HomeMy WebLinkAbout6/16/2026 Item 7d, Kacsinta and Schwartz - Staff Agenda CorrespondenceCity of San Luis Obispo, Council Memorandum
City of San Luis Obispo
Council Agenda Correspondence
DATE: June 16, 2026
FROM: Madeline Kacsinta, Assistant Director of Public Works
Prepared By: Luke Schwartz, Transportation Manager
VIA: Whitney McDonald, City Manager
SUBJECT: ITEM #7d - SOUTH STREET AND KING COURT CROSSING PROJECT
MODIFICATION, SPECIFICATION NO. 2001059
Staff received the following questions regarding the South & King Crossing Project. The
questions are below with staff’s response shown in italics:
1) Can we also reduce the speed limit on this section of South Street?
Currently, the speed limit on South Street (35 mph) is posted as low as legally
allowed; however, the traffic study used to establish the limit for this street is due
for an update within the next year and staff will explore the opportunity to lower the
limit, if allowed per the California Vehicle Code.
If a speed limit reduction is not feasible, staff can still pursue speed reduction tools
such as radar speed feedback signs. If desired by the Council, radar speed signs
could be explored as part of the current project, if project contingency funding
allows following installation of the signal/hybrid beacon, or as a separate project or
through future implementation of the Vision Zero-San Luis Obispo’s Safe Streets
Action Plan.
2) Could a pedestrian/bicycle crossing also be considered at the intersection
of South Street and Meadow Street and/or the intersection of South Street
and Beebee Street?
The Active Transportation Plan identifies potential for a future pedestrian crossing
along South Street at Meadow Street, and staff has received previous comments
from the community and members of the Active Transportation Committee (ATC)
expressing interest in a pedestrian/bicycle crossing at the intersection of South
Street and Beebee Street. Future crossings at these locations would require
separate funding, design, and analysis and would need to be prioritized through a
future Financial Plan.
Item #7d –South & King Crossing Project Modification, Specification No. 2001059 Page 2
It should be noted that based on initial review of these locations and experience
with the South & King intersection, more robust crossing treatments may be
required to achieve an appropriate level of driver compliance and crossing comfort
for pedestrians and bicyclists at these locations (i.e. pedestrian hybrid beacon,
traffic signal, intersection turn restrictions, new/modified median refuges,
streetlighting, etc.). In addition, the proximity of these intersections to adjacent
high-traffic signalized intersections at South/Higuera and South/Broad Street add
further complexity that would need to be analyzed in further detail to better
understand potential for unintended consequences with placing new traffic control
devices (i.e. vehicle queues backing up into South/Higuera or South/Broad
intersections, conflict with westbound two-to-one lane merge at South/Meadow,
etc.). Future crossings may be feasible at these locations, but further analysis is
need to confirm viability and guide future design details.
3) Does the current design limit pedestrian/bicycle crossings to the east side
of the South Street & King Street/Court intersection, or will crossings be
allowed on the west side of the intersection as well (crossing South Street)?
As previously approved, the pedestrian hybrid beacon design included crossings
on both the east and west sides of the intersection, and the proposed traffic signal
design would also provide crosswalks on both sides of the intersection as well,
consistent with the City’s Active Transportation Plan Design Guidelines (See
Policy 4.9).
4) Would the new traffic signal (replacing the pedestrian hybrid beacon) allow
for cyclists and pedestrians to “trigger” the signalized crossing phase, or
will the side street signal phases be triggered only by cars, or based on a
timed or actuated cycle?
The proposed traffic signal design would allow pedestrians and cyclists to activate
the signal to cross South Street, in addition to vehicles. The main difference with
the proposed signal is that bicyclists and motor vehicles would activate the signal
using passive video detection cameras, where with the previous pedestrian hybrid
beacon design, the bicyclists would use a curbside push button to call the
pedestrian signal phase, similar to the existing beacon at Broad/Woodbridge.
The proposed traffic signal design would use video detection cameras with the
latest in bicycle detection capabilities and staff is proposing to also include new
Bicycle Detection Indicator devices to visually convey to bicyclists that they have
been detected by the signal when waiting for a green light.
