The URL can be used to link to this page

Home My WebLink AboutCT 85-28; LA COSTA VALLEY; TRAFFIC STUDY; 1985-12-26w ... ~ d'tD + ~ p ~ Wiu;fmt PWtgee cu«l Ar,3~ RECEIVED DEC 3 0 '10) • .J ~ A TRAFFIC & TRANSPORTATION ENGINEERING December 26, 1985 Mr. Eric Barthelemy • . John Ash A.I.A. & Associates 8800 Venice Boulevard Los Angeles, CA ·90034 Dear Mr. Barthelemy: This letter summarizes our review of traffic factors related to the proposed La Costa Valley Terrace project in the City of Carlsbad. The study is hased upon information provided by you, previous studies and standard reference data. The project consists of 34 residential dwelling units and is located on the . southeasterly corner of Altisma Way __ and Caringa Way in the_La Costa area of the City of Carlsbad. Vehicular a·cces-s is provided on both streets. The surrounding ' . • area is developed with residential uses and both streets function as local streets. Figure 1 illustrates the site location and surrounding street system. EXISTING TRAFFIC CONDITIONS . . Altisma Way and Caringa Way are fully improved streets and provide access between the project site and the arterial street system. Alicante Road is classified as a Secondary Arterial and_ is fully improved. Alga Road is classified as a Major Arterial and is fully developed from E] Camino Real to El Fuerte Street. The intersections on Alga Road at El Camino Real and A]icante Road are currently signalized. PM' peak hour traffic counts were completed on Alga Road at El Camino Real and -. . at Alicante Road by Weston Pringle and Associates in October, 1985. These data were utilized to quantify existing traffic conditions with Intersection Capacity Utilization (ICU) analyses. (The ICU methodology and relationship of ~CU to Level of Service are described in Appendix A.) These ICU analyses are contained in Appendix Band indicate an existing _ICU value of 0.27 (Level of Service A) at Alicante Road and Alga Road and an ICU value of 0.45 (Level of Service A) at Alga Road and El Camino Real. An ICU analyses of existing conditions had previously 2651 EAST CHAPMAN AVENUE • SUITE 110 • FULLERTON, CALIFORNIA 92631 • (714) 871-2931 5 ,. 30% 25% 5% -ro 15 -~-N-- NO SCALE COST~ \.l WESTON P~INGLIE AND ASSOCIATES • LEGEND _25,-pM PEAK HOUR (2501 TWO WAY DAI LY 25% DISTRI BU Tl ON TRIP DISTRIBUTION PROJECT DAILY 8.PM ·pK HR TRIPS LA COSTA VALLEY TERRACE FIGURE· 4010 5% ::0 .o . . . -2- been completed for the El Camino Real and La Costa Avenue intersection. This calculation is also contained in Appendix Band indicated a current ICU value of 0.98 (Level of Servjce E). TRIP GENERATION In order to examine project traffic, it is necessqry to estimate the number of trips that would be generated by the project. Daily trip generation rates for various land uses have been established by the City's Traffic Model and peak hour rates have been developed in other previous studies. The rates utilized in this study are listed in Table 1. A]so listed in Table 1 are the estimated trips to be generated by the project. As indicated, the project is estimated to gene- -. r~te 270 daily trip ends with 35 occurring during the PM peak hour. TRIP ASSIGNMENT Trip distribution patterns for residential projects in the la Costa area have been developed in previous studies. The distribution for the site is illustrated on Figure 1. This distribution represents the existing road system and would be expected to change