CITY OF LA MESA MIXED-USE OVERLAY ZONE PROJECT La Mesa, California August 15, 2007 Revised January 16, 2008

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1 TRAFFIC IMPACT STUDY CITY OF LA MESA MIXED-USE OVERLAY ZONE PROJECT La Mesa, California August 15, 2007 Revised January 16, 2008 Prepared for: DUDEK & ASSOCIATES 605 Third Street Encinitas, California LLG Ref Prepared by: Raul Armenta Transportation Engineer III Under the Supervision of: John Boarman, P.E. Principal

2 TABLE OF CONTENTS SECTION PAGE 1.0 Introduction Project Description Project Description Existing Conditions Existing Street System Existing Traffic Volumes Area Transit Pedestrian Systems Bicycle Systems Analysis Approach and Methodology Traffic Analysis Approach Traffic Analysis Methodology Street Segments Signalized Intersections Significance Criteria Road Segments Intersections Project Traffic Project Traffic Generation Project Traffic Distribution & Assignment Cumulative Projects Existing Street Segments Operations Horizon Year Analysis Horizon Year Conditions Horizon Year Traffic Volumes Horizon Year Street Segment Operations Horizon Year Street Segment Operations Without the Mixed-Use Overlay Horizon Year Street Segment Operations With the Mixed-Use Overlay Alternative Analysis Horizon Year Conditions Horizon Year Traffic Volumes LINSCOTT, LAW & GREENSPAN, engineers LLG Ref i Mixed-Use Overlay Zone Project N:\1747\text\1747 Revised Report.doc

3 Reduced Project Alternative No Project Alternative Horizon Year Street Segment Operations Horizon Year Street Segment Operations with Reduced Mixed-Use Overlay Horizon Year Street Segment Operations with the Current General Plan Peak Hour Intersection Analysis Existing Peak Hour Intersection Levels of Service Horizon Year Peak Hour Intersection Levels of Service Horizon Year Peak Hour Intersection Levels of Service Without the Mixed-Use Overlay Horizon Year Peak Hour Intersection Levels of Service With the Mixed-Use Overlay Construction Traffic Review Significance of Impacts and Mitigation Measures LINSCOTT, LAW & GREENSPAN, engineers LLG Ref ii Mixed-Use Overlay Zone Project N:\1747\text\1747 Revised Report.doc

4 APPENDICES APPENDIX A. Street Segment Data B. County of San Diego Roadway Classification Information C. Trip Generation and Land Use Information (Baseline and 2030) D. SANDAG Year 2030 Forecast Model With and Without the Project E. Existing intersection manual count sheets F. Existing peak hour intersection analysis sheets G. Horizon Year without Mixed-Use Overlay peak hour intersection analysis sheets H. Horizon Year with Mixed-Use Overlay peak hour intersection analysis sheets LINSCOTT, LAW & GREENSPAN, engineers LLG Ref iii Mixed-Use Overlay Zone Project N:\1747\text\1747 Revised Report.doc

5 LIST OF FIGURES SECTION FIGURE # PAGE Figure 1 1 Vicinity Map 2 Figure 2 1 Mixed-Use Overlay Project Area Map 4 Figure 3 1 Existing Conditions Diagram 8 Figure 3 2 Existing Traffic Volumes (ADT s) 9 Figure 6 1 Mixed-Use Overlay Project Area & TAZ s 15 Figure 9 1 Horizon Year Without Project Traffic Volumes (ADT s) 21 Figure 9 2 Horizon Year With Project Traffic Volumes (ADT s) 22 Figure 10 1 Horizon Year With Reduced Project Traffic Volumes (ADT s) 25 Figure 10 2 Horizon Year No Project Traffic Volumes (ADT s) 26 Figure 11 1 Existing Traffic Volumes (AM/PM Peak Hour Volumes) 30 Figure 11 2 Horizon Year Without Project Traffic Volumes (AM/PM Peak Hour Volumes) 31 Figure 11 3 Horizon Year With Project Traffic Volumes (AM/PM Peak Hour Volumes) 32 LIST OF TABLES SECTION TABLE # PAGE Table 4 1 Level Of Service Thresholds For Signalized Intersections Table 8 1 Existing Street Segment Operations Table 9 1 Horizon Year Street Segment Operations Table 10 1 Alternative Horizon Year Street Segment Operations Table 11 1 Existing Intersection Operations Table 11 2 Horizon Year Intersection Operations LINSCOTT, LAW & GREENSPAN, engineers LLG Ref iv Mixed-Use Overlay Zone Project N:\1747\text\1747 Revised Report.doc

6 TRAFFIC IMPACT STUDY MIXED-USE OVERLAY ZONE PROJECT REVITALIZATION PROJECT La Mesa, California August 15, 2007 Revised January 16, INTRODUCTION Linscott, Law & Greenspan, Engineers (LLG) has been retained by Dudek & Associates to assess the potential traffic impacts associated with the City of La Mesa Mixed-use Overlay Zone Project. The project allows for a mix of commercial and residential development at densities up to 40 dwelling units per acre. The transit corridors along El Cajon Boulevard, La Mesa Boulevard, University Avenue, Baltimore Drive south of I-8, and in the neighborhood around the Spring Street Trolley Station were designated as Mixed Use Urban areas of the City. The project vicinity is shown in Figure 1 1. The traffic analysis presented in this report encompasses the following: Project description Existing conditions assessment Analysis Approach and Methodology Significance Criteria Analysis of Existing Conditions Project traffic generation/distribution/assignment Horizon Year capacity analyses with and without the Mixed-Use Overlay Zone Significance of Impacts and Mitigation Conclusions LINSCOTT, LAW & GREENSPAN, engineers LLG Ref Mixed-Use Overlay Zone Project N:\1747\text\1747 Revised Report.doc