Item #7d –South & King Crossing Project Modification, Specification No. 2001059 Page 3
5) What is the expected typical delay for a pedestrian activating the push button
and then getting a pedestrian crossing signal?
Whether a pedestrian hybrid beacon or traffic signal is advanced, pedestrian delay
would generally range from 30–60 seconds depending on the timing of prior
crossings or signal phases. Both systems require a minimum clearance interval
between pedestrian activations to allow traffic to clear South Street.
The City typically sets this minimum time at 30-60 seconds between side street
crossings activations during peak times of day, with flexibility for a shorter duration
during off-peak times. The Broad/Woodbridge pedestrian hybrid beacon is
currently programmed to require 45 seconds between activations. If a pedestrian
pushes the button directly after a previous pedestrian crossing phase, the longest
they would wait to cross is 40-60 seconds. If a pedestrian pushes the button a
minute or longer after the previous pedestrian crossing or King Street/Court vehicle
green phase, the main street green light would immediately terminate to serve the
pedestrian crossing (after the yellow and all red transition).
6) Which of the intersection design options (signal or pedestrian hybrid
beacon) provides the greatest safety for pedestrians, bicyclists, and
motorists?
Safety performance is difficult to rank definitively because each option shifts
different tradeoffs. There are advantages and disadvantages in terms of
intersection crossing comfort, convenience, and conflict avoidance between the
signal and hybrid beacon design options, which vary for each road user. However,
it is staff’s opinion that the proposed traffic signal design option provides the
greatest overall benefit to all road users, improving access for vehicles turning
to/from King Street/Court, while still providing a high-quality experience for
bicyclists and pedestrians crossing South Street.
The pedestrian hybrid beacon would provide an increased benefit to pedestrian
and cyclist crossing comfort by restricting conflicting vehicle turns from King
Court/Street during the crossing phase using illuminated “NO LEFT/RIGHT TURN”
signs; however, the hybrid beacon option would not address challenges for King
Court/Street drivers navigating gaps in fast-moving traffic to turn onto South Street,
and may slightly increase these driver delays during certain times of day. The
hybrid beacon is also likely to have greater potential for driver
confusion/compliance concerns compared to a full signal.
A traffic signal would improve access for King Court/Street drivers and
pedestrian/bicycle crossings and likely provide a more intuitive design and greater
driver compliance. While a signal would permit concurrent left-right turns from King
Court/Street drivers when pedestrians are crossing South Street, the conflicting
vehicle volumes would be low and conflicts could be partially managed with signal
programming/timing strategies and warning signage. See answers to the next
question below, and the attached concept design illustration of the traffic signal for
more information on these design details.
Item #7d –South & King Crossing Project Modification, Specification No. 2001059 Page 4
7) Will the full traffic signal option include a bike signal, leading pedestrian
interval, or any other enhancements for bicycle and pedestrian safety and
convenience?
The proposed traffic signal design option is proposed to include the following
design features for bicycle and pedestrian safety and convenience:
• Accessible pedestrian signals, with audible push buttons and countdown
pedestrian signal displays
• Bicycle Detection Indicator to notify northbound/southbound King
Court/Street cyclists when they have been detected by the signal when
waiting to cross South Street.
• Leading Pedestrian Interval phases for all pedestrian crossings, which
bicyclists can also use to get a “head start” crossing the intersection per
recent changes to the California Vehicle Code.
• Electronic “NO RIGHT TURN ON RED” blank-out signs that illuminate
during the Leading Pedestrian Interval walk phase to reduce right-turning
conflicts with pedestrians during the pedestrian signal phase crossing South
Street.
• High-visibility yellow school crosswalks and new streetlighting covering all
legs of the intersection.
• “Left Turn Yield to Pedestrian” warning signs at all intersection approaches.
• Flashing yellow arrows for vehicle left turn phases from South to King Court
for added driver awareness of left-turning conflicts
8) If the pedestrian hybrid beacon were installed, would all car movement be
stopped during the bike/ped crossing phase or is there a way that left turns
for cars could be allowed exiting from King Court?
