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Home My WebLink About2011-06-06; Traffic Safety Commission; ; Approve an interim striping plan for La Costa Avenue from El Camino Real to Rancho Santa Fe RoadCITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: June 6, 2011 ITEMNO.6B LOCATION: INITIATED BY: La Costa Avenue from El Camino Real to Rancho Santa Fe Road City Council REQUESTED ACTION: Approve an interim striping plan for La Costa Avenue from El Camino Real to Rancho Santa Fe Road. BACKGROUND: Transportation staff has been working on traffic safety improvements to address safety concerns on La Costa A venue along the roadway section where residential units have direct access with limited comer site distance and vehicle speeds have negatively impacted the quality of life of the residents. These traffic safety improvements are specifically being designed to address issues cited as part of a recent court settlement. At the February 8, 2011 City Council meeting, staff presented a preliminary conceptual plan for La Costa A venue that proposed: • traffic signs warning drivers of upcoming residential driveways, • speed feedback signs to address vehicle speed; • a painted median prohibiting left tum movements to and from driveways, and • on-street parking prohibition to improve comer site distance at driveways. At the February 8 meeting Council approved the installation of the warning signs and speed feedback signs, but rejected the proposed on-street parking prohibition. Staff was directed to pursue some interim striping plan for La Costa A venue to address access to the residential units on the north side of La Costa A venue. Staff reviewed the use of a painted median without on- street parking prohibitions and decided to develop another alternative. The main reasons for this conclusion was the potential for low conformance to the left tum prohibitions (i.e., the painted median would not be a self-enforcing solution), and the issues related to limited comer site distance and vehicle speed were not addressed. As part of a related effort, staff embarked on the La Costa Avenue Improvement Project using a consultant team to "develop a cost effective, community-preferred plan to address traffic speeds and safety on La Costa A venue in a way that respects the residential character and arterial function of the roadway." The La Costa Avenue Improvement Project will use a series of public workshops to assist in the development of a vision for La Costa A venue. This project will work in coordination with city's general plan update and strive to meet the following core values included in the Envision Carlsbad process: • neighborhood revitalization, community design and livability • walking, biking, public transportation and connectivity • access to recreation and active, healthy lifestyles • sustainability Page I CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: ( continued) June 6, 2011 ITEMNO.6B A new conceptual plan was developed that improved comer site distance and retained on-street parking. The new "road diet" alternative reduces La Costa A venue to one through lane in each direction of traffic, and the existing second through lane of travel would be converted into a Class II bike lane. This road diet conceptual plan does not necessarily reduce vehicle speed, but the resulting one lane of traffic is a precursor to using the traffic measures that would significantly reduce vehicle speed (e.g., roundabouts). Under this proposal, the two-way left tum lane was left in its current configuration allowing left tum movement to and from the residential units. This road diet conceptual plan was presented to City Council at their March 22, 2011 meeting. Council agreed with the general concept and directed staff to present a formal interim striping plan for La Costa Avenue at the June 7, 2011 City Council meeting. Comments received at the April 28th La Costa A venue Improvement Plan public workshop raised concerns about potential traffic impacts of the proposed road diet striping plan. Staff also heard comments