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HomeMy WebLinkAboutNB 5 LEFT TURN LANE 02-17-87 ENDA ~0./7. ~,~, 2-17-87 r Inter- Corn FEBRUARY I , 19 7 TO: FROM: SUBJECT: WILLIAI~ HUSTON, CITY HANAGER PUBLIC WORKS DEPARTliENT/ENGINEERING OIVISION NEWPORT AVENUE LEFT TURN LANE STORAGE CAPACITIES RECOMMENDATION: For the City Council meeting of February 17, 1987. Review and prioritize desired modifications for consideration Capital Improvement Budget. in the 1987-88 BACKGROUND: At the request of the City Council, the City's Traffic Consultant has completed a study of'storage capacities of the Newport Avenue left turn lanes between Irvine Boulevard and Walnut Avenue. This study consisted of two s~parate surveys, one in the a.m. peak hour and one in the p.m. peak hour. Observations were completed for each left turn movement within the study section, Comparisons were made between each existing left turn lane length and the maximum observed demands to determine requirements for immediate and future needs. DISCUSSION: ~ach segment of Newport Avenue wilQ be discussed below and will include suggested measures for improvement. Irvine Boulevard to Holt Avenue The northbound left turn (NBLT) movement from Newport Avenue to westbound Irvine Blvd. is providing adequate service at this time. As the NBLT demand increases in the future, a dual left turn movement could be implemented. This dual left turn movement would require median island modification. No problems were noted for the southbound left turn (SBLT)movement from southbound Irvine Blvd. to eastbound Irvine Blvd. Holt Avenue to First Street The existing NBLT movement from Newport Avenue to westbound Holt Avenue does not have sufficient capacity to service existing traffic volumes. Dual left turn movements could be implemented and would require the following: A. Total modification of the landscape median island between Holt Avenue and First Street. FEBRUARY 10, 1987 PAGE TWO b. Maintain the prohibited on-street parking on the westerly side of Newport Avenue between Holt Avenue and First Street. Ce Removal of on-street parking along the westerly side of Newport Avenue both 200 ft. north of Holt Avenue and 200 ft. south of First Street. d. Removal of parking along the northeasterly side of Holt Avenue west of Newport Avenue. An alternative to this measure would be to remove all landscaping from the median island and construct a four foot wide median island with embossed concrete. This would allow the NBLT to be lengthened and the SBLT at First Street to be shortened. This alternative would not be as effective in the long term but certainly workable as an interim measure. Preliminary cost estimate for this work is $28,000.00. First Street to Main Street The SBLT storage lane is adequate for existing and projected demands. The NBLT movement from Newport Avenue to westbound First Street is inadequate and requires modification. The suggested modification would be to extend the left turn storage lane and landscape median island southerly which would result in the following impacts: Full time prohibition of left turn movements to and from the Bank of America/Burger King driveway on Newport Avenue. be Full time prohibition of left turn movements to and from the northerly driveway of the Medical Center complex to 13362-13422 Newport Avenue. Preliminary cost estimate for this work is $42,600.00. Main Street to E1 Camino Real All left turn storage lanes adjacent to the Carver Development are operating at acceptable levels with the exception of the NBLT from Newport Avenue to westbound Main Street. This is a result of left turn access being permitted to and from Andrews Street. Any closure of the median across Andrews St. could create a hardship to the residents of Andrews St. as well as the service station at the northeasterly corner of Andrews St.. and Newport Ave. The use of dual NBLT lanes were studied and found not to be acceptable due to the acute angle of the west leg of the intersection (i.e., for westbound Main Street). At the current time, staff does not feel that there is a solution to the deficiency at Main St. other than the closure of Andrews St. As vehicular activity at the Carver Development increases, staff will continue to re-evaluate the remaining intersections between Main Street and E1 Camino Real. FEBRUARY 10, 1987' PAGE THREE E1Camino Real to Mitchell Avenue The storage for NBLT from Newport Avenue to westbound E1 Camino Real was also found to be deficient. This deficiency could be corrected by extending the existing left turn storage lane and the raised median island southerly to E1 Camino Way/I-5 which would result in the following impacts: a. Full time prohibition of left turn movements to and from the Unocal Service Station. The freeway widening will remove approximately 50% of this station in 1989-90. b. Full time prohibition of left turn movements to and from the Sizzler Restaurant. The freeway widening is anticipated to remove some of the parking but the business is scheduled to remain in tact. The left turn movements under the freeway to both E1Camino Way and Nisson Road will be modified and improved with the freeway widening project in 1989-90. E1 Camino Way will be deleted with respect to' two-way traffic and converted to a westbound on-ramp to I-5. The SBLT storage lane from Newport Avenue to eastbound Mitchell Avenue is deficient. This deficiency can be corrected by extending the storage lane and landscaped medians northerly which would result in the following impacts: a. Full time prohibition of left turn movements to and from the drive-in dairy and the Taco Bell Restaurant. Preliminary cost estimate for the work at both intersections is $50,500.00. Mitchell Avenue to Walnut Avenue The SBLT storage lane from Newport Avenue to eastbound Walnut Avenue is deficient. This deficiency can be accommodated with the use of dual left turn movements. The implementation of dual left turns would require the removal of on-street parking on both sides of Newport Ave. and for a distance of 300 feet either side of Walnut Avenue. Preliminary cost estimate for these modifications is $8,500.00. The total estimated cost for all locations is $129,600.00. These figures are very preliminary and require refinement for budgeting purposes. An additional alternative to these above mentioned modifications would be the total removal of the landscaped medians at the indicated locations and the replacement with asphaltic concrete pavement and pavement markings. This alternate would substantially reduce the cost of the suggested modifications. FEBRUARY 10, 1987 PAGE FOUR Due to the extensive cost and neighborhood impacts of the suggested modifications, it is recommended that the City Council review and prioritize the desired modifications for conside'ration in the 1987-88 Capital Improvement Budget. As a part of the budget process, staff can identify potential sources of funding that may be available to the City. Director of Public Works/City Engineer BL:jm