As originally designed, all left/right turns from King Court/Street would be
prohibited using a combined “NO LEFT/RIGHT TURN” illuminated sign during the
pedestrian crossing sequence for the pedestrian hybrid beacon. There are two
minor design revisions to the previous hybrid beacon design that could be explored
to allow left turns for cars exiting King Court during the crossing phase:
Item #7d –South & King Crossing Project Modification, Specification No. 2001059 Page 5
PHB Modification Option 1: The crosswalk on the west leg of the intersection could
be removed all together, which would eliminate the need to restrict left turns from
King Court during the pedestrian crossing phase.
PHB Modification Option 2: Instead of a combined “NO LEFT/RIGHT TURN”
illuminated sign, two separate “NO LEFT TURN” and “NO RIGHT TURN” signs
could be used to control King Court/Street movements. This would allow more
flexibility to activate one or both illuminated signs, depending on whether there is
a pedestrian crossing the west crosswalk, east crosswalk or both. For example,
when a pedestrian activates the east crosswalk only (no pedestrian at west
crosswalk), the “NO LEFT TURN” illuminated sign facing King Court would stay
dark, allowing King Court drivers to make left turns onto westbound South Street.
If the Council chooses to continue progress with the pedestrian hybrid beacon
project as originally planned, staff would recommend that Option 2 above
(separate “NO LEFT” and “NO RIGHT” turn signs) be incorporated into the project
designs. This option reduces potential delays for King Court drivers compared to
the original design, while retaining convenient crossings for pedestrians and
bicyclists.
If the Council is interested in exploring Option 1 above, it should be noted that this
would provide greater benefit to access for King Court vehicles making left turns,
but would provide a less intuitive/convenient crossing design for cyclists crossing
South Street in the southbound direction (towards Meadow Park), as they would
be required to travel out of direction to cross at the east leg of the intersection only.
9) For the full traffic signal option, will any of the intersection approaches
include a protected left turn phase for cars?
Based on the Traffic Signal Analysis Study prepared for this intersection
(Attachment A), protected only left turn phasing was not recommended for any of
the intersection approaches based on review of site conditions, traffic volumes,
pedestrian conflicts, and analysis of vehicle and pedestrian delays. The study
recommended permissive left turn phasing to minimize potential for congestion
and queues on South Street but suggested using flashing yellow arrows for added
driver visibility.
For the final traffic signal design (Attachment B), staff is recommending use of
“permissive+protected” left turn phasing for the South Street left turns. Using this
configuration, the left turn sequence for South Street would begin with permissive
flashing yellow arrows (drivers must yield to oncoming traffic, but may turn left
when gaps allow), and provide a lagging protected green left turn arrow only when
there are still vehicles that are queued awaiting a gap to make a left turn from
South to King. This strategy minimizes added congestion on South Street, while
still providing a dedicated left turn arrow for added capacity for left -turning drivers
during peak times of day, such as the AM school start at nearby Hawthorne
Elementary School. For context, the “permissive+protected” left turn phasing is
currently in use at the Santa Rosa/Monterey and Orcutt/Sacramento intersections
and is illustrated below.
Item #7d –South & King Crossing Project Modification, Specification No. 2001059 Page 6
10) Are there concerns that the proposed pedestrian hybrid beacon or full signal
on South Street will increase cut-through traffic along Exposition Drive?
While there is always potential that some drivers may choose to use alternate
routes to bypass perceived delays on a major street with the addition of a new
traffic signal (or hybrid beacon), staff believes that the risk of significant increases
in cut-through traffic along Exposition Drive to be low, as it is likely to take longer
to cut through these neighborhood streets to travel between South and Broad
Street than to remain on South Street.
The attached Traffic Signal Analysis Study did not explicitly analyze potential for
added cut-through traffic along Exposition in association with a potential hybrid
beacon or traffic signal at the South and King intersection; however the analysis
does present the average peak hour traffic delays and queues for drivers on
eastbound South Street, which informs staff’s assessment of cut-through potential.
Currently, it would take an eastbound driver approximately one additional minute
to travel eastbound from South Street to Broad Street on average when cutting
through Exposition Drive and Woodbridge Street rather than remaining on South
Street. A new signal or pedestrian hybrid beacon would stop eastbound traffic on
South Street for an additional 30-40 seconds maximum when activated to serve a
pedestrian crossing from King Court/Street. When a vehicle or bicycle is crossing
South Street, the signal would require less green time for King Court/Street users,
resulting in delays of 10-15 seconds on average for South Street drivers.