that the road diet alternative be limited to the area of La Costa A venue where residential units have direct access (i.e., the northern half of La Costa A venue traveling westbound from Romeria Street to Fairway Lane). Staff also started on the environmental review requirements and determined that California Environmental Quality Act (CEQA) supports a project that minimizes traffic impacts. That is, staff should select an alternative that directly resolves the safety issues and minimizes disruptions to traffic. Based on these public comments and CEQA law, staff developed the attached "hybrid" design that retains the current lane configuration eastbound and reduces La Costa A venue to one through lane westbound between Romeria Street and Fairway Lane. With this approach all roadway sections on La Costa Avenue with direct driveway access would have a bike lane that extends driver visibility approaching traffic and therefore increases the comer site distance. The only section of La Costa A venue that is altered is the segment with direct access to residential units on the north side of the road. This hybrid alternative is not expected to have any significant traffic impacts based on the preliminary level of service (LOS) results which are attached. RECOMMENDATION: Recommend that City Council approve an interim striping plan that: • maintains the current eastbound lane configuration on La Costa A venue between El Camino Real and Rancho Santa Fe Road; • reduces La Costa A venue to one lane in the westbound direction of travel west of Romeria Street to west of Fairway Lane by re-striping the existing Number 2 travel lane into a Class II bike lane; and • maintaining existing on-street parking, but allowing staff to prohibit on-street parking at select locations to improve comer site distance in response to resident requests. Page 2 CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: ( continued) June 6, 2011 NECESSARY CITY COUNCIL ACTION: ITEMNO.6B A resolution is expected to be adopted by the City Council to approve the interim striping plan for La Costa A venue. Attachments: La Costa A venue Hybrid Interim Striping Plan, La Costa A venue LOS Analysis Page 3 MEMORANDUM To: Doug Bilse, City of Carlsbad From: Arnold Torma, P.E., KOA Corporation JB14055 KOANo.: Date: May 26, 2011 Re: La Costa Avenue LOS Analysis Introduction The City of Carlsbad requested KOA Corporation to conduct intersection and segment analysis for the LA Costa Avenue Improvement Project. The results in this memorandum are presented for the following alternatives: I . Existing Condition 2. Painted Median 3. Road Diet 4. Hybrid Both ICU and HCM Analysis for intersections were conducted at the following three signalized intersections: I. La Costa Avenue and Viejo Castilla Way 2. La Costa Avenue and Romeria Street 3. La Costa Avenue and Cadencia Street Figure I below shows the geometry comparison of all the alternatives for the three intersections. Roadway segmental LOS analysis was conducted between the Shopping Center Driveway and Nueva Castilla Way for the above mentioned alternatives and the results presented in this memorandum. The the City's annual monitoring method and the "Florida DOT' techniques are used for the roadway segments. All the worksheets are provided in the Appendix. Finally, we offer a generalized estimate of the adequacy of potential roundabouts and their capacity using the ITE publication "Roundabouts: An Informational Guide". Findings Each of the three internal signalized intersections along the length of the project presently operate during peak hours at completely acceptable levels of service (A and B) and delay and continue to do so into the future conditions projected in this analysis and under all alternatives. Results were generally similar under both methods of analysis. The segmental analysis in both methods tended to produce results that were acceptable in the same locations, and it showed some undesirable levels of service at consistent locations. Specifically, when a lane is lost to go from two to one lane in