with the ultimate circulation system. Estimated project traffic was assigned to the road system in conformance with the distribution pattern. The daily and PM peak hour project assignment is illustrated on Figure 1. Intersection traffic assignments were also completed and are summarized in Appendix B. ANALYSIS Potential traffic impacts from the project have been analyzed for two conditions. First, conditions upon project completion including other planned development were examined. Second, conditions at General Plan build out were evaluated with . . respect to the planned development. The ICU analyses completed to quantify existing conditions provided a basis for the proje~t completion analysis. Estimated project traffic and anticipated traffic from other projects that have been approved or are being processed were combined with existing traffic to simulate conditions upon project completion. ICU analyses were completed for existing plus other and existing plus other plus ~roject con- 3 -3- Table 1 TRIP GENERATION La Costa Valley Terrace TIME PERIOD TRIP ENDS PER GENERATED TRIPS DWELLING UN IT (34 DU's -RM) Daily 8 270· PM Peak Hour In 0.8 30··· Out .. 0.2 5 Total 1.0 35 -4- ditions and are contained in Appendix B. The results of these analyses are summarized in Table 2 along with a listing of other projects utilized in these analyses. Review of Table 2 indicates that the intersections on Alga Road at El Camino Real and Alicante Road would continue to operate at acceptable Levels of Service at project completion. The El Camino Real/La Costa Avenue inter-- section would operate at an unacceptable Level of Service; however, there is no impact as a result of this project. The intersection of El Camino Real and La Costa Avenue was futther examined to determine conditions with intersection improvements. A plan to improve this intersection is currently being considered by the City. With these proposed improvements, the IC~ value becomes 0.65 and Level of Service Bis obtained. The intersection of Rancho Santa Fe Road and Melrose Avenue was also examined with improvements related to adjacent development. As indincated in Table 2, acceptable conditions are also projected for this intersection at project com- pletion.· _ The City has developed a Traffic Model to project traffic volumes at build out of the General Plan. This Model also proivdes peak hour intersection volumes which can be utilized for ICU analyses. ICU analyses were completed for three area intersec~ions and are contained in Appendix C. The results of these ICU analyses are summarized in Table 3. As indicated in Table 3, some improvement over standard intersection geometrics will be required. With improvements such as dual left turn lanes, right turn lanes and additional through Janes, the ICU can be reduced as indicated in Table 3. There is a need to further validate the traffic projections and develop intersection design requiremnets. A study of this type is currently underway and is expected to be completed in early 1986. SUMMARY J . . This study has examined traffic factors related to the proposed La Costa Valley Terrace residential development in the City of Carlsbad. Exi'sting traffic con- ditions were quantified to provide a basis for the study. Estimates were made of trips to be generated by the project and the ability of the circulation system to accommodate these trips evaluated. Consideration was given to approved Table 2 ICU SUMMARY At Project Completion La Costa Valley Terrace INTERSECTION Existing El Camino Real/La Costa Avenue ICU 0.98 LOS E El Camino Real/Alga Road~.J-1-e~e Bwd. ICU 0.45 LOS A Melrose Avenue/Rancho Santa Fe Raod-Corintia ICU LOS Alga Road/Alicante Road ICU 0.27 LOS A -5- Existing Existing Existing +Other(2) +Other(2) +Other(2) +Project +Project W/Imprv. 