HomeMy WebLinkAbout2025-08-04; Traffic Safety and Mobility Commission; 02; Citywide Speed Limit EvaluationMeeting Date: Aug. 4, 2025
To: Traffic Safety & Mobility Commission
Staff Contact: Miriam Jim, Senior Engineer
miriam.jim@carlsbadca.gov, 442-339-5796
John Kim, City Traffic Engineer
john.kim@carlsbadca.gov, 442-339-2757
Subject: Citywide Speed Limit Evaluation
District All
Recommended Action
Receive a report on a citywide speed limit evaluation focusing on the changes incurred with the
passage of Assembly Bill 43.
Background
The California State Legislature establishes authority for the posting of speed limits through the
California Vehicle Code, or CVC. The CVC describes speed limit authority primarily for
enforcement purposes. The California Manual on Uniform Traffic Control Devices, or CA
MUTCD, establishes the standard procedure for setting legally defensible speed limits in
compliance with the CVC.
On Oct. 8, 2021, Assembly Bill 43, or AB 43, titled “Traffic Safety,” was passed by the State of
California legislature, and subsequently approved by the Governor and filed with the Secretary
of State. AB 43 modified provisions of the CVC which provide local authorities with more
flexibility in setting speed limits, particularly in areas with high collision frequencies and high
pedestrian and bicycle traffic.
In March 2023, the CA MUTCD was revised to incorporate the provisions of AB 43 with specific
procedures and definitions pertaining to the setting of speed limits in California.
In June 2023, the city began working with a consultant on a citywide speed limit evaluation to
review how recent AB 43 related changes to the CVC and CA MUTCD affect posted speed limits
on city streets.
Discussion
TRAFFIC SAFETY & MOBILITY COMMISSION
Aug. 4, 2025 Item #2 Page 1 of 23
How Speed Limits Are Determined
The procedure for setting speed limits as described in the CA MUTCD requires the speed limit to
be established near the 85th percentile speed of free-flowing traffic. The 85th percentile speed,
also known as the “critical speed,” is the speed at or below which 85% of the traffic is moving.
Speed limits based on prevailing speeds form the basis of speed law in the US and in California.
As with most laws, speed limits depend on the voluntary compliance of the greater majority of
motorists. Setting speed limits too low can lead to widespread noncompliance and reduced
respect for the law. However, if there are safety concerns not immediately apparent to drivers,
the speed limit may be reduced by up to 5 miles per hour, or mph, below the 85th percentile
speed.
Speed limits on the roadways are required to be established on the basis of an Engineering and
Traffic Survey, or E&TS. An E&TS consists of engineering measurements of the 85th percentile
speed, a review of collision history and a review of roadway conditions. E&TS should be
conducted at least once every five, seven, or 14 years, in compliance with CVC Section 40802,
to ensure that speed limits reflect any significant changes in the roadway since the last review.
CVC Section 22352 sets two prima facie speed limits in California, 15 mph and 25 mph, which
means these speed limits apply by default, even if there are no signs posted. These limits cover
six specific classes of location. No E&TS or speed limit signs are required for these situations.
These six classes of location are as follows:
•Uncontrolled railroad crossings (15 mph)
•Blind, uncontrolled intersections (15 mph)
•Alleyways (15 mph)
•Locations that meet residential district requirements (25 mph)
•School zones (25 mph)
•Areas immediately around senior centers (25 mph)
AB 43: New Options for Setting Speed Limits
Outside of the prima facie speed limits described above, AB 43 has modified provisions of the
CVC, giving local authorities greater flexibility in setting speed limits, particularly in areas with
high collision frequencies and high pedestrian and bicycle traffic. Below is a brief summary of
the changes to the CVC and CA MUTCD per AB 43 in setting speed limits outside of the prima
facie situations.
•Additional 5-mph reduction: In addition to the initial 5-mph reduction allowed for
roadway conditions not readily apparent to drivers, an additional 5-mph reduction may
be applied by one or more of the following conditions:
o Streets designated as “Safety Corridors” as defined in the CA MUTCD. A safety
corridor is a roadway segment within an overall roadway network where the
highest number of serious injury and fatality collisions occurs. Up to 20% of the
overall roadway network of the city can be designated as “Safety Corridors.”
o Streets that are adjacent to land or facilities that generate high levels of bicycle
or pedestrian activity as defined by the CA MUTCD.
Aug. 4, 2025 Item #2 Page 2 of 23
• Business Activity District: Local authorities may, by ordinance, determine and declare a
25 or 20 mph prima facie speed limit on roadways contiguous to a business activity
district as defined in the CA MUTCD.
Citywide Speed Limit Evaluation
As part of the citywide speed limit evaluation, a speed zone evaluation was conducted in
accordance with changes initiated by AB 43. The study analyzed a total of 144 roadway
segments in the city to identify opportunities for speed limit reductions per AB 43. This
included prioritization of “Safety Corridors” within the overall city roadway network and streets
that are adjacent to land or facility that generates high levels of bicycles or pedestrians as
defined in the CA MUTCD. As part of the evaluation, five-year collision data, between 2018 and
2022, were reviewed and weighted, in consideration of factors like collision severity, involved
mode and age group, proximity to school, to prioritize “Safety Corridors” within the overall city
roadway network.
A memorandum documenting the analysis methodology and results of the speed limit
reduction evaluation is included in Exhibit 1.
Conclusion
Vehicle speeds on a roadway are affected by various factors, primarily the roadway
characteristics and to some extent surrounding environment, adjacent land uses, traffic control
devices like traffic signals, signage and striping, and speed enforcement on the roadway. As
such, the most effective way to reduce speeds would be through a combination of strategies
using roadway design and engineering solutions, traffic calming measures, traffic control
devices related to speed management, and education and enforcement efforts.