Further, the Higuera Complete Streets Project, slated to begin construction in the
coming months, will be adding speed humps along Exposition Drive and portions
of Woodbridge Street, which should further discourage cut-through traffic in the
neighborhood. In addition, the forthcoming corridor planning work for South Broad
Street will include detailed analysis and planning of neighborhood traffic
management within the Meadow Park Neighborhood, which could include further
consideration for traffic calming following completion of the South and King
Crossing Project, if warranted.
Item #7d –South & King Crossing Project Modification, Specification No. 2001059 Page 7
If desired by the Council, staff can collect traffic volume and speed data along
potential cut-through routes following installation of the pedestrian hybrid beacon
or signal to confirm any potential increases in neighborhood cut-through traffic. If
cut-through traffic increases are confirmed, staff would identify further traffic
calming measures, conduct outreach with the adjacent neighborhood, and return
to Council at a future date if further traffic calming measures are proposed.
ATTACHMENTS
A – Traffic Signal Analysis Study
B – Traffic Signal Design Concept
Advanced Mobility Group | 2999 Oak Rd. Suite 420, Walnut Creek, Ca. 94597 | P: 925.476.5426
www.amobility.com
Attn: Mr. Justin Wong, Transportation Planner/Engineer II
City of San Luis Obispo
919 Palm Street
San Luis Obispo, CA 93401
October 1, 2024
Subject: Traffic Engineering Study: Evaluation for Traffic Signal Installation and Preliminary
Phasing Consideration at South Street and King Court, San Luis Obispo – Deliverable No.1
Dear Luke,
This traffic engineering study is conducted by AMG in accordance with the 11th edition of the
Manual on Uniform Traffic Control Devices (MUTCD) to evaluate the need for a traffic signal at
the intersection of South Street and King Court in the City of San Luis Obispo. The study aims
to assess traffic volumes, safety concerns, and other operational characteristics to determine
whether the installation of a traffic signal is warranted at this intersection. It is also to present
preliminary phasing considerations which will be verified and justified in the next deliverable.
This study is to satisfy Task 1 in the project scope of work.
Data Sources
1. Traffic Volumes (ADT): Average Daily Traffic (ADT) data was collected over a two-day
period starting on April 19, 2022, from South Street between Higuera Street and Broad
Street. This data reflects current vehicular traffic volumes that travel through the South
Street corridor near the study intersection.
2. Turning Movement Counts: Data was collected at the study intersection by Metro
Traffic Data Inc. for the City of San Luis Obispo on May 11, 2022. The counts were
collected for vehicles, pedestrians and bicycles. The morning peak period included two
hours between seven and nine AM. The afternoon period included five hours between
one PM and six PM.
3. Collision History: Data covering collision history at the intersection of South Street and
King Court was reviewed for the years 2014-2023 to assess safety and accident patterns
at this location.
4. Site Observations: Virtual site observations were conducted to evaluate any factors
that could potentially influence engineering judgement related to the intersection
traffic control at this location. This included gaining local knowledge through
communication with City staff related to bicycle and pedestrian demographics,
pedestrian behaviors, traffic flow, and peak hour conditions.
Traffic Signal Warrant Analysis
In accordance with the MUTCD, traffic signal warrants are used to determine whether a signal
is needed at the intersection based on several criteria, including traffic volume, pedestrian
activity, and safety concerns. The following are key warrants that have been considered in this
study:
1. Warrant 1: Eight-Hour Vehicular Volume
o This warrant is met if traffic volumes exceed a certain threshold for at least eight
hours of a typical day.
o Data Review: Based on TMC data for South Street and King Street, the average
daily traffic volumes are compared against the thresholds specified in the
MUTCD, which vary based on intersection geometry and number of lanes. The
side street data were obtained from the seven hours collected with the turning
movement counts.
2. Warrant 2: Four-Hour Vehicular Volume
o This warrant applies if traffic volumes exceed thresholds for four hours of a
typical day, typically used in areas with higher traffic flow during peak times.
o Data Review: Four-Hour volumes were analyzed to assess if four-hour traffic
patterns satisfy this warrant.
