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Home My WebLink About2002-04-23; City Council; 16730; Review Of Alga Road Speed ZoneCITY OF CARLSBAD -AGENDA BILL ,B# 16,730 SPEED ZONE CITY ATTY. ITG. 4/23/02 TITLE: - REVIEW OF ALGA ROAD IEPT. ENG RECOMMENDED ACTION: Staff recommends that the City Council reaffirm their previous approval of the 50 mile per hour speed zone on Alga Road. ITEM EXPLANATION: At the meeting of March 12, 2002, Jacquee Renna addressed the City Council under PublicComment and expressed concern with the posted 50 mile per hour speed limit on Alga Road. Ms. Renna stated that her observations of speeding vehicles and accidents in the road segment between El Camino Real and Alicante Road suggested a 45 mile per hour speed limit was more appropriate. On the south side of Alga Road within this segment, single-family residences have driveway access to Alga Road. The City Council directed staff to return to the City Council for a review of this issue. On August 21, 2001, the City Council adopted Ordinance No. NS-599 to establish a prima facie 50 mile per hour speed limit upon Alga Road from El Camino Real to its intersection with Melrose Drive. The City Council based their recommendation upon: 0 A review of the results of the Engineering and Traffic Survey presented by staff. 0 The recommendation of the Traffic Safety Commission made at their July 2, 2001 meeting to establish upon Alga Road a 50 mile per hour prima facie speed limit. The primary means of speed enforcement by the Carlsbad Police Department involves the use of radar. When radar is used in conjunction with a prima facie speed limit, the prima facie speed limit must be justified by the results of an Engineering and Traffic Survey. The Engineering and Traffic Survey documents roadway conditions and finds those conditions to be satisfactory for the posted prima facie speed limit. The survey considers such factors as the number of collisions that have occurred on the road segment, roadway features, adjacent land uses, driveway locations, traffic volumes, pedestrian volumes, critical speed, horizontal and vertical alignment, stopping sight distance and conditions not readily apparent to the driver. Speed zoning is based on the principle of setting speeds as near as racticable to the speed that 85% of the drivers consider to be reasonable and prudent, i.e., the 85 R percentile or critical speed. The critical speed is defined as the speed at which 85% of the drivers are traveling at or below. Speed limits are established to encourage voluntary compliance because they appear to be reasonable to a majority of the drivers. Speed trap laws in California require that the posted speed limit be justified by a valid Engineering and Traffic Survey. Section 40801 of the California Vehicle Code prohibits use of a speed trap in securing evidence of the speed of a vehicle for prosecution under the Vehicle Code. A speed trap is a particular section of a road with a prima facie speed limit that is not justified by the results of an Engineering and Traffic Survey and where enforcement involves the use of radar. I Page 2 of Agenda Bill No. 16.730 Prior to the City Council action in August 2001, the posted speed limit on Alga Road was 45 miles to be 53 miles per hour in a speed survey obtained May 22, 2001. Only 23% of the drivers were per hour. The critical speed in the road segment that Ms. Renna is concerned with was determined traveling 45 miles per hour or lower and 66% of the drivers were traveling 50 miles per hour or lower. After the 50 mile per hour speed zone was established and proper signs posted, the critical speed was found to be 54 miles per hour and 60% of the drivers were traveling at 50 miles per hour or lower. The 50 mile per hour speed zone supports the premise that speed limits established on the basis of the critical speed conform to the consensus of those who drive the road as to what speed is reasonable and safe. Speed limits set at or slightly below the critical speed provide police officers with a means of controlling the drivers who will not conform to what the majority of drivers consider to be a reasonable and prudent speed. The law provides that only when roadside development results in traffic conflicts and unusual conditions that are not readily apparent to the driver are speed limits somewhat below the 85'hpercentile warranted. The location of driveways and dwelling units on Alga Road were considered in the Engineering and Traffic Survey and it was determined not to be a condition that was not readily apparent to the drivers. In the one-year period from April 1,2001 to March 31, 2002, there has been one midblock collision in the road segment from El Camino Real to Alicante Road. This collision occurred 10 feet east of El Camino Real when a westbound vehicle rear-ended a vehicle stopped near the intersection in the number one traffic lane. The posted 50 mile per hour speed limit on the subject portion of Alga Road is justified by the results of the Engineering and Traffic Survey. The collision rate is very low and there are no roadside conditions not readily apparent to the driver to warrant additional speed zone reduction to 45 mile per hour. The City Council acted properly to set the Alga Road speed limit at 50 miles per hour as justified by the appropriate factors to avoid making use of radar unavailable for speed enforcement. Staff recommends that the City Council reaffirm their previous decision on this matter. If the City Council determines that a different speed limit is justified, staff should be directed to return with a new ordinance for adoption. FISCAL IMPACT: No impact if the 50 mile per hour prima facie speed limit is reaffirmed. If the speed limit is changed, there will be costs to change the posted speed limit signs. EXHIBITS: 1. Location Map. LOCATION MAP 50 MPH SPEED ZONE NOT TO SCALE PROJECT NAME ALGA ROAD EXHIBIT 50 MILE PER HOUR SPEED ZONE I W 8E SCOTI EVANS CAQLSB*O ENGlNffRlNG OfPf. 4/10/02 C: \lRAmC\sPEED ZDNE-ALGA ROAD.OWC rn S S 0 N U a, a, a cn .I I. 0 a, m cn L a, c 0 N 73 a, a, 3 0 L m 73 cn .- c\J cn a, c, a, S 0 N U a, a, a cn U m 2 r i( ?: I. 0 cn Q a> 0 . 0 c 0 L 0 a0 .- 5z "r m 3 m I-0 L4- cn g m 0 m - E L P- . 1 cn 0 m L in a, L cn c- U S a, m S rn II 0 OL .o rn> LLU 0 .". U a, a, Q I. 0 a, L CL a, m cn U c m rc a, d m c - 0 cn m a, L a, d m c 0 cn m a, L m 0 cn 4- r 0 4- om ,. CX 0 .- L2 m 0 a, -c.r I 7 -2 E . 0 W a, a, Q a> n --cI cn0 a,m c> I- .-. 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