While lowering posted speed limits may have a short-term effect on driver behavior, it is not an
effective long-term strategy for managing speeds unless paired with physical or operational
changes to the roadway. Signage alone does little to influence driver behavior over time. For
this reason, a broad, citywide implementation of speed limit reductions under AB 43 is not
recommended.
However, the results of this speed limit evaluation can be considered as an additional tool in
evaluating speed limits on a case-by-case basis. Staff will consider the new allowances in setting
speed limits as defined in the CVC and CA MUTCD in coordination with the Police Department
on an as-needed basis. Any recommended changes to the existing posted speed limit for a
speed zone will be presented to the Traffic Safety & Mobility Commission for review and
recommendation, and subsequently to the City Council for adoption of an ordinance for the
proposed speed limit.
Public Notification
This item was noticed in keeping with the Ralph M. Brown Act and it was available for public
viewing and review at least 72 hours before the scheduled meeting date.
Exhibits
1. Citywide Speed Limit Evaluation Memorandum
Aug. 4, 2025 Item #2 Page 3 of 23
555 W Beech Street | Suite 302 | San Diego, CA 92101 | (619) 234-3190 www.fehrandpeers.com
Memorandum
Date: July 29, 2025
To: Miriam Jim and Lindy Pham; City of Carlsbad
From: Erin Ferguson, Kendra Rowley, and Emily Turner; Fehr & Peers
Subject: Carlsbad Citywide Speed Limit Evaluation Methodology
SD23-0488
Introduction
Speed is one of the main contributing factors to the severity of collisions. Higher travel speeds on
public streets not only increase the likelihood of being involved in a collision, they also increase
the severity of injuries sustained by all road users involved in a collision, as shown in Figure 1.
Figure 1: Relationship between Vehicle Speed, Collisions, and Fatalities1
For this reason, many cities across the country are adopting the Safe System Approach,2 which
includes Safe Speeds as one of its five core elements. The Safe System Approach has also been
adopted by the U.S. Department of Transportation (USDOT) and the California Department of
1 https://scag.ca.gov/sites/main/files/file-attachments/cal-guidance-hin-090221.pdf?1633549750 2 https://www.transportation.gov/NRSS/SafeSystem
Exhibit 1
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Transportation (Caltrans). The Safe System Approach is based, in part, on the principle that,
because the severity of a collision is correlated to the force of impact, safe speeds help reduce the
severity of injuries, if a collision should occur.
As part of the City of Carlsbad’s commitment to roadway safety and reducing fatalities and
injuries on public roadways, the City has completed a citywide speed limit evaluation consistent
with the recent Assembly Bill (AB) 43 legislation and the 2014 California Manual on Uniform
Traffic Control Devices (CA MUTCD), Revision 8. To determine which corridors could be prioritized
for speed limit reduction allowances per AB 43, the following criteria were considered:
- 85th Percentile Speed (eligible for 5 mph reduction if nearest 5 mph increment requires
rounding down)
- Safety Corridor Designation (eligible for 5 mph reduction)
- Proximity to Bicyclist/Pedestrian Generators (eligible for 5 mph reduction)
- Business Activity District Designation (eligible for 25 or 20 mph prima facie speed limit)
While reducing posted speed limits is a proven mechanism to reduce operating speeds, most
studies suggest that effective speed management relies on other factors as well.3 Section 2B.13 of
the CA MUTCD states that the most effective way to reduce vehicular speeds is through a
combination of speed management strategies including, but not limited to, roadway design and
engineering solutions, traffic calming techniques and measures, public education, enforcement
efforts, and traffic control devices. Therefore, the City should seek to comprehensively improve
safety outcomes by complementing speed limit reductions with other safety countermeasures,
particularly engineering improvements. Operating speed and driver behavior are intrinsically
linked to roadway design, making engineering improvements such as curb extensions and raised
crosswalks highly effective at lowering speeds, and therefore, injury and fatality rates.
The following section describes the methodology used to conduct the City of Carlsbad’s speed
limit evaluation.
Speed Limit Evaluation Criteria
A total of 136 roadway segments were evaluated for potential speed limit reductions per AB 43.
These segments reflect the City’s existing speed zones and have posted speed limits that were
established based on Engineering and Traffic Surveys (E&TS), as described in the CA MUTCD. Each
segment was evaluated based on the following criteria: 85th percentile speed, Safety Corridor
designation, proximity to bicyclist/pedestrian generators, and Business Activity District
designation.
3 https://escholarship.org/uc/item/5hg5m6sm
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There are eight (8) additional roadway segments in the Village and Barrio area that do not
currently have speed limits established. These segments were solely evaluated for Business
Activity District eligibility.
85th Percentile Speed
The E&TS speed limit setting process requires local agencies to first conduct an E&TS to collect
vehicular speeds using a calibrated radar or other electronic speed measuring device. Based on
the cumulative measured speed data, the 85th percentile speed (i.e., the speed at which 85% of
drivers are traveling at or below) is then determined and rounded according to the following CA
MUTCD guidelines:
1. If the nearest 5 mph increment of the 85th percentile speed requires rounding up, the
posted speed limit can be rounded down to the nearest 5 mph increment below the 85th
percentile speed, if no further reduction is used.4
2. If the nearest 5 mph increment of the 85th percentile speed requires rounding down, the
roadway qualifies for an additional 5 mph speed reduction (i.e., the posted speed limit
can be reduced by 5 mph from the nearest 5 mph increment of the 85th percentile
speed).5
Sample 85th percentile speeds and the application of the speed limit setting guidelines described
above for local agency roadways and private roadways subject to the California Vehicle Code
(CVC) are shown in Table 1. E&TS data from 2012-20226 served as the basis for the City’s speed
limit evaluation.