3. Warrant 3: Peak Hour
o This applies if traffic volumes during the peak hour exceed thresholds that
indicate significant congestion or delay during rush hours.
o Data Review: Analysis of peak-hour traffic from the TMC data indicate whether
delays or congestion warrant signalization.
4. Warrant 4: Pedestrian Volume
o This warrant assesses whether pedestrian volumes crossing South Street would
justify the installation of a signal. Typically, a signal is recommended if
pedestrian volumes reach a certain level and there are difficulties in crossing.
o Site Observation: Pedestrian counts indicate a heavy demand during the
morning peak and moderate demand in the afternoon peak. The vehicular
volumes during this heavy pedestrian demand are also high.
5. Warrant 5: School Crossing
o While not conducted with AMG's analysis, City staff conducted an evaluation of
School Crossing Warrant and confirmed that the warrant was not satisfied, as
there were only 15 school children observed crossing during the highest crossing
hour, where the warrant requires 20 minimum.
6. Warrant 7: Crash Experience
o This warrant is triggered if there is a history of frequent collisions that could be
mitigated by the installation of a traffic signal. The criteria most suitable for this
area is summarized in Tables 4C-2 and 4C-3. There are two considerations for a
one-year and Three-year periods. The data reviewed from the City’s database
does not meet the threshold required to meet this warrant.
Intersection Characteristics and Issues
• Geometry: The intersection is a two-way stop-controlled intersection with South
Street being the major roadway and King Court being the minor approach. South
Street has one through lane lanes and one left turn lane, in each direction. King Court
operating as a single-lane approach.
• Posted Speed: The posted speed limit on South Street is 35 MPH.
• Traffic Flow: South Street experiences moderate to high vehicular flow during peak
periods, with significant east-west movements. King Court, as a minor road, sees lower
traffic volumes but often experiences long delays in making left or right turns due to
heavy traffic on South Street.
• Pedestrian Activity: Pedestrian movements are sporadic, but at morning and
afternoon peak times pedestrians experience delays in crossing South Street. The
combination of relatively high pedestrian demand (44 pedestrians and about 1381
vehicles), in all directions, during the morning peak hour, leaves limited gaps for
crossings. Most morning pedestrian traffic is school age. The proximity of the
intersection to Hawthorne Elementary School elevates the delay concerns. While the
thresholds for a pedestrian traffic signal warrant is not met, engineering judgement
suggests great benefits that could be realized with a signalized crossing.
• Bicycle Traffic: King Court is an active bicycle traffic during the morning (18) and
afternoon (11) peak periods. The intersection has been augmented with green bicycle
crossing pavement markings.
• Visibility and Line of Sight: Field observations indicate that while visibility is generally
adequate, turning movements from King Court are occasionally hindered by parked
vehicles or vegetation near the intersection.
Collision Analysis
The review of the collision history for the intersection revealed no reported injury crashes in
the past three years. No recurring patterns of broadside or rear-end collisions on South Street.
The frequency of these crashes does not meet the Crash Experience Warrant in the MUTCD,
Warrant 7. However, the time-period in review coincides with the COVID Pandemic period in
which collisions were lower than usual. A traffic signal could enhance safety and reduce the
likelihood of crashes.
Preliminary Phasing Analysis
A closer look at the turning movement counts, the product of the volumes of through traffic on
the major street times the opposite left turning traffic (+/- 39K) do not suggest the installation
of protected left turn phasing on the major Street, South Street. As a preliminary
recommendation the left turns on the major street should remain permissive only. A flashing
yellow arrow option will be considered.
The heaviest turning movement (EBLT) had 87 vehicles turning left during the morning peak.
This movement coincided with 7 pedestrians in the northerly crosswalk. We believe this
conflict is minimal and could be accommodated with permissive phasing and Leading
Pedestrian Interval (LPI).
While the volumes do not suggest splitting the side street traffic, there is no physical room to
make north and south left turns from the side street. Therefore, the side street will have to be
split.
Our goal is to provide crosswalks on all legs of the intersection. However, delay analysis will
inform this decision in the next deliverable, that is signal phasing.
Striped bicycle lanes will also be considered. The removal of the existing striped bike lane to
accommodate additional lanes might be beneficial to the overall operation. A more detailed
phasing diagram with phase assignments will be submitted in the next deliverable.