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8 2.0 PROJECT DESCRIPTION 2.1 Project Description The proposed Mixed-Use Overlay Zone is designed to add regulations and standards to the zoning code to implement the objectives of the General Plan. The Mixed-Use Overlay Zone would guide the development of mixed-use projects on parcels zoned for residential and commercial use along University Avenue, El Cajon Boulevard, La Mesa Boulevard, and in the vicinity of the Spring Street Trolley Station at the intersection of Spring Street and Palm Avenue. New development would be subject to development standards of the new Mixed-Used Overlay Zone. As part of the proposed Mixed-Use Overlay Zone, a conditional use permit would be required for all new automobile gas stations, certain other automobile uses, and drive-thru sales. Current limits on the amount of retail area on the ground floor in the residential zone would be removed. Residential uses would be permitted on the ground floor of properties in the commercial zone as long as development standards of the Mixed-Use Overlay zone are followed. The proposed Mixed-Use Overlay Zone would also accommodate an increase in the maximum allowable residential dwelling units per acre in the residential zone. The allowable residential units per acre would increase from 18 to 23 dwelling units per acre to 40 dwelling units per acre, which would be consistent with General Plan policies. Additionally, the development standards in the Mixed-Use Overlay Zone would increase the potential for the development of a pedestrian realm along the three corridors and near the Spring Street Trolley Station. The proposed overlay zone would employ development standards and design guidelines to facilitate the development of pedestrian areas and streetscape along the street edge creating a more walkable and attractive pedestrian environment, which would bolster the goals of the mixed-use designation in the General Plan. The proposed Mixed-Use Overlay Zone itself does not require the City, developers, or others to construct mixed-use projects, but merely determines how the City will accommodate such projects as proposed. The exact locations(s) of the site(s) that would be developed are therefore not analyzed in this document. Figures 2 1 depicts the Mixed-Use Overlay Zone area. The study area for this project encompasses areas of potential impact related to the project. The scope of the study area was developed under the direction of City staff, and a working knowledge of the local transportation system. LINSCOTT, LAW & GREENSPAN, engineers LLG Ref Mixed-Use Overlay Zone Project N:\1747\text\1747 Revised Report.doc

9 ,000 2,000 Feet Figure 1-2 Mixed-Use Overlay Project Area Map CITY OF LA MESA MIXED-USE OVERLAY ZONE PROJECT 8 JAC KS O N DRIVE EL CAJ ON BLVD LA MESA BLVD BALTIMORE AVE LA MESA BLVD SPRING STREET 70TH STREET UNIVERSITY AVENUE REV. 7/10/07 N:\1747\GIS\Mixed-Use Overlay Project Area Map

10 3.0 EXISTING CONDITIONS 3.1 Existing Street System Effective evaluation of the traffic conditions associated with the proposed development requires an understanding of the existing transportation system in the project study area. Existing transportation conditions in the study area include roadway geometrics, traffic control, and daily traffic flow. Figure 3 1 shows the existing conditions and the lane geometry at the three key study area intersections. City of La Mesa General Plan Circulation Element According to the City of La Mesa General Plan Circulation Element, Arterials should be between 58 to 82 feet wide in 78 to 102 feet of Right of Way (R/W), providing up to four through lanes and sidewalks with an optional median divider, bicycle lanes and curbside parking. Collector (Local) roadways should be between 40 to 64 feet wide in 60 to 84 feet of Right of Way (R/W), providing two through lanes, curbside parking and sidewalk with and optional, bicycle lanes painted median or removal of curbside parking. El Cajon Boulevard El Cajon Boulevard is an east-west facility classified as a four-lane Arterial in the City of La Mesa Circulation Plan Map and runs from west of the City limits to Interstate 8 through the study area. El Cajon Boulevard is currently constructed as a four-lane roadway with a raised median and curbside parking is provided intermittently along both sides of the roadway. Bus stops are provided with a posted speed limit of 35 mph. Traffic is controlled by signals and additional turn lanes are provided at major intersections along the roadway. Land uses in the vicinity of El Cajon Boulevard are a mix of office, commercial and residential. University Avenue University Avenue is generally an east-west facility classified as a four-lane Arterial in the City of La Mesa Circulation Plan Map up to the University Avenue / Spring Street intersection and a twolane Arterial from Spring Street to La Mesa Boulevard (east). University Avenue west of the City Limits to Spring Street is currently constructed as a four-lane roadway with a raised median and the portion of University Avenue from Spring Street to La Mesa Boulevard (west) currently is constructed as a two lane undivided roadway with a two-way left-turn lane and bike lanes. University Avenue traffic is controlled by signals and additional turn lanes are provided at major intersections. University Avenue provides curbside parking along both sides of the roadway with. bus stops and with a posted speed limit of 35 mph. Land uses in the vicinity of University Avenue are a mix of office, commercial and residential. La Mesa Boulevard La Mesa Boulevard is generally an east-west facility classified as a two-lane local collector from El Cajon Boulevard to University Avenue (east) and a four-lane arterial from University Avenue (east) to east of Grossmont Boulevard on the City of La Mesa Circulation Plan Map. La Mesa Boulevard LINSCOTT, LAW & GREENSPAN, engineers LLG Ref Mixed-Use Overlay Zone Project N:\1747\text\1747 Revised Report.doc