4 Further reductions that preclude this rounding do not include the Safety Corridor or proximity to bicyclist/pedestrian generators designations as described in the following sections. See MUTCD Section 2B.13, paragraph 12l and 12m. 5 If the speed limit to be posted has had this 5 mph reduction applied, the corresponding E&TS must document in writing the conditions and justification for the lower speed limit. These conditions should be in compliance with CVC Section 627 and 22358.5 and approved by a registered Civil or Traffic Engineer. 6 Per the CA MUTCD, an existing E&TS that was performed before January 1, 2022 is not required to be updated until due for reevaluation five (5), seven (7), or 14 years from the date of the survey.
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Table 1: Examples Showing Applicability of Rounding 85th Percentile Speed and Additional
Speed Reduction
Source: CA MUTCD 2014 Edition, Revision 8, Chapter 2B, Table 2B-104(CA)
Safety Corridor Designation
Safety Corridor designation is one of two new options to reduce the speed limit by 5 mph.7 The
other option is proximity to bicyclist/pedestrian generators, which will be discussed in the
following section. The CA MUTCD defines a Safety Corridor as “a roadway segment within an
overall roadway network where the highest number of serious injury and fatality crashes occur.”
Per the CA MUTCD, Safety Corridors should not constitute more than 20% of a local jurisdiction’s
overall roadway network.
As part of this evaluation, the City developed a data-driven network of Safety Corridors in
accordance with the definition described in the CA MUTCD. Attachment A indicates which study
segments fall on the Safety Corridor Network and are eligible for this reduction. A map of the
City’s Safety Corridor Network and the methodology used to develop this network can be found
in Attachments B and C, respectively.
Proximity to Bicyclist/Pedestrian Generators
Proximity to bicyclist/pedestrian generators is the second of two new options (the first one being
Safety Corridor designation, as described above) to reduce the speed limit by 5 mph. Per the CA
MUTCD, local authorities can apply a 5 mph speed limit reduction if the roadway is adjacent to
any land or facility that generates high concentrations of bicyclists or pedestrians, especially those
from vulnerable groups such as children, seniors, persons with disabilities, and the unhoused.
To meet this criterion, the roadway segment must have one (1) or more bicyclist/pedestrian
generators present within a distance of 1,320 feet. A list of qualifying bicyclist/pedestrian
7 The two options for lowering the speed limit by 5 mph, Safety Corridor designation and proximity to bicyclist/pedestrian generators, are presented in tandem in the CA MUTCD, meaning that whether a roadway satisfies one or both criteria, it is eligible for a reduction of no more than 5 mph.
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generators, which includes the presence of bicycle and pedestrian infrastructure, is provided in
Table 2.8 If the roadway segment is longer than 1,320 feet, a minimum of one (1) generator must
be present for every 1,320 feet.
For all but one study segment, this criterion was satisfied through the City’s existing sidewalk
infrastructure alone (i.e., every quarter mile sub-segment had sidewalk present within a quarter
mile).
Table 2: Requirements to Determine Land or Facility that Generates High Concentrations
of Bicyclists or Pedestrians
Source: CA MUTCD 2014 Edition, Revision 8, Chapter 2B, Table 2B-106(CA)
8 Per the CA MUTCD, crash data that demonstrates a roadway segment is within the top 20% of the local jurisdiction’s pedestrian and/or bicyclist fatalities or serious injuries over a 3-5 year period can be used in lieu of one of the generators listed in Table 2. If the roadway segment is longer than 1320 feet, a minimum of one (1) location within the top 20% of pedestrian and/or bicyclist KSI collisions must be present for every 1320 feet. This metric is most suitable for jurisdictions with dense pedestrian and bicycle activity (and therefore a high concentration of collisions). This was not used for Carlsbad given that pedestrian and bicycle activity is spread out over a large geography.
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Business Activity District Designation
Per the CA MUTCD, local authorities can declare, by ordinance or resolution, a 25 or 20 mph
prima facie speed limit on a roadway contiguous to a Business Activity District if the roadway has
four (4) or fewer travel lanes and meets one of the following conditions:
1. Maximum posted speed limit of 30 mph immediately prior to and after the Business
Activity District, if establishing a 25 mph prima facie speed limit.
2. Maximum posted speed limit of 25 mph immediately prior to and after the Business
Activity District, if establishing a 20 mph prima facie speed limit.
The CA MUTCD defines a Business Activity District as “the portion of a highway and the property
contiguous thereto that includes central or neighborhood downtowns, urban villages, or zoning
designations that prioritize commercial land uses at the downtown or neighborhood scale.” To
qualify as a Business Activity District, an area must meet at least three (3) of the following four (4)
requirements:
1. No less than 50% of the contiguous property fronting the highway consists of retail or
dining commercial uses, including outdoor dining, that open directly onto sidewalks
adjacent to the highway.
2. Parking, including parallel, diagonal, or perpendicular spaces, located alongside the
highway.
3. Traffic control signals or stop signs regulating traffic flow on the highway, located at
intervals of no more than 600 feet.
4. Marked crosswalks not controlled by a traffic control device.
Table 3 shows the roadway segments eligible for Business Activity District designation.
