Key Successes

The Systemic Safety Analysis Reporting 

Program in San Diego resulted in the 

following outcomes:

Identified grouping of crashes by 

roadway user type and by location 

type.

Identified left-turn permissive phases 

as a key concern.

Identified 60 implementation 

locations for Leading Pedestrian 

Intervals (LPIs) with “No Turn” signs 

that activate when an LPI is in use.1

Prioritized roundabouts as an 

essential countermeasure to 

improve safety for all modes and 

achieve Vision Zero in the long run.2

Systemic Safety Analysis — 

San Diego, California 

VISION ZERO SUCCESS STORY — DATA

AUGUST 2020 | FHWA-SA-20-035

Background 

In 2015, the City of San Diego adopted a Vision 

Zero approach to eliminate fatalities and serious 

injuries on City streets by 2025. This approach 

included the development and implementation 

of strategies in the areas of engineering, 

enforcement, and education. A key element of 

the City’s Vision Zero program was to use data to 

select projects with the greatest safety benefit. This 

data-driven philosophy was encapsulated in the 

City’s Systemic Safety Analysis Reporting Program 

(SSARP). The Safe Transportation Research and 

Education Center at the University of California, 

Berkeley assisted with the development of SSARP, 

which included standardizing processes to 

perform crash analyses, identifying safety issues, 

and developing a list of low-cost proven safety 

countermeasures. The systemic safety approach 

evaluated the City’s entire roadway network, 

rather than individual high-crash locations, and 

identified high-risk roadway features correlated 

with common crash types.

Implementation

The SSARP grouped locations that had similar 

characteristics. The City-wide analysis of crashes 

revealed that many reported crashes occurred 

at intersections. The SSARP further revealed 

many mid-block crashes occur within proximity 

to intersections and exhibit crash characteristics 

different from other mid-block crashes further 

away from intersections. As a result, the City 

created three crash location categories: crashes 

at intersections, crashes within an intersection 

influence area (for those mid-block crashes within 2 Federal Highway Administration. (2017). “Roundabouts”. 

https://safety.fhwa.dot.gov/provencountermeasures/roundabouts/

1 Federal Highway Administration. (2017). “Leading Pedestrian 

 Intervals”. https://safety.fhwa.dot.gov/provencountermeasures/ 

 lead_ped_int/
100 feet from an intersection or the upstream 

end of a turn pocket), and crashes located 

midblock. In addition, the City conducted 

systemic safety analysis for each of the roadway 

user types of vehicles, pedestrians, and bicyclists, 

and applied the three crash categories to 

each of the user types. This resulted in a set of 

crash characteristics for each user type and by 

location category (figure 1).

Outcomes 

While the SSARP identified several safety 

concerns and associated countermeasures, it 

notably revealed a significant safety concern 

related to traffic signals with left-turn permissive 

phases which allowed for conflict between 

pedestrians and vehicles. This led to the City’s 

recommendation to revisit the warrant system 

for left-turn permissive phases to account for 

the safety of pedestrians, particularly vulnerable 

pedestrians such as the elderly, children, and 

people with disabilities. 

The SSARP also led two current efforts to retrofit 

many of the permissive left-turn locations with a 

Leading Pedestrian Interval (LPI).1 The City is also 

systemically adding activated, blank-out “No 

Turn” symbol signs that turn on when an LPI is in 

use and reduces delay when an LPI is not in use. 

Figure 1. Graphic. Excerpt from San Diego’s systemic analysis framework organized by crash characteristics, 

location category, and roadway user type.3

© 2019 City of San Diego

3 City of San Diego. (2019). Systemic Safety: The Data-Driven Path 

to Vision Zero. 
Figure 2. Graphic. Recommended intersection improvements. Lower-cost improvements using existing right-of-way.3

The City also has a long-term 

goal of outfitting intersections with pedestrian 

countdown timers and high-visibility crosswalks. 

Bundling low-cost safety improvements like LPI’s 

results in projects with high benefit-to-cost ratios 

and increases their success rate for Federal and 

State grant funds. The City plans to install LPIs 

with activated “No Turn” signs at over 60 traffic 

signals in the next couple of years. 

The SSARP also identified the highest frequency 

crash locations are at traffic signals on four-lane 

two-way streets and three-lane one-way streets 

(figure 2). 

As intersection projects in the City are less 

expensive and intrusive than roadway corridor 

projects, the City will focus on countermeasures 

at signalized intersections before corridors 

which are more complex due to timelines 

with utility projects and other constraints. 

The implementation of LPIs allows the City 

to apply an effective low-cost proven safety 

countermeasure City-wide in a short period of 

time.

In the long term, the City plans to replace many 

of its traffic signals with roundabouts (figure 3). 

On certain streets with adequate right-of-way, 

the City plans to deploy a series of roundabouts 

along with road diets.4 Roundabouts in series 

make left turns and U-turns easy and can 

repurpose right-of-way for wider sidewalks, 

bikeways, or increased parking. The City has 

already built five roundabouts in series and 

will build three more in 2020 using Federal and 

State grant funding. Roundabouts are highly 

competitive with traffic signals. Besides the 

safety benefits, they confer reduction in longterm maintenance, less energy consumption, 

and fewer carbon emissions. In addition, 

roundabouts handle greater volumes of traffic, 

work when the power is out, and boost the 

economy.

4 Federal Highway Administration. (2017). “Road Diets (Roadway 

Configuration)”. https://safety.fhwa.dot.gov/provencountermeasures/road_diets/ © 2019 City of San Diego
POINT OF CONTACT

JULIO FUENTES

SENIOR TRAFFIC ENGINEER

JFUENTES@SANDIEGO.GOV

© 2020 City of SanDiego

Figure 3. Graphic. A roundabout installation in San Diego.

Funding

The City used Caltrans’ Highway Safety Improvement 

Program (HSIP) funds for the systemic safety 

analysis. The City also used Caltrans HSIP funds 

for the installation of countermeasures identified 

in the systemic safety analysis, including LPIs, 

countdown timers, and continental crosswalks. 

The City will continue to identify specific hotspot 

locations, match them with countermeasures, and 

compete for sources of funding to implement these 

countermeasures.