Mission Gorge/ Navajo Ethernet Communications Upgrades – Basis of Design The City of Coronado
Traffic Signal Assessment Report
Executive Summary
August 2024
Prepared for:
City of Coronado
Public Services and Engineering
1825 Strand Way
Coronado, CA 92118
Prepared by:
STC Traffic
5973 Avenida Encinas, Suite 218
Carlsbad, CA 92008
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Executive Summary, Traffic Signal Systems Assessment Report City of Coronado 1
1 Introduction
The City of Coronado initiated an assessment of traffic signals on SR-75 within the City in late 2022. The project was conducted in two distinct parts: (1) an assessment of traffic signals maintained and operated by the City and (2) an operational assessment of traffic signals within the “Village” portion of the City that are maintained and operated by Caltrans. The comprehensive assessment of traffic signals maintained and operated by the City includes equipment, operations, and systems while the assessment of traffic signals maintained and operated by Caltrans in the Village focuses on operations.
Traffic signals play a critical role in providing safe and efficient mobility on Coronado’s roadways and it’s important to periodically evaluate conditions to determine the state of repair and operation. The traffic signal assessment project purpose is to review conditions, identify deficiencies, and provide recommendations for improvement. The assessment of traffic signals maintained and operated by the City is more extensive to provide the City an asset inventory and information that will feed into current and future City maintenance and capital improvement plans. The project is documented in two separate reports: City of Coronado Traffic Signal Assessment Report (November 2023) and City of Coronado Caltrans Traffic Signal Operation Assessment Report (February 2024). The reports accompany this Executive Summary.
Traffic signal operations are the core focus of the two assessments and were the impetus for the project.
Coronado residents experience the City’s traffic signals daily and have voiced operational issues to City staff and leadership. Although maintenance and operations of the traffic signals in Coronado are split between two different agencies they are part of one contiguous corridor through the community, State Route 75 (SR-75), Orange Avenue on the north and Silver Strand Blvd on the south.
This Executive Summary focusses on corridor wide traffic signal operations with a high-level overview of the extensive information provided in the two reports distilled into a brief of the key findings and recommendations.
2 Corridor Overview - Orange Avenue and Silver Strand Blvd A map of the project corridor is shown in Figure 2-1 on the following page with the traffic signals numbered one to thirteen. Table 2-1 below provides a corresponding list of the intersection names. The City of Coronado maintains and operates seven traffic signals, six along the Silver Strand Blvd segment and one on Orange Avenue. Caltrans District 11 maintains and operates six intersections along the Orange Avenue segment.
Table 2-1 Traffic Signal Intersection List
Number Intersection Maintained By
1 Orange Avenue & First Street City
2 Orange Avenue & 3rd Street Caltrans
3 Orange Avenue & 4th Street Caltrans
4 Orange Avenue & 6th Street Caltrans
5 Orange Avenue & 8th Street Caltrans
6 Orange Avenue & 10th Street Caltrans
7 Orange Avenue & R.H. Dana/Adella Caltrans
8 Orange Avenue & Pomona Avenue City
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Traffic Signal Systems Assessment Report
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Number Intersection Maintained By
9 Orange Avenue/ Silver Strand Blvd & Avenida Del Sol City 10 Silver Strand Blvd & Avenida de Las Arenas City
11 Silver Strand Blvd & Rendova Road City
12 Silver Strand Blvd & Tarawa Road City
13 Silver Strand Blvd & Tulagi Road City
Figure 2-1 Corridor Map
3 Traffic Signal Operation Findings
Traffic signal operations were both observed on the street and analyzed with traffic analysis software. The findings are summarized by intersection and/ or peak period on the figures and tables on the following pages.