1.21 1.21 0.65 F F B 0.62 0.63 B B 0.34 A 0.40 0.40 A A (1) ICU=Intersection Capacity Utilization; LOS=Leve] of Service (2) Other Projects: La Costa Southwest Phase La Costa SE 16 La Costa SE 18-21 Parcel 0.95 The Meadows Meadow Ridge SW Corner Alga/Melrose 1 (SWl-4) Alicante Views Alicante Hills Crossroads Alicante View Apartments Casa Loma Condos Alga Road Residential INTERSECTION Table 3 ICU SUMMARY At General Plan Build Out La Costa Valley Terrace El Camino·Real/La Costa Avenue ICU LOS El Camino Real/Alga Rad-College Blvd. ICU LOS Melrose Avenue/Rancho Santa Fe Road-Corintia ICU LOS General Plan 1.50 F 1.56 F (1) ICU=Intersection Capacity Utilization; LOS=Level of Service -6- General Plan W/Imprv. 1.01 F 0.88 D 1.04 F 1 -7- and proposed projects in the area. Intersection analyses at project completion and General Plan build out indicated that ·the planned circulation system can accommodate the project. Principal findings of the study are the following: 1. The proposed development would generate an estimated 270 daily trip ends with 35 occurring during the PM peak hour. 2. The existing intersections on Alga Road at El Camino Real and Alicante Road will operate at acceptable Levels of Service at project completion 3. While the El Camino Real/La Costa Avenue intersection is projected to operate at an unacceptable Level of Service, the project would not contribute to the deficiency. • ' 4. With currently proposed improvements, both the El Camino Real/La Costa Avenue and Rancho Sante Fe Road/Melrose Avenue intersections will operate at acceptable Levels of Service. * 5. At build out conditions, some additional circulation improvements may be required as will be identified in the study currently underway. 6. _No traffJc mitigation measures are required for this project. * * * * We•trust that this study will be of assistance to you and the City of Carlsbad * in the processing of this project. If you have any questions or require additional information, please cqntact us. . -Respectfully submitted, WESTON PRINGLE & ASSOCIATES ~~~ Weston S. Pringle, P.E. Registered Professional Engineer State of California Numbers Cl6828 & TR565 WSP:bas #852080 8 .• : . . ; .. , .. ., . ~' : . ': .• -·,,. ' . . . ' ,., ~ . APPENDIX A EXPLANATION OF INTERSECTION CAPACITY UTILIZATION •• · AND LEVEL OF SERVICE . . ·. ·.· • • •• f . . . . . . . .. . :. -. . . . . • ◄ •• .. . : ---• . .,. -. . . . -. ' . . . . . ' ~ , _' ~ • .,t • ', .. ,,. .. ' .. ••, :. •. . ' . . • .... . . . .. APPENDIX A EXPLANATION OF INTERSECTION CAPACITY UTILIZATION The capacity of a street is nearly.always greater between intersections and less at intersections. The reason for this is that the traffic flows continuously between intersections and only part of the time at intersections. To study intersection capacity, a technique known as Intersection Capacity Utilization (ICU) has been developed. ICU analysis consists of {a) determinin~ the pro- portion of signal time needed to serve each conflicting movement; {b) summing the times for the movements; and (c) comparing the total