11 from El Cajon Boulevard to University Avenue (west) is currently constructed as a two-lane roadway with bus stops and a posted speed limit of 25 mph. There is currently curbside parking along both sides of the roadway up to Acacia Avenue and then changes to diagonal curbside parking along the south side of La Mesa Boulevard up to Spring Street. It changes to diagonal curbside parking on both sides of the roadway up to Cypress Street and then back to curbside parking along both sides of the roadway up to University Avenue (east). La Mesa Boulevard from University Avenue (east) to east of Grossmont Boulevard is currently constructed as a four-lane roadway with a raised median or a two-way left-turn lane and curbside parking is provided intermittently along both sides of the roadway. Bus stops are provided with a posted speed limit of 35 mph. Traffic is controlled by signals and additional turn lanes are provided at major intersections along the roadway. Land uses in the vicinity La Mesa Boulevard are a mix of office, commercial and residential. Spring Street Spring Street is a north-south facility classified as a four-lane arterial roadway in the City of La Mesa Circulation Plan Map and runs from south of the Interstate 8 to just south of the State Highway 94 through the study area. Spring Street is currently constructed as a four-lane divided roadway with a two-way left-turn lane with curbside parking prohibited. Traffic is controlled by signals and additional turn lanes are provided at major intersections along the roadway. Land uses in the vicinity of Spring Street are a mix of office, commercial and residential. 70 th Street 70th Street is a north-south facility classified as a four-lane arterial roadway on the City of La Mesa Circulation Plan Map and runs from south of the Interstate 8 to University Avenue. 70th Street is currently constructed as a four-lane divided roadway from Interstate 8 to El Cajon Boulevard and a two-lane divided roadway with a two-way left-turn lane with curbside parking provided on both sides of the roadway and bike lanes south of El Cajon Boulevard. Land uses in the vicinity of 70th Street are a mix of office, commercial and residential. Baltimore Drive Baltimore Drive is a north-south facility classified as a four-lane arterial roadway in the City of La Mesa Circulation Plan Map and runs from University Avenue north through the study area. Baltimore Drive is currently constructed as a four-lane undivided roadway with curbside parking prohibited from University Avenue to El Cajon Boulevard and a divided roadway north of El Cajon Boulevard with bike lanes provided and curbside parking prohibited. Traffic is controlled by signals and additional turn lanes are provided at major intersections along the roadway. Land uses in the vicinity of Baltimore Drive are a mix of office, commercial, and residential. 3.2 Existing Traffic Volumes The most recent available existing street segment Average Daily Traffic (ADT) volumes were provided by the City of La Mesa. Figure 3 2 shows the existing daily traffic volumes. Appendix A contains copies of the segment data. LINSCOTT, LAW & GREENSPAN, engineers LLG Ref Mixed-Use Overlay Zone Project N:\1747\text\1747 Revised Report.doc

12 3.3 Area Transit The project site is well served by transit. An on-site transit center is located in the west side of the site provides regional and community service. This transit station serves five bus routes (bus routes 1, 7, 14, 854, and 855) and the Grossmont Center and La Mesa Boulevard trolley stations (trolley lines orange and green). 3.4 Pedestrian Systems The City of La Mesa has developed a Walkability Plan with the purpose of making the City of La Mesa a more walkable community; the plan sets the stage for achieving the General Plan vision of creating a community in which residents of all ages and abilities feel that it is safe, comfortable, convenient, efficient and welcoming to walk not only for recreation purposes but also for utility and transportation. The Walkabilty Plan recommends pedestrian improvements at the key intersections along the University Avenue and El Cajon Boulevard segments to make the crossing more comfortable. The proposed overlay zone would employ development standards and design guidelines to facilitate the development of pedestrian areas and streetscape along the street edge creating a more walkable and attractive pedestrian environment. 3.5 Bicycle Systems Existing bike facilities within the study include University Avenue between Spring Street and La Mesa Boulevard and 70 th Street north of University Avenue. As mentioned before, the City has developed the Walkabilty Plan not only to facilitate pedestrians but also to encourage bicyclists. The Walkability Plan recommends new routes along El Cajon Boulevard and University Avenue segments and specific improvements at the key intersections along the El Cajon Boulevard and University Avenue segments to improve the mobility. LINSCOTT, LAW & GREENSPAN, engineers LLG Ref Mixed-Use Overlay Zone Project N:\1747\text\1747 Revised Report.doc

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15 4.0 ANALYSIS APPROACH AND METHODOLOGY 4.1 Traffic Analysis Approach The project is an overlay zone which will add regulations and standards to the zoning code to implement the objectives of the General Plan. No development is proposed as part of this project. The standard of practice in traffic engineering to analyze such projects for potential traffic impacts is to determine if significant impacts would occur in the 20-year horizon time frame (i.e. Year 2030), since the development per the zoning would occur over a long period. The source of Year 2030 volumes in the San Diego region is the SANDAG traffic model. Furthermore, the standard of practice to analyze potential impacts in 2030 is to assess street segments on an Average Daily Traffic (ADT) basis. However, in addition to analyzing street segments, a peak hour analysis was conducted at three key study area intersections. The approach for this traffic study is to code the overlay zone into the SANDAG traffic model and run the model to output Year 2030 ADTs. These future traffic volumes are then analyzed to determine the predicted Year 2030 Level of Service on the key roadways in the study area. If the future LOS is within City standards minimum (LOS D), no significant impact is calculated. If the future LOS exceeds City standards, a significant impact is calculated and mitigation recommended. Cumulative traffic is fully included in the analysis since the SANDAG model assumes general buildout of the City of La Mesa and other neighboring cites (such as the City of El Cajon, the City of Lemon Grove and the City of San Diego) per their individual General Plans. 4.2 Traffic Analysis Methodology Level of service (LOS) is the term used to denote the different operating conditions which occur on a given roadway segment under various traffic volume loads. It is a qualitative measure used to describe a quantitative analysis taking into account factors such as roadway geometries, signal phasing, speed, travel delay, freedom to maneuver, and safety. Level of service provides an index to the operational qualities of a roadway segment or an intersection. Level of service designations range from A to F, with LOS A representing the best operating conditions and LOS F representing the worst operating conditions Street Segments Given that the City of La Mesa does not have a street classification table, the street segment analysis is based upon the comparison of daily traffic volumes (ADTs) to the County of San Diego s Standard Street Classification Table. This table provides segment capacities for different street classifications, based on traffic volumes and roadway characteristics. The County of San Diego Roadway Classification information is attached in Appendix B. LINSCOTT, LAW & GREENSPAN, engineers LLG Ref Mixed-Use Overlay Zone Project N:\1747\text\1747 Revised Report.doc