Conclusion and Recommendations
Based on the analysis of traffic volumes, safety concerns, and operational conditions at the
intersection of South Street and King Court, the following conclusions and recommendations
are made:
1. Warrants Met:
o The traffic volumes on South Street during peak hours, combined with the
observed delays for vehicles on King Court, satisfy the criteria for Warrant 3
(Peak Hour).
o No other warrants were satistified.
2. Additional Considerations:
o While pedestrian volumes do not currently meet Warrant 4 (Pedestrian
Volume), future development in the surrounding area could increase pedestrian
traffic, further justifying the installation of a signal.
o The proximity of the intersection to an elementary school and the majority of
pedestrians and bicycle traffic composed of school-aged users suggests the
installation of a more commanding traffic control at this intersection. A traffic
signal could be a potentially effective solution for enhancing safety at this
intersection.
3. Recommendation:
o It is recommended that a four-phase traffic signal be installed at the intersection
of South Street and King Court. This would improve the safety of turning
movements, reduce crash occurrences, and facilitate smoother traffic flow
during peak hours. Signalization would also enhance pedestrian safety,
particularly during busy times of the day when crossing South Street becomes
difficult.
We are glad to discuss, revisit and/or elaborate on any aspect of this study. If we don’t hear
back from your staff, we will proceed with the evaluation of the best phasing and sequence for
the signalization.
Best Regards,
Advanced Mobility Group (AMG),
Rafat Raie, TE
Principal
Cc: Luke Schwartz, Transportation Manager
Advanced Mobility Group | 2999 Oak Rd. Suite 420, Walnut Creek, Ca. 94597 | P: 925.476.5426
www.amobility.com
Attn: Mr. Justin Wong, Transportation Planner/Engineer II
City of San Luis Obispo
919 Palm Street
San Luis Obispo, CA 93401
Subject: Signal Phasing Traffic Study for the South Street and King Court Intersection – Task 1.2
Dear Justin,
We are pleased to submit this letter report detailing the results of the Signal Phasing Traffic Study for
the intersection of South Street and King Court as part of Task 1.2 in our ongoing project. The purpose of
this task is to utilize the Synchro software to perform a comprehensive Level of Service (LOS) analysis
and present signal phasing, lane configuration, pedestrians and bicycle considerations.
Geometric Layout
The first step is to validate the possibilities of concurrent and no-conflicting left turn movements from
King Court. The current layout of the intersection does not allow for two concurrent left turns from King
Court onto South Street. We investigated the possibility of shifting the centerlines on King Court.
Finding the shifts are not sufficient to create the non-conflicting movements for the Single-Unit truck
template, we explored with shortening the median island to accommodate the turns. The following
exhibits show the level of improvements needed to provide concurrent left turns out of King Court.
EXHIBIT 1.1
Passenger Car Movements with Modified Median Islands
EXHIBIT 1.2
Single-Unit Truck Movements with Modified Median Islands
In communicating with City staff, the city is willing to initiate the median island improvements and the
phasing options presented in this communication assumes the modifications of the median islands on
South Street and the striping changes on King Court.
Synchro Study Approach
Using the turning movement counts provided by the City of San Luis Obispo, we conducted a detailed
Synchro analysis. We also conducted simulations which produce a more accurate queuing results. The
objectives of the analysis were:
• Minimize traffic queues and delays: By optimizing the signal timing and phase sequencing, we
aimed to reduce overall delays and improve intersection performance.
• Determine the required lane configurations: Our study assessed the current traffic volumes to
recommend appropriate lane assignments, including through and turn lanes.
• Assess queuing lengths: We analyzed the left-turn lane queuing lengths (with the necessary
shortenings) for all approaches. The existing left turn lane will be sufficient for the average
simulation. The 95th percentile condition shows the queue length will be exceeded during a
limited number of cycles in the morning peak hour. This operation under the permissive
phasing scenario is acceptable. The alternative is to extend the storage bay which could be
costly and beyond the scope of the project.
Although the initial study did not justify the need for a protected left turn on South Street, we chose to
analyze it to investigate the effects of the protected phasing on queueing and overall delay.