Table 3: Eligible Business Activity District Segments
Street From To Allowable Prima Facie Speed Limit
Carlsbad Boulevard Oak Avenue Grand Avenue 25 mph
Grand Avenue State Street Jefferson Street 20 mph
State Street Oak Avenue Laguna Drive 20 mph
Roosevelt Street Oak Avenue Grand Avenue 20 mph
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Attachment A – Safety Corridor
Evaluation Results
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1 Alga Road El Camino Real to Melrose Drive 50
2 Alicante Road Gateway Road to Poinsettia Lane 30
3 Alicante Road Poinsettia Lane to Alga Road 40
4 Alicante Road Alga Road to Corte de la Vista 40 X
5 Ambrosia Lane Poinsettia Lane to Conosa Way 40
6 Ambrosia Lane Conosa Way to Aviara Parkway 35
7 Anillo Way Levante Street to Madrilena Way 35
8 Armada Drive Palomar Airport Road to LEGOLAND Drive 40 X
9 Aston Avenue College Boulevard to Rutherford Road 40
10 Avenida de Anita Marron Road to Carlsbad Village Drive 25
11 Avenida Encinas Cannon Road to Palomar Airport Road 35
12 Avenida Encinas Palomar Airport Road to 0.67 Mi. s/o Palomar Airport Road 40 X
13 Avenida Encinas 0.67 Mi. s/o Palomar Airport Road to a Point 0.35 Mi. n/o 30 X
14 Avenida Encinas 0.35 Mi. n/o Macadamia Drive to Poinsettia Lane 35 X
15 Avenida Encinas Poinsettia Lane to Carlsbad Boulevard 35
16 Aviara Parkway Palomar Airport Road to Poinsettia Lane 45
17 Aviara Parkway Poinsettia Lane to El Camino Real 40
18 Batiquitos Drive Camino de las Ondas to Poinsettia Lane 30 X
19 Batiquitos Drive Poinsettia Lane to Golden Star Lane 40
20 Batiquitos Drive Golden Star Lane to Aviara Parkway 40
21 Black Rail Road Poinsettia Lane to Aviara Parkway 40 X
22 Cadencia Street Del Rey Avenue to 0.15 Mile North of Piragua Street 35
23 Calle Acervo Camino de los Coches to Calle San Blas 30
24 Calle Acervo Calle San Blas to Rancho Santa Fe Road 30
25 Calle Barcelona South City Limits to El Camino Real 40 X
26 Calle Barcelona El Camino Real to Rancho Santa Fe Road 45
27 Calle Barcelona Rancho Santa Fe Road to Calle Acervo 30 X
28 Calle Timiteo La Costa Avenue to Camino de los Coches 30
29 Camino de las Ondas Paseo del Norte to Aviara Parkway 35
30 Camino de los Coches Rancho Santa Fe Road to La Costa Avenue 40
31 Camino Hills Drive Faraday Avenue to Browning Road 35
32 Camino Junipero Rancho Santa Fe Road to Paseo Encino 45
33 Camino Vida Roble Palomar Oaks Way (N) to El Camino Real 40
34 Cannon Road Carlsbad Boulevard to Paseo del Norte 35 X
35 Cannon Road Paseo del Norte to El Camino Real 50 X
36 Cannon Road El Camino Real to College Boulevard 50 X
37 Car Country Drive Cannon Road to Paseo del Norte 35
38 Carlsbad Boulevard North City Limits to State Street 35 X
39 Carlsbad Boulevard State Street to Walnut Avenue 30 X
40 Carlsbad Boulevard Walnut Avenue to Tamarack Avenue 30 X
41 Carlsbad Boulevard Tamarack Avenue to 1,400 feet s/o Manzano Drive 35 X
42 Carlsbad Boulevard 1,400 Feet s/o Manzano Drive to Island Way (Northbound Lanes 50
43 Carlsbad Boulevard 1,400 Feet s/o Manzano Drive to Island Way (Southbound Lanes 50 X
44 Carlsbad Boulevard Island Way to South City Limits 50 X
45 Carlsbad Village Drive Ocean Street to Pio Pico Drive 25 X
46 Carlsbad Village Drive Pio Pico Drive to Highland Drive 35 X
47 Carlsbad Village Drive Highland Drive to El Camino Real 40 X
48 Carlsbad Village Drive El Camino Real to College Boulevard 40
Safety Corridor
(eligible for 5
MPH reduction)
ID Street Limits
Posted
Speed
Limit
Aug. 4, 2025 Item #2 Page 11 of 23
49 Cassia Road El Camino Real to Poinsettia Lane 35 X
50 Chatham Road Carlsbad Village Drive to Tamarack Avenue 25
51 Chestnut Avenue Pio Pico Drive to El Camino Real 30 X
52 Chestnut Avenue El Camino Real to Sierra Morena Avenue 30
53 College Boulevard North City Limit to Cannon Road 45 X
54 College Boulevard Palomar Airport Road to El Camino Real 50 X
55 Corte de la Vista Alicante Road/El Fuerte Street intersection to Easterly Terminus 35
56 (The) Crossings Drive Northerly Terminus to Palomar Airport Road 40
57 Dove Lane Moorhen Place to El Camino Real 35
58 Eagle Drive Lionshead Avenue to Palomar Airport Road 35
59 El Camino Real North City Limits to Hosp Way 35 X
60 El Camino Real Hosp Way to Kelly Drive 55 X
61 El Camino Real Kelly Drive to Faraday Avenue 55 X
62 El Camino Real Faraday Avenue to Alga Road/Aviara Parkway 55 X
63 El Camino Real Alga Road/Aviara Parkway to South City Limit 55 X
64 El Fuerte Street Faraday Avenue to Palomar Airport Road 45 X
65 El Fuerte Street Palomar Airport Road to Alga Road 45
66 El Fuerte Street Alga Road to Corte de la Vista 35
67 Estrella de Mar Road Alga Road to 675 feet north of Beryl Way 30
68 Faraday Avenue Cannon Road to College Boulevard 40
69 Faraday Avenue College Boulevard to Orion Street 40 X
70 Faraday Avenue Orion Street to East City Limit 50
71 Gabbiano Lane Batiquitos Drive to Southerly Terminus 30
72 Glasgow Drive Carlsbad Village Drive to Edinburgh Drive 30
73 Gateway Road El Camino Real to El Fuerte Street 35
74 Grand Avenue Ocean Street to Easterly Terminus 25 X
75 Hidden Valley Road Palomar Airport Road to Camino de las Ondas 35
76 Hillside Drive Highland Drive to Neblina Drive 35
77 Hosp Way Monroe Street to El Camino Real 30
78 Hummingbird Road Batiquitos Drive to Rock Dove Street 30