the peak direction under the Road Diet and Hybrid alternatives the LOS tends to be E or F either under existing volumes or future volumes. The Florida DOT method is a bit more sensitive to the definition of the cross-section than the City's method (which simply depends on available lanes). Regarding potential roundabouts, the ITE publication cited above offers a generalized expectation of what the overall capacity of the facility might be based on ADT values (refer to their table in Exhibit 3-8 shown in the appendix). The typical maximum ADT capacity of a roundabout is 25,000 ADT in a balanced situation where side street traffic is equivalent to the major street volumes. As the imbalance increases (as is the situation on La Costa Ave) the overall capacity diminishes to around 18,000 to 19,000 where the side streets have only I 0% of the entering traffic. The existing traffic levels maximize around 18,000 presently and rise to around 22,000 in the future. Depending on where along La Costa Ave a roundabout is considered the volumes may decrease from these values somewhat. This suggests that in the imbalanced situation that is likely to exist on La Costa Ave we will be approaching the capacity of a typical roundabout assuming there is no diversion of traffic. More specific analysis can be provided once locations are selected for consideration and a conceptual layout is developed. 2 w La Costa Aveoue Road Diet Study I ! i II a I i ~ <'I 'l,· i ii of'~A\oe. ~ \ M ~ I . \ ~o (f,?f, ra%7<Pct KOA Corporation ,, ,~ -~ Q :g, ~ I Alternatives ,..Vieio castilla Way ii"' Romerla Street ,,.-Cadenda Street Existing It:. _i! !.__ 4 -1tF-~ itr 1' ➔ ..... ~;--~ +-. 4 Road Diet 1. ....21! :.: + :.: ~ ~ •r ;; t -..... Hybrid ~ Jt, ~ 4 JI! itr t ..,, ... ::: ..... • i~ *~ :n ~o ~ := ; -c, ~o := ~ ~ 0 z ) ' j Existing Intersection Condition at La Costa Avenue and Viejo Castilla Way ICU Methodology AM PM Alternatives ICU LOS ICU LOS Existing 0.383 A 0.335 A Painted Median 0.391 A 0.335 A Road Diet 0.569 A 0.531 A Hybrid 0.565 A 0.432 A HCM Methodology AM PM Alternatives Delay LOS Delay LOS Existing 7.5 A 7.4 A Painted Median 7.8 A 7.6 A Road Diet 9.6 A 9.4 A Hybrid 9.1 A 7.8 A Horizon Year Intersection Condition at La Costa Avenue and Viejo Castilla Way ICU Methodology AM PM Alternatives ICU LOS ICU LOS Horizon 0.442 A 0.386 A Painted Median 0.450 A 0.386 A Road Diet 0.666 B 0.626 B Hybrid 0.666 B 0.504 A 4 HCM Methodology AM PM Alternatives Delay LOS Delay LOS Horizon 8.0 A 8.5 A Painted Median 8.4 A 8.7 A Road Diet 9.9 A I I.I B Hybrid 11.3 B 9.7 A Existing Intersection Condition at La Costa Avenue and Romeria Street ICU Methodology AM PM Alternatives ICU LOS ICU LOS Existing 0.358 A 0.438 A Painted Median 0.364 A 0.443 A Road Diet 0.455 A 0.438 A Hybrid 0.358 A 0.438 A HCM Methodology AM PM Alternatives Delay LOS Delay LOS Existing 7.5 A 7.4 A Painted Median 7.8 A 7.6 A Road Diet 9.6 A 9.4 A Hybrid 9.1 A 7.8 A 5 r-1 Horizon Year Intersection Condition at La Costa Avenue and Romeria Street ICU Methodology AM PM Alternatives ICU LOS ICU LOS Horizon 0.415 A 0.512 A Painted Median 0.421 A 0.517 A Road Diet 0.534 A 0.512 A Hybrid 0.415 A 0.512 A HCM Methodology AM PM Alternatives Delay LOS Delay LOS Horizon 14.0 B 6.2 A Painted Median 14.7 B 7.2 A Road Diet 15.8 B 9.2 A Hybrid 14.0 B 6.2 A Existing Intersection Condition at La Costa Avenue and Cadencia Street ICU Methodology AM PM Alternatives ICU LOS ICU LOS Existing 0.423 A 0.423 A Painted Median 0.429 A 0.428 A Road Diet 0.423 A 0.423 A Hybrid 0.423 A 0.423 A 6 HCM Methodology AM PM Alternatives Delay LOS Delay LOS Existing 10.0 A 12.8 B Painted Median 10.6 B 15.5 B Road Diet 10.4 B 9.9 A Hybrid 10.0 A 12.8 B Horizon Year Intersection Condition at La Costa Avenue and Cadencia Street ICU Methodology AM PM Alternatives ICU LOS ICU LOS Horizon 0.485 A 0.488 A Painted Median 0.490 A 0.494 A Road Diet 0.485 A 0.488 A Hybrid 0.485 A 0.488 A HCM Methodology AM PM Alternatives Delay LOS Delay LOS Horizon 10.7 B 10.8 B Painted Median 11.6 B 11.8 B Road Diet 11.8 B 11.6 B Hybrid 10.7 B 10.8 B 7