16 4.2.2 Signalized Intersections Signalized intersections were analyzed for the weekday AM and PM peak hour conditions. Average vehicle delay was determined using the methodology found in Chapter 16 of the 2000 Highway Capacity Manual (HCM), using the Traffix (version 7.7) computer software. The delay values (represented in seconds) were qualified with a corresponding intersection level of service. Table 4 1 summarizes the delay thresholds for signalized intersections. TABLE 4 1 LEVEL OF SERVICE THRESHOLDS FOR SIGNALIZED INTERSECTIONS Average Control Delay Per Vehicle (Seconds/Vehicle) Level Of Service 0.0 < 10.0 A 10.1 to 20.0 B 21.1 to 35.0 C 35.1 to 55.0 D 55.1 to 80.0 E > 80.0 F Source: Highway Capacity Manual, LINSCOTT, LAW & GREENSPAN, engineers LLG Ref Mixed-Use Overlay Zone Project N:\1747\text\1747 Revised Report.doc

17 5.0 SIGNIFICANCE CRITERIA The City of La Mesa does not have a published traffic significance criteria. Since the City does not have a significance criteria, the criteria used was based on the County of San Diego document Guidelines for Determining Significance, December 5, Road Segments Pursuant to the County s criteria, a new development must provide improvements or other measures to mitigate traffic impacts to avoid: Reduction in LOS below "D" for off-site and on-site abutting Circulation Element roads; and "Significantly impacting congestion" on roads that operate at LOS "E" or "F". The County has created the following guidelines to evaluate likely traffic impacts of a proposed project for road segments to determine whether the development would "significantly impact congestion" on the referenced LOS E and F roads. The guidelines are summarized in the table below in this report. The thresholds in the table are based upon average operating conditions on County roadways. It should be noted that these thresholds only establish general guidelines, and that the specific project location must be taken into account in conducting an analysis of traffic impact from new development. If LOS D or better is calculated, no significant impact is determined. If LOS E or F is calculated, the following table is used to determine if the project s impact is significant. MEASURES OF SIGNIFICANT PROJECT IMPACTS TO CONGESTION ON ROAD SEGMENTS ALLOWABLE INCREASES ON CONGESTED ROAD SEGMENTS Level of Service Two-Lane Road Four-Lane Road Six-Lane Road LOS E 200 ADT 400 ADT 600 ADT LOS F 100 ADT 200 ADT 300 ADT 5.2 Intersections Traffic volume increases from public or private projects that result in one or more of the following criteria will have a significant traffic volume or level of service traffic impact on a signalized intersection: The additional or redistributed ADT generated by the proposed project will significantly increase congestion on a signalized intersection currently operating at LOS E or LOS F, or will cause a signalized intersection to operate at a LOS E or LOS F as identified below. LINSCOTT, LAW & GREENSPAN, engineers LLG Ref Mixed-Use Overlay Zone Project N:\1747\text\1747 Revised Report.doc

18 MEASURES OF SIGNIFICANT PROJECT IMPACTS TO CONGESTION ON INTERSECTIONS ALLOWABLE INCREASES ON CONGESTED INTERSECTIONS Level of service LOS E LOS F Signalized Delay of 2 seconds Delay of 1 second, or 5 peak hour trips on a critical movement General Notes: a. A critical movement is one that is experiencing excessive queues. b. By adding proposed project trips to all other trips from a list of projects, these same tables are used to determine if total cumulative impacts are significant. If cumulative impacts are found to be significant, each project that contributes any trips must mitigate a share of the cumulative impacts. c. The County may also determine impacts have occurred on roads even when a project s traffic or cumulative impacts do not trigger an unacceptable level of service, when such traffic uses a significant amount of remaining road capacity. It should be noted that the City of La Mesa has a Level of Service discussion in the City s General Plan Circulation Element which states that when a traffic analysis indicates that the level of service (LOS) reaches D or below, the City will determine what improvements are needed. The City of La Mesa will require individual projects within the overlay zone to complete a traffic study to ensure that City policies are met. LINSCOTT, LAW & GREENSPAN, engineers LLG Ref Mixed-Use Overlay Zone Project N:\1747\text\1747 Revised Report.doc

19 6.0 PROJECT TRAFFIC 6.1 Project Traffic Generation Trip generation estimates for the with and without mixed-use overlay zone development were based on the San Diego Association of Governments (SANDAG) model. City staff provided SANDAG with their General Plan land uses which includes the Mixed-Use Overlay Zone. The SANDAG model forecasts traffic volumes in the year 2030 time frame. To assess the trip generation for the without proposed mixed-use overlay condition, the area for the overlay was divided into traffic analysis zones (TAZ s) and the land use information designated under the baseline condition was replaced in the 2030 model. A specific model run without the overlay was completed. Figure 6 1 shows the project area in relation to the SANDAG TAZ s. Land uses within the TAZ s that were identified as being a part of the project overlay were accounted for in the analysis. In some instances, the project overlay was not completely covered by a particular TAZ; in those cases an assessment was undertaken to estimate the appropriate project land uses for the project. Appendix C contains the trip generation and land use information by TAZ for the baseline and 2030 conditions. 6.2 Project Traffic Distribution & Assignment The project trip distribution and assignment process was based on a gravity model provided by SANDAG. The model evaluates the distribution based on likely travel routes and the directional orientation of traffic to and from the project area. Trip distribution is heavily influenced by the geographical location of the site, the location of surrounding uses, and the proximity to the regional freeway system. LINSCOTT, LAW & GREENSPAN, engineers LLG Ref Mixed-Use Overlay Zone Project N:\1747\text\1747 Revised Report.doc