time required to the time available. For example, if for north-south traffic the northbound traffic is 1,000 vehicles per hour, thesouthbound traffic is 800 vehicles per hour, and the capacity·of either approach is 2,000 vehicles per hour of green, then the northbound traffic is critical and requires l,000/2,000 or 50 percent of the· signal time. If for the east-west traffic, 40 percent of the signal time_ is required, then it can be.seen that the ICU is 50 plus 40, or 90 percent. When left-turn phases exist, they are incorporated into the analysis. As ICU's approach 100 percent, the quality of traffic service approaches Level of Service {LOS) E, as defined in the Highway Capacity Manual, Special Report 87, Highway Research Board, 1965. • • Level of Service is used to describe quality of traffic flow~ Levels of Service A to C operate quite well. Level of Service Dis typically the Level of Service for which an urban street is designed. Level of Seryice Eis the maximum volume a facility can accommodate and will result in possible stoppages of momentary duration. Level of Service F occurs when a facility is overloaded and is characteri?ed by stop-and-go traffic with stoppages of long duration. A des- cription of the various levels of service appears on the following page. The ICU calculations assume that an intersection is signalized and that the signal is ideally timed. Although calculating ICU for an unsignalized inter- section is not valid, the presumption is that a signal can be installed and the calculation shows whether the geometrics are capable of accommodating the ex- pected volumes. It is possible to have an ICU well below 1.0, yet have severe traffic congestion. This would occur because one or more movements is not getting enough time to satisfy.its demand with excess time existing on other moves. Capacity is often defined in terms of roadway width. However~ standard lanes have approximately the same capacity whether they are 11 foot or 14 foot lanes. Our data indicates a typical lane, whether a through lane or left-turn lane has a capacity of approximately 1600 vehicles per lane per hour of green time. The Highway Capacity Manual found capacity to be about 1500 vehicles per lane per hour of green for through lanes and 1200 vehicles per lane per hour of green for left-turn lanes. However, the capacity manual is based on pre-1965 data, and recent studies and observations show higher capacities in the southern California area. For this study a capacity of 1600 vehicles per lane has been assumed for through traffic, and 1600 vehicles per lane for turning lanes. -• lo APPENDIX A LEVEL OF SERVICE DESCRIPTIONS Level of Service A B C D E F {a) Low volumes; high speeds; speed not restricted by other vehicles; all signal cycles clear with no vehicles waiting through more than one signal cycle. Operating speeds beginning to be affected by other traffic; between one and ten percent of the signal cycles have one or more vehicles which wait through more than one signal cycle during peak traffic periods. Operating speeds and maneuverability closely controlled by other traffic; between 11 and 30 percent of the signal cycles·have one or more vehicles which wait through' more than one signal cycle during peak traffic periods; recommended ideal design standard. Tolerable operating speeds; 31 to-70 perceni of the signal cycles have one or more vehicl_es which wait through more than one signal cycle