79 Impala Drive Palmer Way to Orion Street 35
80 Jackspar Drive El Camino Real to Camino Hills Drive 35
81 Jefferson Street Marron Road to Grand Avenue 35
82 Kestrel Drive Aviara Parkway to Batiquitos Drive 35
83 La Costa Avenue 100 Feet West of Interstate Highway 5 to El Camino Real 55
84 La Costa Avenue El Camino Real to 1,000 Feet East of El Camino Real 35 X
85 La Costa Avenue 1,000 Feet East of El Camino Real to Rancho Santa Fe Road 40
86 La Costa Avenue Rancho Santa Fe Road to Camino de los Coches 45 X
87 La Costa Avenue Camino de los Coches to Circulo Sequoia 35 X
88 Laguna Drive State Street to Jefferson Street 30 X
89 Las Flores Drive Jefferson Street to Highland Drive 30
90 Levante Street El Camino Real to Escenico Terrace 35
91 Lionshead Avenue Melrose Drive to East City Limit 50
92 Loker Avenue East El Fuerte Street to Palomar Airport Road 35
93 Loker Avenue West Palomar Airport Road to El Fuerte Street 35
94 Marron Road North City Limits Near Highway 78 to El Camino Real 40 X
95 Marron Road El Camino Real to Easterly Terminus 35
96 Melrose Drive North City Limit to Palomar Airport Road 55 X
97 Melrose Drive Palomar Airport Road to Rancho Santa Fe Road 55 X
98 Monroe Street Marron Road to Carlsbad Village Drive 45 X
99 Olivenhain Road El Camino Real to City Limits 50 X
100 Palmer Way Cougar Drive to Faraday Avenue 35 X
101 Palomar Airport Road Carlsbad Boulevard to Paseo del Norte 35 X
102 Palomar Airport Road Paseo del Norte to Armada Drive 45 X
103 Palomar Airport Road Armada Drive to El Camino Real 55 X
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104 Palomar Airport Road El Camino Real to Easterly City Limit 55 X
105 Palomar Oaks Way Northerly Terminus to Palomar Airport Road 35
106 Park Drive Hillside Drive to Valencia Avenue 35
107 Paseo Acampo Paseo Hermosa to Rancho Bravado 25
108 Paseo Avellano Segovia Way to Calle Barcelona 30
109 Paseo Candelero Alicante Road to Alga Road 30
110 Paseo del Norte Cannon Road to Car Country Drive 35 X
111 Paseo del Norte Car Country Drive to Palomar Airport Road 40 X
112 Paseo del Norte Palomar Airport Road to Poinsettia Lane 40
113 Pio Pico Drive Carlsbad Village Drive to Tamarack Avenue 35
114 Poinsettia Lane Carlsbad Boulevard to Paseo del Norte/Lowder Lane 35 X
115 Poinsettia Lane Paseo del Norte/Lowder Lane to Aviara Parkway 50 X
116 Poinsettia Lane Aviara Parkway to Cassia Road 50 X
117 Poinsettia Lane Cassia Road to El Camino Real 45 X
118 Poinsettia Lane El Camino Real to Melrose Drive 50 X
119 Pontiac Drive Victoria Avenue to Tamarack Avenue 35
120 Rancho Bravado Melrose Drive to Paseo Monona 35
121 Rancho Santa Fe Road North City Limits to La Costa Avenue 55
122 Rancho Santa Fe Road La Costa Avenue to Olivenhain Road/Camino Alvaro 50 X
123 Rancho Santa Fe Road Olivenhain Road to South City Limits 45
124 Rutherford Road Faraday Avenue to Priestly Drive 35
125 State Street Carlsbad Boulevard to Oak Avenue 25 X
126 Tamarack Avenue Carlsbad Boulevard to Interstate Highway 5 30 X
127 Tamarack Avenue Interstate Highway 5 to Skyline Road 30 X
128 Tamarack Avenue Skyline Road to El Camino Real 35 X
129 Tamarack Avenue El Camino Real to Carlsbad Village Drive 45
130 Tamarack Avenue Carlsbad Village Drive to Harwich Drive 35
131 Tamarack Avenue Harwich Drive to College Boulevard 35
132 Tamarack Avenue College Boulevard (N) to College Boulevard (S)30 X
133 Town Garden Road El Camino Real to Alicante Road 40
134 Windrose Circle Avenida Encinas to Navigator Circle(S)/Capstan Drive 35
135 Xana Way Alga Road to Unicornio Street 25
136 Yarrow Drive Palomar Airport Road to Camino Vida Roble 40
N/A Jefferson St Grand to Pine N/A X
N/A Madison St Laguna to Magnolia N/A X
N/A Harding St Grand to Magnolia N/A X
N/A Roosevelt St Laguna to Magnolia N/A X
N/A Oak Ave Ocean to Harding N/A
N/A Chestnut Ave Pio Pico to Carlsbad Blvd N/A
N/A Laguna Dr Jefferson to Eastern End N/A
N/A Pine Ave Ocean to Harding N/A
XX Village streets
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Attachment B – Safety Corridor
Network
Aug. 4, 2025 Item #2 Page 14 of 23
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Aug. 4, 2025 Item #2 Page 15 of 23
Attachment C – Safety Corridor
Methodology
Aug. 4, 2025 Item #2 Page 16 of 23
C-1
Safety Corridor Guidance Considerations
A Safety Corridor is defined as a roadway segment within an overall roadway network where the
highest number of fatal and serious injury (KSI) crashes occur. Per the CA MUTCD, Safety
Corridors should represent a prioritized subset of a local jurisdiction’s overall roadway network
and therefore cannot exceed 20% of the local jurisdiction’s roadways. A Safety Corridor Network
should be consistent with the following requirements:
• Developed using at least one of the crash weighting factors listed in Table C1
• Identifies specific locations with high crash occurrences
• Identifies corridor-level segments with a pattern of crash reoccurrence
• Able to be stratified by mode
Further considerations that informed this methodology were based on best practices from Vision
Zero cities and the Recommendations for California Statewide Guidance on High Injury Networks
report1 from the California Strategic Highway Safety Plan Bicycle and Pedestrian Challenge Area
Teams.