The following table shows performance indicators of the comparison between permissive,
protected/permissive and protected phasing at the intersection. All these scenarios include crosswalks
on all legs of the intersection, modifications of the median islands and using LPI for all pedestrian
phases. In addition, striped bicycle lanes at the signal approaches on King will have to be removed to
make room for the turning vehicles. The bicycle striping could be converted to Sharrows.
Table 1.1
Signal Performance Indicators Comparison
Synchro Simulation
Option 1:
Permissive
Phasing
Option 2:
Protected
Permissive
Phasing
Option 3:
Protected
Phasing
Actuated Cycle Length 55 50 60 55 60 55
Time of Day AM PM AM PM AM PM
Intersection Vehicular Delay
(s) 14.3 12.2 15.4 13.3 17.4 15.7
Overall LOS B B B B B B
Pedestrian Delay (s) 25 35 30 40 30 40
Approach
Vehicular Delay (s)
EB Left 21.6 19.0 17.8 16.7 33.6 32.6
EB Thru 14.1 10.1 14.1 10.2 13.5 13.3
WB Left 16.4 20.0 14.4 17.9 36.5 33.8
WB Thru 10.6 10.4 13.6 12.5 16.4 13.0
NB 19.4 9.5 7.5 14.3 16.0 17.3
SB 4.9 9.2 15.8 11.4 6.4 11.9
50th Percentile
Queue Length (ft)
EB Left* 49 25 46 31 59 34
EB Thru 165 137 165 149 173 172
WB Left* 3 15 2 15 3 18
WB Thru 107 144 133 162 140 169
NB 16 14 22 16 21 18
SB 27 17 26 15 28 17
95th Percentile
Queue Length (ft)
EB Left* 98 60 90 77 102 79
EB Thru 323 281 308 287 332 360
WB Left* 21 44 16 48 17 49
WB Thru 187 297 245 338 255 323
NB 41 34 51 39 50 46
SB 52 42 57 41 56 40
*Storage Capacity: EBLT is 73 Ft and WBLT is 56 ft.
Key Findings and Recommendations
• Intersection Level of Service (LOS): Based on the analysis, the intersection operates at LOS A
with Option Number 1. This option seems to be the most reasonable as it produces the least
delays and yields shorter queues, in general.
• Other options are displayed for the city to evaluate and consider.
• The permissive phase could be designed with a Flashing Yellow Arrow (FYA).
• Lane Configuration Recommendations: To minimize delays and improve traffic flow, we
recommend the following configurations:
o Southbound Approach (King Court): One shared through and right lane and one
dedicated left turn lane. Parking will be prohibited on both sides of the street.
o Northbound Approach (King Court): One shared through and right lane and one
dedicated left turn lane. Parking will be prohibited on both sides of the street.
o Eastbound and Westbound Approaches (South Street): Maintain a through lane and a
left turn lane for each approach and maintain the Class II bicycle lane.
• Bicycle striping on King Court and crossing South Street should be eliminated.
• Left-Turn Queuing Lengths: The analysis suggests that the existing left-turn lane on South
Street can accommodate the projected queuing lengths without major modifications, except
for minor lane striping improvements.
• The intersection should have four crosswalks. The color of the crosswalk should be yellow as
the intersection is within the allowable distance from an elementary school. Added visibility
features such as crosshatching the crosswalk will be considered.
Proposed Improvements
Based on our findings, the following improvements are recommended at the intersection:
• The median islands on South Street should be shortened by about 15 on the west side and 10
feet on the east end,
• Signal timing optimization to reduce delays and improve traffic flow efficiency, especially
during peak hours.
• Minor geometric improvements to the lane striping to better accommodate the turning
movements and queuing demands.
We are confident that the recommended improvements will significantly enhance traffic flow and safety
at the intersection of South Street and King Court. We’ll continue to work with your Civil consultant to
ensure consistency of design elements for the most safe and efficient operation of the traffic signal.
If you have any questions or would like to discuss any aspect of this study further, please feel free to
contact me at 925-525-1113 or via email at rafat@amobility.com.
Best Regards,
Advanced Mobility Group (AMG),
Rafat Raie, TE
Principal
Advanced Mobility Group
rafat@amobility.com
925-525-1113
Cc: Luke Schwartz, Transportation Manager