during peak traffic periods; often used as design standard in urban areas. Capacity; the maximum traffic volumes an inter- section can accommodate; restricted speeds; 71 to 100 percent of the signal cycles have one or more vehicles which wait through more than one signal cycle during peak traffic periods. - Long queues of traffic; unstable flow; stop- pages of long duration; traffic volume and traffic speed can drop to zero; traffic volume will be less than the volume which occ~rs at Level of Service E. ICU (Intersection Capacity Utilization) at various Levels, of Service versus Level of Service E for urban arterial streets. Nominal Range Of ICU (a) 0.00 -0.60 0.61 -0.70 0.71 -0~80 0.81 .. 0.90 0.91 ''."' 1.00 Not meaningful /I .. ' ' , ·-. ~ . : .· . . . ,· ... - APPENDIX a· -ICU ANALYSES . PROJECT COMPLETION 12 .. INTERSECTION CAPACITY UTILIZATION ANALYSIS LA COSTA VALLEY TERRACE At Project Completion INTERSECTION: • EL CAMINO REAL/ LA COSTA AVE (PM Peak Hour) MOVE-EXIST PROP EXIST PROP EXIST OTHER PROJ EXIST E+O E+O+P E+O+P W/ MENT LANES LANES CAP CAP VOL· VOL VOL V/C V/C VIC , IMPR V/C -NL 1 2 160.0 3200 234 40 0.15 * 0.17 * 0.17 * 0.09 * NT 2 3 3200 4800 416 45 0.15 0.16 0.16 0.11 NR 0 0 56 SL 1 2 1600 3200 164 70 0.10 0.15 0.15 0.07 ST 2 3 3200 4800 447 75 0.25'* 0.29 * 0.29 * 0.19 * SR 0 0 350 55 EL 1 2 1600 3200 414 170 5 0.26 0.37 0.37 0.18 * ET 1 2 1600 3200 418 110 0.49 * 0.66 * 0.66 * 0.17 ER 0 1 1600 360 160 0.33 WL 1 1 '1600 1600 70 0.04 * 0.04 * 0.04-* 0.04 WT 1. 2 1600 3200 281 20 .... 0.18 0.19 0.19 0.14 * WR 1 0 1600 120 15 , . .. • 0.08 0.08 0.08 ,, .,"· NORTH/SOUTH CRITICAL SUMS= 0.40 0.46 0.46 0.28 EAST/WEST CRITICAL SUMS=.· 0.53 0.70 0.70 0.32 -CLEARANCE = • 0.05 0.05 0.05 0.05 ICU= 0.98 1.21 1.21 0.65 LOS= E F F B N=NORTHBOUND,S=SOUTHBOUND,E=EASTBOUND,W=WESTBOUND .,, ,, L=LEFT,T=THROUGH,R=RIGHT *DENOTES CRITICAL MOVEMENT ILCVPCPl . INTERSECTION CAPACITY UTILIZATION ANALYSIS LA COSTA VALLEY TERRACE At Project Completion INTERSECTION: EL CAMINO REAL/ ALGA RD -COLLEGE BLVD (PM Peak Hour) MOVE-EXIST EXIST EXIST OTHER PROJ EXIST. E+O E+O+P MENT LANES CAP VOL VOL VOL V/C V/C V/C NL 1 . 1600 95 25 0.06 * 0.08 0.08 NT 3 4800 499 35 0.10 0.11 * 0.11 * NR FREE 0 441 170 5 SL 1 1600 216 315· . 10 0.14 0.33 * 0.34 * ST 2 3200 674 140 0.23 * 0.29 0.29 SR 0 56 55 EL 1 1600 21 10 0.01 0.02 0.02 ET 2 3200 11 5 0.02 * 0.02 * 0.02 * ER 0 41 5 WL 2 3200 256 55 . 0.09 * 0.11 * 0.11 * WT 0 18 10 ' , ,0.00 0.00 0.00 WR FREE 0 139 90, '5 .,to, NORTH/SOUTH CRITICAL SUMS= 0.29 0.44 0.45 .EAST/WEST CRITICAL SUMS = 0.11 0.13 0.13 -. ', . CLEARANCE= 0.05 0.05 0.05 ICU= 0.45 0.62 0.63· LOS= A B B N=NORTHBOUND,S=SOUTHBOUND,E=EASTBOUND,W=WESTBOUND L=LEFT,T=THROUGH,R=RIGHT *DENOTES CRITICAL MOVEMENT ILCVPCP2 --1:. ~ INTERSECTION CAPACITY UTILIZATION ANALYSIS LA COSTA.VALLEY TERRACE .. At Project Completion ,1•.· ,, ••" • INTERSECTION: MELROSE AVE / RANCHO SANTA FE RD-CORINTIA (PM Peak Hour) MOVE-PROP PROP EXIST OTHER PROJ E+O E+O+P MENT • LANES CAP VOL VOL VOL ·w/IMPR W/IMPR V/C V/C NL i' 1600 0 25 0.02 0.02 NT 3 4800 75 35 0.02 * 0.02 * NR FREE 719 115 SL 2 3200 88 55 0.04 * 0.04 * ST 3 4800 42 15 0.01 0.01 SR 0 0 EL 1 1600 0 0.00 0.00 ET 1 1600 0 20 0.02 * 0.02 * ER 0 0 5 WL 3 4800 508 425 0.21 * o·. 21 * WT 0 0 80· o.oo 0.00 WR 1 1600 110 ,. 