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Home My WebLink About21 - Marguerite Avenue & Sandcastle Drive IntersectionFebruary 13, 2001 CITY COUNCIL AGENDA ITEM NO. 21 TO: Mayor and Members of the City Council FROM: Public Works Department SUBJECT: MARGUERITE AVENUE AT SANDCASTLE DRIVE SIGHT DISTANCE RECOMMENDATIONS: Select Option A to increase sight distance at the intersection of Marguerite Avenue and Sandcastle Drive and monitor the results. If the the results are unsatisfactory implement Option B and then Option C if necessary. Option A: Remove plants (other than groundcover) from the existing viewshed looking from Sandcastle Drive to the north and stripe a right -turn- only lane on northbound Marguerite Avenue. Option B: Remodel entry wall pilaster in addition to all the work in Option A. Option C: Construct approximately 50 feet of 3 — 4 foot high retaining wall, relocate the street light to behind the right -of -way, in addition to the work in Options A and B. 2. Direct staff to pursue the selected option with all affected property owners and the Harbor View Hills South Homeowners Association. DISCUSSION: The City Council directed staff to evaluate the sight distance at the intersection of Marguerite Avenue and Sandcastle Drive at their meeting of January 23, 2001. The evaluation was to include identifying methods of increasing the sight distance. The existing sight distance for drivers exiting from the community of Harbor Hills South is limited by several factors as shown on the attached photographs. Marguerite Avenue to the north is uphill and the road curves to the right. The alignment of the roadway provides a finite limit to the ability for motorists to see oncoming vehicles. In addition, the properties in Harbor View Hills South on Tiller Way have steep slopes from their back walls down to the Marguerite Avenue right -of -way. These slopes are landscaped and include plants which grow to several feet in height. Some of this landscaping SUBJECT: Marguerite Avenue at Sandcastle Drive Sight Distance February 13, 2001 Page 2 further limits the sight distance. Finally, there is an entry wall which has a pilaster at each end. Traffic Speeds In order to properly determine the desired sight distance, new radar spot -speed studies were obtained. Speeds were measured on Marguerite Avenue at Sandcastle Drive and up the hill closer to Harbor View Drive. The resulting eighty -fifth percentile speeds were found to be 32 MPH northbound and 34 MPH southbound at Sandcastle Drive and 41 MPH northbound and 40 MPH southbound south of Harbor View Drive. Over five hundred vehicles were clocked with the radar unit. In addition 24 -hour speed counts were obtained approximately midway between Harbor View Drive and Sandcastle Drive. The speeds on a daily basis were found to be very similar to the spot- speeds taken mid - morning. These results confirmed earlier observations that most southbound traffic is slowing for the STOP sign at Fifth Avenue by the time they reach the Sandcastle Drive intersection. Measured Sight Distance A survey instrument was used to determine the available sight distance for a driver's eye at three points as the driver moves forward on Sandcastle Drive. With the bumper at the limit line, the driver can see 340 feet up Marguerite Avenue. When the car moves up another 5 feet (so the bumper lines up with the curb) the sight distance increases to 415 feet and is limited by vegetation and the pilaster. If the driver pulls out another 5 feet (so the bumper is even with the bike lane stripe) the sight distance is 480 feet. Sight distance could be be increased by removing vegetation and the pilaster. Staff reviewed several resource documents to determine an appropriate sight distance given the speed on Marguerite Avenue. The Caltrans "Comer Sight Distance" was felt to be the most applicable. It calls for 440 feet for a speed of 40 MPH based upon a 7'h second maneuver time. Staff set a target of determining what improvements would provide 450 feet of sight distance. Improvement Options Option A would remove landscaping on the slope that limits the driver's view. For drivers stopped with their bumper at the limit line, this would provide approximately only 10 feet more sight distance because the entry wall and slope are the main view obstructions. For this reason staff recommends restriping Marguerite Avenue to provide a northbound right- turn -only lane at Sandcastle Drive. This will move the through traffic out farther into the street which will allow traffic on Sandcastle Drive to pull forward without interfering with traffic. If the driver pulls out only 5 feet beyond the curb line, their sight distance increases to 480 feet which exceeds the target distance of 450 feet. SUBJECT: Marguerite Avenue at Sandcastle Drive Sight Distance February 13, 2001 Page 3 Option B adds the removal of a portion of the pilaster on the entry wall. The area to be removed extends approximately one foot beyond the face of the wall. This would provide an estimated 20 feet of additional sight distance for a driver stopped at the limit line for a total of about 360 feet. The benefit is much greater for the driver who pulls forward, as most drivers currently are doing. It is estimated that it would cost $2500 to perform the work required to reconstruct the pilaster. Option C would add a short section of low retaining wall northerly of the existing entry wall. It would be constructed as an extension of the entry wall. With just the pilaster remodel, the slope becomes the limiting factor for the sight distance. By installing the wall extension, the slope area is removed and sight distance is increased to approximately 550 feet for the driver who pulls forward from the limit line. This option also includes the relocation of the existing street light so that maximum, continuous visibility is provided. The estimated cost for this alternative is $18,000. While the slope along Marguerite Avenue belongs to the individual property owners with addresses on Tiller Way, it appears to be maintained by the Association. Options involving the entry wall and /or slope planting will need to be approved by the Association. Option C will require agreement by the owners of the first two lots on Tiller Way. Option A is recommended because it improves the sight distance with the least disturbance of existing improvements and is a good first phase. If it works, no further action is required. Options B and C can be implemented in the furture if needed. PIC WORKARTMENT Don Webb, Director Ri hard M. Edmonst n Transportation and Development Services Manager Attachments: Photographs • • SUBJECT: Marguerite Avenue at Sandcastle Drive Sight Distance February 13, 2001 Page 4 VIEW WITH FRONT BUMPER AT LIMIT LINE • VIEW WITH FRONT BUMPER 5 FEET IN FRONT OF LIMIT LINE • • SUBJECT: Marguerite Avenue at Sandcastle Drive Sight Distance February 13, 2001 Page 5 VIEW WITH FRONT BUMPER AT BICYCLE LANE LINE e Cu 2 1 3E r 4k SE 0 c u go, t c d P 21 j2 0 7 "RECEI ED AFTE GENT_ I D1 ROBERT D CURCI RECEIVED 998 Sandcastle Driyg Corori del Near, CA 92625 FEB OFFICE OF THE CITY CLERA CITY OF NEWPORT BEACH February 9 2001 The Honorable Mayor Members of the City Council 330 Newport Blvd Newport Beach CA 92663 RE February 13 2001 Agenda Item #21 Marguerite @ Sandcastle Drive Intersection Sight Line P oblem Dear Mayor and Council A review of the current Staff Report calls out in Option A that the entry wall and the slope are the main obstructions creating the site distance problem I herefore I would like to respectfully request that the City Council implements both Option A and B at this time Option A on its own does not deal with the f-ntry wall Therefore implementing A and B now would address both the main obstructions Perhaps enough staff and Council time has been expended on this and instead of coming back to add B later it would be more time and cost effective to do A and B now In addition consideration of a customized relocated forward or a wider painted limit line encouraging drivers to pull forward might also be helpful Yours truly S Robert D Curc RDC rls