For more information on Safety Corridors, refer to CVC Section 22358.7(a)(1) of the CA MUTCD.2
1 https://scag.ca.gov/sites/default/files/old/file-attachments/cal-guidance-hin-090221.pdf?1633549750= 2 https://dot.ca.gov/-/media/dot-media/programs/safety-programs/documents/ca-mutcd/rev8/camutcd2014-rev8-all.pdf
Aug. 4, 2025 Item #2 Page 17 of 23
C-2
Table C1: Safety Corridor Factors
Source: CA MUTCD 2014 Edition, Revision 8, Chapter 2B, Table 2B-105(CA)
Safety Corridor Data Sources and Definitions
Collision Data
The Safety Corridor Network was developed using the most recent five (5) years of collision data
(2018-2022) from SafeTREC’s Transportation Injury Mapping System (TIMS).3 This dataset only
includes injury collisions (i.e., Property Damage Only collisions were excluded) on City-maintained,
at-grade public roadways. Collisions on state highway facilities (e.g., Interstate 5) were excluded
from the dataset, except those located at the intersection of a state highway ramp and a City-
maintained roadway. To confirm consistency across datasets, the TIMS dataset was carefully
reviewed and cross-checked against Crossroads Software’s Traffic Collision Database.
Disadvantaged Communities
According to CalEnviroScreen 4.0, an environmental health screening/mapping tool developed by
the California Environmental Protection Agency’s (CalEPA) Office of Environmental Health Hazard
3 The Transportation Injury Mapping System (TIMS) was developed by SafeTREC to provide quick, easy, and free access to California crash data, the Statewide Integrated Traffic Records System (SWITRS), that has been geo-coded by SafeTREC to make it easy to map crashes.
Aug. 4, 2025 Item #2 Page 18 of 23
C-3
Assessment (OEHHA), there are no CalEPA-defined disadvantaged communities in the City of
Carlsbad. Therefore, disadvantaged community status was not used as a crash weighting factor.
Vulnerable Populations
Census tract-level demographic data from the most recent 5-year American Community Survey
(ACS) estimates (2017-2021) was used to identify vulnerable populations in the city. According to
the Safety Corridor Factors, vulnerable populations are defined as seniors age 65 and older and
youth under age 15.
School Proximity
The California School Campus Database (CSCD) was used to identify public schools and
colleges/universities in the city. Private schools were identified using the Schools dataset from
SANDAG’s Open Data Portal.
Safety Corridor Network Methodology
The methodology for developing the City of Carlsbad’s Safety Corridor Network, informed by the
CA MUTCD Safety Corridor Factors, uses a proactive approach that involves incorporating
collision factors in addition to known location-based risk factors to prioritize Safety Corridors,
rather than relying solely on collision history. The methodology also incorporates the Highway
Safety Manual (HSM)-recommended Sliding Window method4 that is referenced in the CA
MUTCD. The Sliding Window method is a network screening method that uses overlapping
roadway segments, or “windows,” to smooth any errors in crash location reporting. For the City of
Carlsbad, the City’s roadway network was converted into overlapping, 0.25-mile segments. Each
segment was then scored based on the severity and density of collisions within 50 feet of it, as
well as several other contextual factors. The scoring factors that were applied to all roadway
segments to develop the City’s Safety Corridor Network are summarized in the following sections.
Collision Factors
The methodology used involves assigning a weight to certain types of collisions. For this analysis,
each collision was assessed based on the following factors: collision severity, mode, and victim
age.
Collision Severity
The scoring factor with the greatest influence on Safety Corridor prioritization is collision severity.
Collision severity weights were derived from 2022 California Local Road Safety Manual (LRSM)
crash costs by crash severity level. This method is similar to the Highway Safety Manual (HSM)
4 AASHTO, Highway Safety Manual, 1st Edition (2010), Chapter 4 Network Screening, p. 4-15.
Aug. 4, 2025 Item #2 Page 19 of 23
C-4
Equivalent Property Damage Only (EPDO) weighting method,5 except it uses the “Complaint of
Pain” severity level as its baseline since Property Damage Only (PDO) collisions are not included.
Cost assumptions included in the 2022 Caltrans LRSM are based on costs from the HSM First
Edition, with costs adjusted to 2022 dollars. The HSM uses “comprehensive” or “societal” crash
costs to associate crash costs with each crash severity level. Comprehensive costs include both
economic costs and monetized pain and suffering costs. Economic costs are monetary costs
associated with emergency services deployment, medical services, congestion impacts from a
crash, productivity loss due to victim injury, insurance and legal costs, and property damage costs.
Monetized pain and suffering costs are an assumption of the costs associated with lost quality of
life (or Quality-Adjusted Life Years), accounting for reductions in life expectancy and quality of life
changes as a result of a crash.
Table C2 lists the estimated crash costs and collision weights for each severity level. This
methodology uses all injury collisions in the Safety Corridor Network development process (as
opposed to KSI only).
Table C2: Collision Weights by Severity
Severity Crash Cost Collision Weight**
Fatal and Severe Injury (KSI) $2,363,667* 26
Evident Injury – Other Visible $159,900 2
Possible Injury – Complaint of Pain $90,900 1
*The fatal and severe injury (KSI) collision cost is an average of the location type costs (signalized intersections, non-signalized intersections, roadway). **Rounded to the nearest whole number.
Vulnerable Victim Factors
Two (2) additional collision factors, mode and vulnerable population by age, were also considered
to account for discrepancies in collision reporting, specifically for vulnerable road users. As
discussed in the Recommendations for California Statewide Guidance on High Injury Networks
report,6 because police assessment of injury severity is based on an officer’s primarily visual
assessment of a victim at the scene of a collision, victim injuries are commonly underreported. To
offset some of those reporting discrepancies and prioritize vulnerable road users, collisions
involving a bicyclist or pedestrian and/or a CA MUTCD-defined senior or youth (based on TIMS
victim data) were assigned a weight of 3 for a maximum potential vulnerable victim score of 6.
