To: PUBLIC WORKS, SAFETY, AND SUSTAINABILITY COMMISSION
From: DEPARTMENT OF PUBLIC WORKS
TITLE
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DISCUSSION OF POTENTIAL TRAFFIC CALMING MEASURES AT OPAL & IRENA INTERSECTION
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EXECUTIVE SUMMARY
In early March 2026, the City received a traffic calming request for the closely spaced intersections of Torrance Boulevard at S Irena Avenue (Torrance/Irena) and S Irena Avenue at Opal Street (Irena/Opal), as well as speeding, non-resident cut-through, and safety concerns along Opal Street between S Irena Avenue and Prospect Avenue. Engineers from the City visited the locations and analyzed various solutions. At this time, staff is proposing measures to slow down drivers at Irena/Opal and wishes to gather feedback from the public and the Public Works, Safety, and Sustainability Commission (PWSSC) prior to implementation. Notice of this agenda item was mailed to residents within 150 feet of Irena/Opal and residents along Opal St between Irena Ave and Juanita Ave.
BACKGROUND
City staff visited the site and evaluated the existing conditions of the area (see aerial view in Attachment 1). Torrance and Irena intersect as a conventional side-street stop-controlled intersection. Immediately to the south, Opal terminates at Irena, with a private property driveway acting as the fourth leg of the intersection. At the Irena/Opal intersection, only the northbound Irena and westbound Opal approaches are stop-controlled, while the eastbound driveway approach is de facto stop-controlled. The southbound Irena approach is uncontrolled, which means that of the three public street approaches at Irena/Opal, two approaches stop while the remaining southbound approach has highest right-of-way. This configuration is highly unusual, which is why modern street design tends to avoid closely spaced intersections. Furthermore, this configuration asks drivers on northbound Irena to stop twice within less than 100 feet, first at Opal and again at Torrance. This can result in poor compliance at either or both stop signs on Irena. As remarked by the resident(s) and observed by City staff, drivers turning onto Irena from Torrance, a higher speed environment, are able to avoid significantly slowing down before performing a subsequent left-turn onto Opal (a lower speed street) by driving over existing yellow centerlines and/or driving in the opposing lane on Opal. Attachment 1 also illustrates the shallow turn paths that drivers could take to reach Opal from Torrance without slowing down to desired and appropriate speeds. The presence of the northbound stop on Irena at Opal further encourages drivers coming southbound on Irena from Torrance to make left-turns onto Opal without yielding or paying much attention to the other vehicular approaches or crosswalks.
ANALYSIS
City staff is presenting two possible solutions with the goals of slowing down driver turns and removing an unusual and unexpected traffic control scenario.
Northbound Irena at Opal - Stop Removal
City staff highly recommends removing stop controls for the northbound Irena approach at Opal. This would revert the intersection back to a conventional T-intersection, where drivers typically expect the terminating street to stop and give right-of-way/priority to through-running streets. Northbound drivers already need to stop at Torrance Boulevard, less than 100 feet to the north. An existing cross gutter (dip) on Irena 150 feet south of the Irena/Opal intersection serves as a de facto speed bump. This dip and the subsequent stop at Torrance should help maintain northbound operating speeds at similar levels even if the stop at Opal is removed. If recommended by the PWSSC, staff will forward the stop removal to the City Council for final approval.
Irena/Opal Centerline Hardening
Centerline hardening is a traffic calming technique that adds vertical/physical elements to a street’s centerline (or apparent extension of the centerline) to enforce sharper and slower turns. A variety of bumps and delineators can be installed to deter drivers who attempt to take turns from Torrance directly onto Opal at high speeds. The presence of these traffic calming treatments will help drivers adjust from a 35 mph environment to a 10-25 mph environment. Slower speeds also provide more time for drivers to yield to pedestrians and reduces the area of exposure for crosswalks. Centerline hardening has been deployed with much success in cities all around the country. Possible options for centerline hardening at this intersection are listed below and examples are shown in Attachment 2:
• Taller yellow delineators reinforced on a base rail along the centerline of Irena between Torrance and Opal. While delineators are flexible, this treatment is highly visible and effective at enforcing drivers to stay on their side of the street. As an alternative, 8” diameter yellow raised pavement markers (domes) could be used here, but would not be as visible from drivers making left-turns from Torrance.
• 8” diameter yellow raised pavement markers (domes) and a striped median nose at the eastern leg of Opal/Irena to reinforce the Opal centerline. This will discourage drivers from driving the wrong way on Opal. While not as visible as taller delineators, driving over these domes would result in a severe speed bump type disruption for drivers. The City has seen good compliance with these domes. Staff recommends these lower domes for aesthetic and maintenance reasons.
• A low-profile speed bump in the middle of Irena/Opal to encourage drivers to take a slower sharper turn onto Opal. The speed bump is positioned to avoid contact by most drivers and vehicle types. Even if traversed, it would significantly disrupt only those drivers attempting to turn at higher speeds. This feature is optional and staff would like the PWSSC’s feedback before installing this feature.
If the centerline hardening is recommended by the PWSSC, staff will proceed with installation, as this measure would not need City Council approval. Funding is available for this treatment in the City’s Traffic Calming budget.
COORDINATION
Coordination of this report took place within the Public Works Department.
ATTACHMENTS
• Existing Conditions
• Proposed Traffic Calming at Irena/Opal