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21 7.0 CUMULATIVE PROJECTS Traffic conditions have been evaluated using the SANDAG Series 10 Model (Year 2030). The forecast Model contains planned development, as outlined by the City of La Mesa General Plan and the General Plans of other cities near the City of La Mesa. In an effort to accurately and conservatively estimate cumulative traffic conditions, the Model was reviewed in cooperation with SANDAG and LLG Engineers. All cumulative projects were assumed completed and fully occupied by the Year It is understood that much of the development associated with the overlay zone will be phased with an opening day after the Year 2030; however, to be conservative, the entire project was incorporated in the Model. LINSCOTT, LAW & GREENSPAN, engineers LLG Ref Mixed-Use Overlay Zone Project N:\1747\text\1747 Revised Report.doc

22 8.0 EXISTING STREET SEGMENTS OPERATIONS Existing street segment analyses were conducted for roadways in the study area. Table 8 1 reports existing street segment operations on a daily basis. The majority of street segments operate at Level of Service D or better for existing conditions. The segments of 70 th Street both north and south of El Cajon Boulevard are calculated to currently operate at LOS E. LINSCOTT, LAW & GREENSPAN, engineers LLG Ref Mixed-Use Overlay Zone Project N:\1747\text\1747 Revised Report.doc

23 TABLE 8 1 EXISTING STREET SEGMENT OPERATIONS Roadway Segment # of Lanes Functional Classification Capacity EXISTING (LOS E) a ADT b V/C c LOS d El Cajon Boulevard 70 th Street to 73 rd Street 4 Arterial 37,000 19, B 73 rd Street to Comanche Drive 4 Arterial 37,000 19, B Comanche Drive to Parks Avenue 4 Arterial 37,000 19, B Parks Avenue to La Mesa Boulevard 4 Arterial 37,000 19, B La Mesa Boulevard to Guava Avenue 4 Arterial 37,000 19, B Guava Avenue to Baltimore Drive 4 Arterial 37,000 19, B Baltimore Drive El Cajon Boulevard to University Avenue 4 Arterial 37,000 28, C Spring Street I-8 On/Off Ramps to University Avenue 4 Arterial 37,000 18, B University Avenue to La Mesa Boulevard 4 Arterial 37,000 20, B University Avenue 70 th to Massachusetts Ave 4 Arterial 37,000 21, B Massachusetts Ave to Yale Avenue 4 Arterial 37,000 18, B Yale Avenue to Lowell Street 4 Arterial 37,000 20, B Lowell Street to Parks Avenue 4 Arterial 37,000 20, B Parks Avenue to Dale Avenue 4 Arterial 37,000 21, B Dale Avenue to La Mesa Blvd (west) 4 Arterial 37,000 21, B La Mesa Blvd (west) to Baltimore Drive 4 Arterial 37,000 24, B Baltimore Drive to Spring Street 4 Arterial 37,000 13, A Spring Street to La Mesa Blvd (east) 3 Town Collector 19,000 7, C La Mesa Boulevard El Cajon Boulevard to University Avenue (west) 2 Local Collector 16,200 5, C University Avenue (east) to Jackson Drive 4 Arterial 37,000 11, A Jackson Drive to Grossmont Drive 4 Arterial 37,000 8, A 70 th Street North of El Cajon Boulevard 4 Arterial 37,000 34, E South of El Cajon Boulevard 3 Town Collector 19,000 18, E Notes: a. Capacity based on County of San Diego Roadway Standards. b. Average Daily Traffic. c. Volume to Capacity ratio d. Level of Service. LINSCOTT, LAW & GREENSPAN, engineers LLG Ref Mixed-Use Overlay Zone Project N:\1747\text\1747 Revised Report.doc

24 9.0 HORIZON YEAR ANALYSIS 9.1 Horizon Year Conditions In assessing the potential impacts of the proposed Mixed-use Overlay Zone Project, it was necessary to study the with and without project conditions. 9.2 Horizon Year Traffic Volumes Horizon Year traffic volumes with and without the overlay were forecasted for the study area using the SANDAG Series 10 Model. In order to provide a slightly conservative analysis the With Project forecast volumes were increased by 10%. Ten percent was chosen since it promises a reasonable factor of safety given the amount of assumptions inherent in a long-term analysis. The Year 2030 Without Project traffic volumes were forecasted assuming existing land uses remain on the properties within the study area. The With Project volumes assume overlay zone land uses are constructed. Appendix D provides the 2030 forecast volumes with and without the project overlay. Figure 9 1 illustrates the Horizon Year Without Project average daily traffic volumes. Figure 9 2 illustrates the Horizon Year With Project traffic volumes on a daily basis. 9.3 Horizon Year Street Segment Operations Horizon Year Street Segment Operations Without the Mixed-Use Overlay Horizon year street segment analyses were conducted for roadways in the study area. Table 9 1 reports horizon year street segment operations without the project overlay. All of the study segments are projected to operate at LOS D or better Horizon Year Street Segment Operations With the Mixed-Use Overlay The street segment operations with the addition of the project traffic are projected to continue to operate at LOS D or better. Based on the established significance criteria, the increase in traffic as a result of the project is not substantial in relation to the existing traffic load and capacity of the street system and therefore no significant impacts would result. Therefore, mitigation measures are not necessary. LINSCOTT, LAW & GREENSPAN, engineers LLG Ref Mixed-Use Overlay Zone Project N:\1747\text\1747 Revised Report.doc