5 The equivalent property damage only (EPDO) method assigns weighting factors related to the societal costs of fatal, injury, and property damage only crashes to crashes by severity to develop an equivalent property damage only score that considers frequency and severity of crashes. https://safety.fhwa.dot.gov/local_rural/training/fhwasa14072/sec4.cfm 6 https://scag.ca.gov/sites/main/files/file-attachments/cal-guidance-hin-090221.pdf?1633549750
Aug. 4, 2025 Item #2 Page 20 of 23
C-5
The goal of this additional weight was to elevate the score for a collision reported as non-severe
(evident injury or possible injury) if the collision involved a vulnerable road user.
Once a collision score had been assigned to each collision, each collision was then associated with
a roadway segment(s) using a 50-foot buffer. Collisions within 50 feet of two roadway segments
(e.g., at an intersection) were assigned to each segment and scored twice, once for each segment.
As shown in Table C3, the cumulative collision score for a single collision (taking into account
collision severity and vulnerable victims involved) can range from 1 to 32.
Location-Based Risk Factors
In addition to the collision factors described above, two (2) location-based risk factors, school
proximity and vulnerable population by age, were evaluated for each roadway segment. The
predictive, contextual nature of these factors can help to identify locations with high risk, rather
than just locations with a history of KSI collisions. Segments within a quarter mile of a school or
within a Top Youth/Senior Census Tract7 were assigned a weight of 3 for a maximum potential
risk score of 6.
Overall Score: Safety Index
Cumulative scores for both collision and location-based risk factors were then summed together
to get an overall Safety Index for each roadway segment. Based on the scoring for each variable
shown in Table C3, the largest emphasis is on KSI collisions, with the other collision and location
factors adding a nuance to the scoring that provides minor distinctions between the final scores
for each segment. This nuance can help to manage the number of corridors that meet the cutoff
for the final Safety Corridor Network without exceeding the CA MUTCD maximum threshold of
20% of the City’s roadway network.
7 Consistent with CalEPA’s methodology for designating disadvantaged communities, a Top Youth/Senior Census Tract was defined as a census tract that ranks in the top 25% of the City’s overall population of CA MUTCD-defined seniors and youth. The CA MUTCD defines seniors as individuals age 65 and older and youth as individuals under the age of 15.
Aug. 4, 2025 Item #2 Page 21 of 23
C-6
Table C3: Safety Corridor Network Scoring
Variable Value Score
Collision Factors
Collision Severity (mutually exclusive) – applied to collision
Fatal and Severe Injury (KSI) 0 or 1 26
Evident Injury – Other Visible 0 or 1 2
Possible Injury – Complaint of Pain 0 or 1 1
Vulnerable Victim Factors (not mutually exclusive) – applied to collision
Mode: involves bicyclist or pedestrian 0 or 1 3
Victim Age: age 65+ or under 15 (based on victim data from TIMS) 0 or 1 3
Risk Factors
Location-Based Factors (not mutually exclusive) – applied to segment
Vulnerable Population: age 65+ or under 15 (based on census tract-level data from ACS) 0 or 1 3
School Proximity (within 0.25 miles) 0 or 1 3
Building the Network
Once a Safety Index score had been assigned to each roadway segment, the highest scoring
segments were identified according to CA MUTCD guidance, which states that Safety Corridors
should not constitute more than 20% of the overall roadway network and should account for at
least 25% of KSI collisions. The draft Safety Corridor Network for the City of Carlsbad constitutes
17.9% of the overall roadway network and accounts for 95% of KSI collisions.
Smoothing the Network
Finally, a “smoothed” network was created by filling gaps and correcting anomalies in the
resulting Safety Corridor Network. If a non-Safety Corridor link less than 0.5 miles (a value that
can be adjusted, if necessary) existed between two (2) Safety Corridor links, especially along a
roadway with a consistent cross-section and other contextual factors, it was added to the final
Safety Corridor Network. Some segments were removed from the Safety Corridor Network at the
City’s discretion to prioritize arterial roadways with the highest incidence of KSI collisions.
Aug. 4, 2025 Item #2 Page 22 of 23
C-7
Benefits of a Safety Corridor Network
In addition to using a Safety Corridor Network to identify locations where a lower speed limit is
appropriate, the designation can be used to inform other decisions and functions at the City level,
such as:
• Priorities for active transportation improvements
• Priorities for grant funding (e.g., Active Transportation Program, Safe Streets and Roads
for All, RAISE Discretionary Grants, Highway Safety Improvement Program, and many
regional grant programs prioritize funding to locations identified as a Safety Corridor or
part of a high injury network)
• Types of improvements to be integrated into maintenance activities on those roadways
(e.g., installing low-cost countermeasures like retro-reflective backplates at existing
signals)
• Types of frontage improvements required as part of development review and approval
• Types of enhancements incorporated into capital improvement projects
Safety Corridor designations can be revisited and updated approximately every five (5) years;
ideally on a similar timeline as a comprehensive safety action plan (CSAP) or local roadway safety
plan (LRSP) is updated.
Aug. 4, 2025 Item #2 Page 23 of 23
Carlsbad Citywide Speed
Limit Evaluation
Miriam Jim, Senior Engineer
John Kim, City Traffic Engineer
Aug. 4, 2025
RECOMMENDED ACTION
•Receive a report on a citywide speed limit
evaluation focusing on changes incurred with
the passage of Assembly Bill 43
ITEM 2: SPEED LIMIT EVALUATION
2
3
OUTLINE
•Background
•How Speed Limits are Established
•Speed Limit Evaluation Results
•Conclusion
•Next Steps
ITEM 2: SPEED LIMIT EVALUATION
BACKGROUND
ITEM 2: SPEED LIMIT EVALUATION
•California Vehicle Code (CVC) – Establishes
laws governing speed limit setting
•California Manual on Uniform Traffic Control
Devices (CA MUTCD) – provides guidance on
speed limit setting in compliance with the
CVC and standard on traffic control devices
BACKGROUND, CONT’D
ITEM 2: SPEED LIMIT EVALUATION
•In October 2021, Assembly Bill 43, titled “Traffic Safety” was
passed by the State Legislature and subsequently approved
by the Governor.
