equals or exceeds 800 vph for intersections with fcur or more approaches or 6~50 vph for intersections with three approaches. ,~ YES[~ NO 1'3 WARRANT 11 - Peak Hour Volume SATISFIED* YES I-'1 NO [~ 2 or Approach Lanes ' One more [~.-- I P~ Hour Bot",, , Appro,che$ , Major Street I"l;ghes, AI3proaches , Minor Street *Refer tO Fig. 9-2C (URBAN AREAS) or Figure 9-2D (RURAL AREAS) to determine if this warrant is satisfied. The satisfaction of a warrant is not necessarily justification for a signal. Delay, congestion, confusion or other evidence of the nee. d for right of way assignment must be shown. TS-~OC ~ · Traffic Manual _ TRAFFIC SIGNALS AND LIGHTING DIST Major St: Minor St: Figure 9-1 E SCHOOL PROTECTION WARRANTS CALC D.D. /~-Y'/'/~'$DATE/~-2'3-~7 CO RTE P.M. Critical speed of approach traffic_~40 mph C H K DATE In built up area of isolated community of~ 10,000 pop. Critical Approach Speed ~O mph CriticalApproach Speed ~ mph o~ RURAL (R) URBAN (U) 9-9 IIII 12-1~M ii FLASHING YELLOW SCHOOL SIGNALS (All parts must be satisfied) Minimum Recluirements / Each of 200 140" Vehicle Volume 2 hours School Age Pedestrian Each of 40 40 Crossing Street 2 hours ..... AND PART B Critical Approach Speed Exceeds 35 mph AND PART C Is nearest controlled crossing more than 600 feet away?. SATISFIED YES r"l NO SATISFIED YES r"l NO L~ SATISFIED YES [-I NO ~ SATISFIED YES ~NO SCHOOL AREA TRAFFIC SIGNALS (All parts must be satisfied) .,, Minimum Requ_.j~ements ~/(~)~//(~?/ PART A : R _ .- Each of 500 350 ~OO{ /,~ Vehicle Volume 2 hours ' Eacho, 70 37 Ze Sch~ol Age Pedestrians .~.h~?. , .............. Crossing Stree~ or 500 350 ~ per day ~ PART B AND .. Is nearest controlled crossing more than 600 feet away?. SATISFIED YES D NO '~ SATISFIED YES I"1 NO SATISFIED YES ~NO I"1