Table 3-1 Traffic Analysis Results
Num Intersection AM MID PM
LOS Delay LOS Delay LOS Delay
1 Orange Avenue & 1
st Street A 8.5 B 10.3 A 9.9
2 Orange Avenue & 3rd Street C 29.4 C 25.7 B 19.1
3 Orange Avenue & 4th Street B 17.9 E 77.3 F 89.5
4 Orange Avenue & 6th Street B 17.8 C 26.4 C 30.2
5 Orange Avenue & 8th Street C 21.6 C 31.1 C 28.5
6 Orange Avenue & 10th Street C 22.1 D 41.1 D 42.0
7 Orange Avenue & R.H. Dana/Adella F 218.1 E 55.8 C 27.7 8 Orange Avenue & Pomona Avenue A 1.0 A 0.7 A 0.8
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Traffic Signal Systems Assessment Report
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Num Intersection AM MID PM
LOS Delay LOS Delay LOS Delay
9 Orange Ave/ Silver Strand & Avenida Del Sol A 7.5 A 9.1 A 9.1 10 Silver Strand Blvd & Avenida De La Arenas B 13.9 B 16.0 B 16.1 11 Silver Strand Blvd & Rendova Road E 66.2 A 3.0 A 2.6 12 Silver Strand Blvd & Tarawa Road F 85.7 E 64.2 C 32.3 13 Silver Strand Blvd & Tulagi Road A 9.6 A 5.2 B 15.8
LOS = Level-of-Service, Delay = seconds per vehicle
• Poor LOS at 4
th Street reflect high volumes, both vehicles and pedestrians, and primary bridge and Naval Base access. Northbound and southbound delays create spillbacks on Orange Avenue between the 3
rd and 4th Street intersections.
• Poor LOS at R.H. Dana/Adella reflect high volumes, both vehicles and pedestrians, and primary hotel and beach access. Lack of coordination with adjacent intersections at Pomona Avenue and 10th Street increases the delay.
• Poor LOS at Rendova Road and Tarawa Road reflect high volumes associated with primary and secondary Naval Base access. Pedestrian and bicyclist volumes increase in the middle of the day.
The operational analysis validates conditions observed on the street. Spillover and delay between intersections on the main approaches cause delay across the overall corridor. Delay on left turn movements cause pockets to spill over into through lanes.
Bus stops on Orange Avenue block vehicles in the number two lane and causes backup to upstream intersections. Parking along the corridor also causes frequent obstruction of the number two lane by delivery trucks, parking enforcement officers, and waiting vehicles. The parking and bus maneuvers effectively reduce the roadway capacity to one lane in each direction.
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Traffic Signal Systems Assessment Report
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Figure 3-1 AM Observations and Issues
Figure 3-2 Midday Observations and Issues
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Figure 3-3 PM Observations and Issues
4 Recommendations
Signal systems and operations on the corridor are outdated and observed to be in a poor state of repair.
The following table provides a high-level summary of deficiencies and recommendations.
1. Decommission the legacy SCOOT adaptive system. The SCOOT system is proprietary and outdated; its user interface is difficult to use, programming is not intuitive and requires a high degree of familiarity with the software, and technical support can be a challenge as it is typically provided by non-local personnel. Implementation of a new open source platform adaptive system, ideally able to be coordinated Caltrans-operated signals along the corridor, should be considered.
2. Update coordination plans corridor wide. A review of the Caltrans signal timing sheets shows current coordination timing was implemented approximately 10 years ago. New coordination timing plans based on current traffic conditions will provide reliable and uniform operation across Caltrans and City corridor segments. This will reduce southbound bottlenecks at 10th Street, R.H.
Dana/Adella, and Pomona Avenue. The yellow yield operation at 3rd Street and 4th Street on Orange Avenue should be removed.
3. Replace legacy 170 controllers. These are end-of-life and no longer manufactured or supported.
These also have limited capability compared to modern ATC controllers. This applies to all Caltrans signals and Orange Avenue/ 1
st Street.
4. Implement a uniform and modern corridor wide traffic management system. The systems and operations on the corridor are disjointed between the City and Caltrans. Uniform systems will Attachment 4
Traffic Signal Systems Assessment Report
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lead to uniform operations. Traffic flow and proximity of signals requires system uniformity for efficient operation. A modern system will provide functionality including the ability to monitor system health and performance which promotes reliability and active system management.
5. Implement a modern communication system. The existing communication system across the corridor is outdated, low bandwidth, and incapable of supporting modern traffic management system data demand. Replace it with a new high-speed and reliable communication system.
6. Review ped crossings, phasing, detection, and geometry. a. 1
st Street, 8th Street, and R.H. Dana/Adella: Separate single phases to dual. Flashing yellow arrow operation rather than permissive green balls for improved pedestrian safety. b. Consolidate operation at Avenida Del Sol and Pomona Avenue to a single cabinet and controller due to proximity.
c. Avenida De La Arenas: Remove third ring and operate pedestrian movement independently. Remove northbound pedestrian movement per safety report. d. Repair pedestrian detection at Pomona Avenue and Avenida Del Sol and this will immediately reduce delay.
e. Check CA-MUTCD timing compliance. Make existing timing split adjustments for immediate delay reduction.
f. Implement bike detection and zones to discourage bicyclists from pushing the pedestrian button.
g. Review bus stops and on-street parking operations.
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