•AB 43 modified provisions of the CVC, which allow local
authorities with more flexibility in setting speed limits,
particularly in areas with high collision frequency and high
pedestrian and bicycle traffic.
5
6
BACKGROUND, CONT’D
ITEM 2: SPEED LIMIT EVALUATION
•In March 2023, CA MUTCD was revised to incorporate
provisions of AB 43 with specific procedures and definitions
pertaining to the setting of speed limits in California.
•City conducted a citywide speed limit evaluation to review
how changes to the CVC and CA MUTCD per AB 43 affect
posted speed limits on city streets.
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7
HOW SPEED LIMITS ARE ESTABLISHED
ITEM 2: SPEED LIMIT EVALUATION
•CVC sets two prima facie speed limits, 15 and 25 mph for six
specific types of roadways – for example, uncontrolled railroad
crossings (15 mph), residential district & school zones (25 mph)
•Speed limits on ALL OTHER roadways are established
based on an Engineering & Traffic Survey (E&TS):
•Engineering measurement of 85th percentile speed
– at or below which 85% of the traffic is moving
•Collision history
•Roadway conditions
8
HOW SPEED LIMITS ARE ESTABLISHED
ITEM 2: SPEED LIMIT EVALUATION
•Current procedures require speed limits to be established near the
85th percentile speed of free-flow traffic
•Allow for a reduction of up to 5 mph from the 85th percentile speed
if there are factors not immediately apparent to drivers (i.e. collision
history)
•Speed limits based on prevailing speed form the basis of speed law
in the US and in CA
•Setting speed limits too low can result in widespread noncompliance
9
ASSEMBLY BILL 43
ITEM 2: SPEED LIMIT EVALUATION
•Allows an additional 5 mph reduction in establishing speed limits by
one or more of the following:
•Streets designated as “Safety Corridors” as defined in the CAMUTCD.
Up to 20% of the overall roadway network of the city can be designated
as “Safety Corridors”
•Streets adjacent to land or facilities that generate high concentrations of
bicyclists or pedestrians, as defined in the CA MUTCD
•Allows local authorities, by ordinance, declare a 25 or 20 mph prima
facie speed limit on roadways contiguous to “Business Activity
Districts”
10
ITEM 2: SPEED LIMIT EVALUATION
Safety
Corridor
Designation
Eligible for 5 mph reduction
Proximity to
Bike/ Ped
Generators
Business Activity
District
Designation
Eligible for 25 or 20 mph
prima facie speed limit
SPEED LIMIT EVALUATION CRITERIA
11
ITEM 2: SPEED LIMIT EVALUATION
•A roadway segment within the overall roadway network where the
highest number of serious injury and fatality crashes occur
•With consideration of factors:
•Crash severity
•Mode: Ped/bike related crashes, vehicle or other
•Disadvantaged Community
•Vulnerable Populations: Seniors (age 65 and older) and Youth (under
age 15) based on the American Community Survey
•School proximity (within 0.25 miles)
•Evaluation utilized five-year collision data, 2018 and 2022 to
prioritize “Safety Corridors” within the city roadway network
“SAFETY CORRIDORS”
Proposed
Safety
Corridor
Network
12
13
ITEM 2: SPEED LIMIT EVALUATION
PED/BIKE INFRASTRUCTURE: Sidewalks,
Crosswalks, Bikeways, Micromobility Devices
TRANSIT: Transit Stops, Transit-Oriented
Developments / Transit Priority Areas
LAND USE: Employment Centers, Retail, Senior
Centers, Health/Medical, Facilities, Parks
DEMOGRAPHICS: Vulnerable Groups (seniors, youth, unhoused, etc.),
MPO or Locally-Defined Disadvantaged Community Status, Students
BIKE/PED GENERATORS
14
STRATEGIES
•Lowering speed limits and lowering vehicle speeds are not the
same thing
•Enforcement resources must be considered when considering
speed limit changes
•Signage alone has limited effect on driver behavior
•Changing roadway characteristics is an important tool in term
of changing driver behavior
•Best way to reduce speeds is through a combination of
strategies – roadway design changes combined with traffic
control devices (signage), education and enforcement efforts
ITEM 2: SPEED LIMIT EVALUATION
15
PROPOSED ACTION
•Consider new allowances in speed limit setting in
coordination with Police Dept on as-needed basis
•Any recommended changes to posted speed
limits will be presented to TS&MC and
subsequently City Council for review and
adoption of ordinance
ITEM 2: SPEED LIMIT EVALUATION
Questions?
21
BUSINESS ACTIVITY DISTRICT
Roadway Requirements (must meet all)
Business Activity District Requirements (must meet 3 of 4)
•Maximum of 4 traffic lanes
•Maximum posted 30 mph prima facie speed limit immediately prior to and after Business Activity District, if establishing 25 mph speed limit
•Maximum posted 25 mph prima facie speed limit immediately prior to and after Business Activity District, if establishing 20 mph speed limit
•No less than 50% of contiguous property fronting roadway consists of retail or dining commercial uses that open directly onto sidewalks adjacent to roadway
•Parking, including parallel, diagonal, or perpendicular spaces, located alongside roadway
•Traffic control signals or stop signs regulating traffic flow on roadway, located at intervals of no more than 600 feet
•Marked crosswalks not controlled by traffic control device
ITEM 2: SPEED LIMIT EVALUATION