25 Segment TABLE 9 1 HORIZON YEAR STREET SEGMENT OPERATIONS LOS E Capacity a YEAR 2030 Without Project YEAR 2030 With Project Volume b V/C c LOS d Volume V/C LOS El Cajon Boulevard 70 th Street to 73 rd Street 37,000 19, B 20, B 73 rd Street to Comanche Drive 37,000 17, B 19, B Comanche Drive to Parks Avenue 37,000 17, B 17, B Parks Avenue to La Mesa Boulevard 37,000 17, B 17, B La Mesa Boulevard to Guava Avenue 37,000 15, B 17, B Guava Avenue to Baltimore Drive 37,000 22, B 20, B Baltimore Drive El Cajon Boulevard to University Avenue 37,000 30, D 33, D Spring Street I-8 On/Off Ramps to University Avenue 37,000 27, C 31, D University Avenue to La Mesa Boulevard 37,000 21, B 23, B University Avenue 70 th to Massachusetts Ave 37,000 27, C 29, D Massachusetts Ave to Yale Avenue 37,000 16, B 17, B Yale Avenue to Lowell Street 37,000 13, A 14, A Lowell Street to Parks Avenue 37,000 18, B 19, B Parks Avenue to Dale Avenue 37,000 17, B 19, B Dale Avenue to La Mesa Blvd (west) 37,000 22, B 24, B La Mesa Blvd (west) to Baltimore Drive 37,000 22, B 25, C Baltimore Drive to Spring Street 37,000 14, A 16, B Spring Street to La Mesa Blvd (east) 19,000 8, C 9, D La Mesa Boulevard El Cajon Boulevard to University Avenue (west) 16,200 9, D 9, D University Avenue (east) to Jackson Drive 37,000 18, B 18, B Jackson Drive to Grossmont Drive 37,000 15, B 16, B 70 th Street North of El Cajon Boulevard 37,000 27, C 29, D South of El Cajon Boulevard 37,000 19, B 20, B Notes: a. Capacity based on County of San Diego Roadway Standards. b. Average Daily Traffic. c. Volume to Capacity ratio. d. Level of Service. LINSCOTT, LAW & GREENSPAN, engineers LLG Ref Mixed-Use Overlay Zone Project N:\1747\text\1747 Revised Report.doc

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28 10.0 ALTERNATIVE ANALYSIS 10.1 Horizon Year Conditions The project alternatives were analyzed in this traffic study. Alternative 1 assumes 50 percent of the total project is built and is termed the reduced project alternative. Alternative 2 assumes the area is built-out as stipulated in the General Plan and is termed the no project alternative Horizon Year Traffic Volumes Reduced Project Alternative Horizon Year traffic volumes for the Reduced Project Alternative were forecasted for the study area assuming half of the overlay zone land uses are constructed and the other half are build per the City s General Plan. These forecast volumes are shown on Figure No Project Alternative Horizon Year traffic volumes for the No Project Alternative were forecasted on the area street segments assuming the study area is built-out according to the City s General Plan land uses. Figure 10 2 shows the forecast volumes Horizon Year Street Segment Operations Horizon Year Street Segment Operations with Reduced Mixed-Use Overlay Horizon year street segment analyses were conducted for roadways in the study area. Table 10 1 reports horizon year street segment operations without the reduced project overlay. All of the study segments are projected to operate at LOS D or better Horizon Year Street Segment Operations with the Current General Plan The street segment operations with the addition of the project traffic are projected to continue to operate at LOS D or better. Neither project alternative would cause an increase in traffic that is substantial in relation to the baseline conditions and therefore mitigation measures would not be necessary. LINSCOTT, LAW & GREENSPAN, engineers LLG Ref Mixed-Use Overlay Zone Project N:\1747\text\1747 Revised Report.doc

29 Segment TABLE 10 1 ALTERNATIVE HORIZON YEAR STREET SEGMENT OPERATIONS LOS E Capacity a YEAR 2030 Reduced Project YEAR 2030 No Project Volume b V/C c LOS d Volume V/C LOS El Cajon Boulevard 70 th Street to 73 rd Street 37,000 20, B 19, B 73 rd Street to Comanche Drive 37,000 18, B 18, B Comanche Drive to Parks Avenue 37,000 17, B 17, B Parks Avenue to La Mesa Boulevard 37,000 17, B 17, B La Mesa Boulevard to Guava Avenue 37,000 16, B 16, B Guava Avenue to Baltimore Drive 37,000 21, B 22, B Baltimore Drive El Cajon Boulevard to University Avenue 37,000 31, D 30, D Spring Street I-8 On/Off Ramps to University Avenue 37,000 29, C 28, C University Avenue to La Mesa Boulevard 37,000 22, B 21, B University Avenue 70 th to Massachusetts Ave 37,000 28, C 28, C Massachusetts Ave to Yale Avenue 37,000 16, B 16, B Yale Avenue to Lowell Street 37,000 13, A 13, A Lowell Street to Parks Avenue 37,000 19, B 18, B Parks Avenue to Dale Avenue 37,000 18, B 18, B Dale Avenue to La Mesa Blvd (west) 37,000 23, B 22, B La Mesa Blvd (west) to Baltimore Drive 37,000 24, B 23, B Baltimore Drive to Spring Street 37,000 15, B 14, B Spring Street to La Mesa Blvd (east) 19,000 9, C 9, C La Mesa Boulevard El Cajon Boulevard to University Avenue (west) 16,200 9, D 9, D University Avenue (east) to Jackson Drive 37,000 18, B 18, B Jackson Drive to Grossmont Drive 37,000 16, B 16, B 70 th Street North of El Cajon Boulevard 37,000 28, C 28, C South of El Cajon Boulevard 37,000 20, B 19, B Notes: a. Capacity based on County of San Diego Roadway Standards. b. Average Daily Traffic. c. Volume to Capacity ratio. d. Level of Service LINSCOTT, LAW & GREENSPAN, engineers LLG Ref Mixed-Use Overlay Zone Project N:\1747\text\1747 Revised Report.doc