190 15 0.19 0.20 NORTH/SOUTH CRITICAL SUMS= 0.06 0.06 EAST/WEST CRITICAL SUMS= 0.23 0.23 CLEARANCE = 0.05 0.05 ICU= 0.34 0.34 LOS= A A .. '• N=NORTHBOUND,S=SOUTHBOUND,E=EASTBOUND,W=WESTBOUND L=LEFT,T=THROUGH,R=RIGHT · *DENOTES CRITICAL MOVEMENT ILCVPCP3 -V\ INTERSECTION CAPACITY UTILIZATION ANALYSIS LA COSTA VALLEY TERRACE At Project Completion INTERSECTION: ALGA ROAD/ ALICANTE ROAD (PM Peak Hour) MOVE-EXIST EXIST EXIST OTHER PROJ EXIST E+O E+O+P ·MENT LANES CAP VOL VOL VOL V/C V/C V/C NL 1 . 1600 94 80 5 0.06 * 0.11 * 0.11 * NT 0 0.00 0.00 NR 1 1600 8 0.01 0.01 0.01 SL 0 ST 0 SR 0 EL 1 1600 17 0.01 0.01 0.01 ET 2 3200 485 255 0.15 * 0.23 * 0.23 * ER 1 1600 158 235 15-0.10 0.25 0.26 WL 1 1600 23 0.01 * 0.01 * . 0.01 * WT 2 3200 248 75 ~-0.08 0.10 0.10 WR 0 , •' ,I ,v ... NORTH/SOUTH CRITICAL SUMS= 0.06 0.11 0.11 , EAST/WEST CRITICAL SUMS= 0.16 0.24 0.24 CLEARANCE= 0.05 0.05 0.05 ICU= 0.27 0.40 0.40 LOS =_ A A A N=NORTHBOUND,S=SOUTHBOUND,E=EASTBOUND,W=WESTBOUND L=LEFT,T=THROUGH,R=RIGHT *DENOTES CRITICAL MOVEMENT -ILCVPCP4 ...... " . . • I .• ' . . . ... , ... · APPENDIX C ICU ANALYSES BUILDOUT . 7 • 's-'· '.• • .. . . , . ~. -: ('O INTERSECTION CAPACITY UTILIZATION ANALYSIS LA COSTA VALLEY TERRACE .. ,: At Gen·eral Plan Build-out INTERSECTION: EL CAMINO REAL/ LA COSTA AVE (PM Peak Hour) MOVEMENT NL NT NR SL ST SR EL ET ER WL WT WR GEN PLAN PROPOSED • GEN PLAN PROPOSED GP MODEL LANES LANES CAPACITY CAPACITY VOLUME 1 1 1600 1600 108 3 3 4800 4800 2204 0 1 1600 110 1 2 1600 3200 564 3 3 4800 4800 1277 0 FREE 878 1 2 1600 3200 716 2 2 3200 3200 545 0 FREE 331 1 1 1600 1600 19 2 2 3200 3200, 309 0 1 , .. 1600 246 NORTH/SOUTH CRITICAL SUMS= EAST/WEST CRITICAL SUMS= CLEARANCE = ICU= LOS=:. N=NORTHBOUND,S=SOUTHBOUND,E=EASTBOUND,W=WESTBOUND L=LEFT,T=THROUGH,R=RIGHT * DENOTES CRITICAL MOVEMENTS ILCVBOPl GP MODEL V/C 0.07 0.48 * 0.35 * 0.45 0.45 * 0.27 0.01 0.17 * 0.83 0.62 0.05 1.50 F . GP V/C W/IMPR 0.07 0.46 * 0.07 0.18 * 0.27 0.22 * 0.17 0.01· 0.10 * I 0.15 I 0.64 0.32 0.05 1.01 F i ' INTERSECTION CAPACITY UTILIZATION ANALYSIS ~ . LA COSTA VALLEY TERRACE • At General Plan Build-out ' ... INTERSECTION: EL CAMINO REAL/ ALGA RD -COLLEGE BLVD (PM Peak Hour) MOVEMENT GEN PLAN PROPOSED GEN PLAN PROPOSED GP MODEL GP.MODEL GP V/C LANES LANES CAPACITY CAPACITY VOLUME V/C W/IMPR -.NL 1 2 1600 3200 277 0.17 0.09 NT 3 3 4800 4800 1641 0.52 * 0.34 * NR 0 • FREE 865 · . SL 1 . 2 1600 3200 589 0.37 * 0.18 * ST 3 3 4800 4800 1838 0.44 0.38 SR 0 1 1600 280 0.18 EL 1 1 1600 1600 146 0.09 0.09 ET 1 2 1600 3200 398 0.36 * 0.18 * ER 0 . 0 , 174 WL 1 : 2 1600 3200 419 0.26 * 0.1~ * WT 2 2 3200 3200 .. , , ' 247 0.22 0.08 WR 0 1 .. 1600' ',' "" 456 0.29 . ,. NORTH/SOUTH CRITICAL SUMS= 0.89 0.52 EAST/WEST CRITICAL SUMS= 0.62 0.31 -CLEARANCE= 0.05 0.05 . ICU= 1.56 0.88 LOS= F D N=NORTHBOUND,S=SOUTHBOUND,E=EASTBOUND,W=WESTBOUND L=LEFT,T=THROUGH,R=RIGHT * DENOTES CRITICAL MOVEMENTS ILCVBOP2 '.' ' : ., INTERSECTION CAPACITY UTILIZATION ANALYSIS LA COSTA VALLEY TERRACE At General Plan Build-out INTERSECTION: MELROSE AVE/ RANCHO SANTA FE RD -·CORINTIA ,,: (PM Peak Hour) MOVEMENT PROPOSED PROPOSED GP MODEL GP MODEL W/ LANES • CAPACITY VOLUME IMPR V/C· .NL 1 1600 105 0.07 NT 3 4800 1700 0.35 * NR FREE 1475 SL 2 3200 625 0.20 * ST 3 4800 1540 0.34 SR 0 75 EL 1 1600 55 0.03 ET 1 1600 50 0.08 * ER 0 85 WL 3 4800 1635 0.36 * WT 0 70 WR 1 1600 485 0.30 NORTH/SOUTH CRITICAL SUMS= 0.55 EAST/WEST CRITICAL SUMS=. 0.44 CLEARANCE = 0.05 ICU= 1.04 LOS= F N=NORTHBOUND,S=SOUTHBOUND,E=EASTBOUND,W=WESTBOUND L=LEFT,T=THROUGH,R=RIGHT * DENOTES CRITICAL MOVEMENTS ILCVBOP3 ;. • .., ', -(,