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32 11.0 PEAK HOUR INTERSECTION ANALYSIS This study assesses the University Avenue / Massachusetts Avenue, El Cajon Boulevard / Baltimore Drive and La Mesa Boulevard / Jackson Drive intersections to determine the potential peak hour impacts of the proposed mixed-use overlay zone project to the road network. The existing conditions, Horizon Year without Project and Horizon Year with Project scenarios were analyzed Existing Peak Hour Intersection Levels of Service Intersection counts were collected during the AM (7:00 AM to 9:00 AM) and PM (4:00 PM to 6:00 PM) peak hours. Figure 11 1 illustrates the AM/PM peak hour existing intersection traffic volumes. Appendix E contains the peak hour intersection manual count sheets. Appendix F contains existing scenario intersection operations analysis worksheets. Table 11 1 shows that the study area intersections are calculated to currently operate at LOS D or better under existing conditions. Intersection TABLE 11 1 EXISTING INTERSECTION OPERATIONS Control Type Peak Existing Hour Delay a LOS b 1. University Avenue / Massachusetts Avenue Signal 2. El Cajon Boulevard / Baltimore Drive Signal 3. La Mesa Boulevard / Jackson Drive Signal Footnotes: a. Average delay expressed in seconds per vehicle. b. Level of Service. AM 20.7 C PM 22.0 C AM 33.1 C PM 35.8 D AM 24.9 C PM 27.0 C SIGNALIZED DELAY/LOS THRESHOLDS Delay LOS 0.0<10.0 A 10.1 to 20.0 B 20.1 to 35.0 C 35.1 to 55.0 D 55.1 to 80.0 E > 80.1 F LINSCOTT, LAW & GREENSPAN, engineers LLG Ref Mixed-Use Overlay Zone Project N:\1747\text\1747 Revised Report.doc

33 11.2 Horizon Year Peak Hour Intersection Levels of Service As mentioned previously, Year 2030 ADT s with and without the overlay were forecasted for the study area using the SANDAG Series 10 Model. Peak hour intersection turning movement volumes were estimated using a template in Microsoft Excel developed by LLG. Future peak hour traffic volumes at an intersection were determined based on the relationship between existing peak hour turning movement volumes, existing ADT volumes, and the future ADT volumes with and without the project. Figure 11 2 illustrates the Horizon Year Without Project AM/PM peak hour intersection traffic volumes. Figure 11 3 illustrates the Horizon Year With Project AM/PM peak hour intersection traffic volumes Horizon Year Peak Hour Intersection Levels of Service Without the Mixed-Use Overlay As shown on Table 11 2 under the without mixed-use project overlay, the study intersections are calculated to operate at level of service D or better. Appendix G contains horizon year without mixed-use overlay scenario intersection operations analysis worksheets Horizon Year Peak Hour Intersection Levels of Service With the Mixed-Use Overlay A shown on Table 11 2 under the with mixed-use project overlay, the study intersections are calculated to operate at a level of service D or better. The delay increases are less than significant. Appendix H contains horizon year with mixed-use overlay scenario intersection operations analysis worksheets. LINSCOTT, LAW & GREENSPAN, engineers LLG Ref Mixed-Use Overlay Zone Project N:\1747\text\1747 Revised Report.doc

34 TABLE 11 2 HORIZON YEAR INTERSECTION OPERATIONS Intersection Control Type Peak Hour Without Overlay With Overlay Delay a LOS b Delay LOS Impact Type 1. University Avenue / Massachusetts Avenue Signal AM 20.3 C 20.4 C 0.1 PM 21.4 C 21.5 C 0.1 None 2. El Cajon Boulevard / Baltimore Drive Signal AM 33.9 C 34.3 C 0.4 PM 37.4 D 38.4 D 1.0 None 3. La Mesa Boulevard / Jackson Drive Signal AM 23.8 C 24.5 C 0.7 PM 26.1 C 27.4 C 1.3 None Footnotes: a. Average delay expressed in seconds per vehicle. b. Level of Service. SIGNALIZED DELAY/LOS THRESHOLDS Delay LOS 0.0<10.0 A 10.1 to 20.0 B 20.1 to 35.0 C 35.1 to 55.0 D 55.1 to 80.0 E > 80.1 F LINSCOTT, LAW & GREENSPAN, engineers LLG Ref Mixed-Use Overlay Zone Project N:\1747\text\1747 Revised Report.doc

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38 12.0 CONSTRUCTION TRAFFIC REVIEW Construction of the project may contribute to traffic delays. Construction delays are intermittent in nature and can be characterized as work zones delay and construction traffic delay. Work Zones Work zones relate to off-site improvements activity and often require lane closures to accommodate a safe work area. Such lane closures directly result in reduced roadway or intersection capacity. Furthermore, reduced speed limits also limit the throughput of a roadway. Work zone delays are difficult to quantify without knowing the exact construction staging and work zone. Based on the overall operating conditions of the overlay zone project, it would be prudent to consider off-peak or nighttime construction schedule for all off-site construction activity that require lane closures in the peak direction. Construction Traffic Construction traffic relates to the on-site traffic generated from construction vehicles. Construction vehicles consist primarily of heavy trucks and worker vehicles. Delay incurred from this activity is of more concern since it occurs for a longer period of time and may involve a high number of vehicles. At this point in time, it is difficult to predict the expected daily construction traffic for the overlay zone project since specific projects are not part of this overlay zone project. However, construction traffic is expected to be considerably lower than the daily project trips. Based on the relatively low construction traffic, no substantial impacts are expected. It is recommended that construction traffic control plans be prepared for individual development projects that are deemed by the City to potentially impact city streets. LINSCOTT, LAW & GREENSPAN, engineers LLG Ref Mixed-Use Overlay Zone Project N:\1747\text\1747 Revised Report.doc

39 13.0 SIGNIFICANCE OF IMPACTS AND MITIGATION MEASURES Based on the established significance criteria, the increase in traffic as a result of the project is not substantial in relation to the existing traffic load and capacity of the street system and therefore no significant impacts would result. Therefore, mitigation measures are not necessary. Neither project alternative would cause an increase in traffic that is substantial in relation to the baseline conditions and therefore mitigation measures would not be necessary. LINSCOTT, LAW & GREENSPAN, engineers LLG Ref Mixed-Use Overlay Zone Project N:\1747\text\1747 Revised Report.doc

40 APPENDIX C Air Quality Technical Report

41 Air Quality Technical Report for the City of La Mesa La Mesa Mixed-Use Urban Overlay Zone Submitted To: Dudek & Associates 605 Third Street Encinitas, CA Prepared By: 1328 Kaimalino Lane San Diego, CA August 21, 2007

42 Table of Contents 1.0 Introduction Existing Conditions Existing Setting Climate and Meteorology Regulatory Setting Background Air Quality Thresholds of Significance Impacts Construction Operational Impacts Odors Global Climate Change Cumulative Impacts Conclusions and Recommendations References Air Quality Technical Report i 8/21/07 La Mesa Mixed-Use Urban Overlay Zone

43 1.0 Introduction This report presents an assessment of potential air quality impacts associated with the proposed City of La Mesa Mixed-Use Urban Overlay Zone. The evaluation addresses the potential for air emissions during construction and operations of the project, including an assessment of the potential for CO hot spots to form due to traffic associated with the proposed project. The proposed Mixed-Use Urban Overlay Zone is designed to add regulations and standards to the zoning code to implement the objectives of the General Plan. The Mixed-Use Urban Overlay Zone would guide the development of mixed-use projects on parcels zoned for residential and commercial use along University Avenue, El Cajon Boulevard, La Mesa Boulevard, and in the vicinity of the Spring Street Trolley Station at the intersection of Spring Street and Palm Avenue. New development would be subject to development standards of the new Mixed-Used Overlay Zone. As part of the proposed Mixed-Use Urban Overlay Zone, a conditional use permit would be required for all new automobile gas stations, certain other automobile uses, and drive-thru sales. Current limits on the amount of retail area on the ground floor in the residential zone would be removed. Residential uses would be permitted on the ground floor of properties in the commercial zone as long as development standards of the Mixed-Use Urban Overlay Zone are followed. The proposed Mixed-Use Urban Overlay Zone would also accommodate an increase in the maximum allowable residential dwelling units per acre in the residential zone. The allowable residential units per acre would increase from 18 to 23 dwelling units per acre to 40 dwelling units per acre, which would be consistent with General Plan policies. Additionally, the development standards in the Mixed-Use Urban Overlay Zone would increase the potential for the development of a pedestrian realm along the three corridors and near the Spring Street Trolley Station. The proposed overlay zone would employ development standards and design guidelines to facilitate the development of pedestrian areas and streetscape along the Air Quality Technical Report 1 8/21/07 La Mesa Mixed-Use Urban Overlay Zone

44 street edge creating a more walkable and attractive pedestrian environment, which would bolster the goals of the mixed-use designation in the General Plan. This Air Quality Technical Report includes an evaluation of existing conditions in the project vicinity, an assessment of potential impacts associated with project construction, and an evaluation of project operational impacts. 2.0 Existing Conditions 2.1 Existing Setting The project site is located in the City of La Mesa, located in central San Diego County, approximately 10 miles northeast of downtown San Diego and approximately 17 miles east of the Pacific Ocean. The Mixed-Use Urban Overlay Zone is located in the existing developed area along University Avenue, El Cajon Boulevard, La Mesa Boulevard, and in the vicinity of the Spring Street Trolley Station at the intersection of Spring Street and Palm Avenue. 2.2 Climate and Meteorology The project site is located in the San Diego Air Basin (SDAB). The climate of the SDAB is dominated by a semi-permanent high pressure cell located over the Pacific Ocean. This cell influences the direction of prevailing winds (westerly to northwesterly) and maintains clear skies for much of the year. Figure 2 provides a graphic representation of the prevailing winds in the project vicinity, as measured at the MCAS Miramar Meteorological Monitoring Station, the closest meteorological monitoring station to the site. The high pressure cell also creates two types of temperature inversions that may act to degrade local air quality. Subsidence inversions occur during the warmer months as descending air associated with the Pacific high pressure cell comes into contact with cool marine air. The boundary between the two layers of air creates a temperature inversion that traps pollutants. The other type of inversion, a radiation inversion, develops on winter nights when air near the ground cools by heat radiation and air aloft remains warm. The shallow inversion layer formed between these Air Quality Technical Report 2 8/21/07 La Mesa Mixed-Use Urban Overlay Zone

45 two air masses also can trap pollutants. As the pollutants become more concentrated in the atmosphere, photochemical reactions occur that produce ozone, commonly known as smog. Figure 2. Wind Rose MCAS Miramar Monitoring Station 2.3 Regulatory Setting Air quality is defined by ambient air concentrations of specific pollutants identified by the United States Environmental Protection Agency (USEPA) to be of concern with respect to health and welfare of the general public. The USEPA is responsible for enforcing the Federal Clean Air Act (CAA) of 1970 and its 1977 and 1990 Amendments. The CAA required the USEPA to establish National Ambient Air Quality Standards (NAAQS), which identify concentrations of pollutants in the ambient air below which no adverse effects on the public health and welfare are anticipated. In response, the USEPA established both primary and secondary standards for several pollutants (called criteria pollutants). Primary standards are designed to protect human health with an adequate margin of safety. Secondary standards are designed to protect property and the public welfare from air pollutants in the atmosphere. Air Quality Technical Report 3 8/21/07 La Mesa Mixed-Use Urban Overlay Zone