Thousand Oaks staff outline how intersections qualify for new traffic signals; one intersection prioritized for construction

Engineering staff told the Traffic and Transportation Advisory Commission on June 25 that intersection signal installations in Thousand Oaks follow the California Manual on Uniform Traffic Control Devices (CAMUTCD) warrants, and the city uses a points system to prioritize locations for new traffic signals.

Bradley Ackert, engineering associate, said the city maintains 136 traffic signals. He told commissioners that a new signal typically requires about $50,000 for design and roughly $500,000 for construction, and that annual maintenance averages about $3,000 per signal.

Ackert explained the city focuses on CAMUTCD’s Warrant 1, an eight-hour vehicle-volume measure split into conditions a, b and a combination of both. He described how the city also reviews the last 36 months of collision reports to count “correctable” collisions — mainly approach-turn and right-angle crashes — and awards points for meeting warrant conditions, collision history and engineering considerations such as sight distance. He said additional points are added when observed volumes exceed 200% of the minimum warrant volumes.

The city applied the process to the intersection cited in Ackert’s example, Erb’s Road and Sunset Hills Boulevard, and found it met condition a but not condition b or the combination warrant. Ackert said the point system produced a new priority list in which 12 intersections met a warrant. "Avenida De Los Arbulas at Avenida De Los Plantas" is at the top of the list, he said; construction of that signal has been included in the recently adopted capital improvement budget.

Ackert summarized next steps: preliminary design and public outreach, then final design and construction. He said preliminary design and outreach typically take three to six months and that supply lead times for signal poles can be up to nine months. Staff estimated construction could start in 2026 if design and procurement proceed on schedule, with typical completion for large signal projects around 2027.

Commissioners asked how the city accounts for non‑volume factors. Ackert and Public Works Director Nader Haidari said collision types, sight distance and engineering judgment are built into the other-considerations portion of the points rubric. Commissioner Guerra described the Avenida De Los Arbulas/Avenida De Los Plantas location as “dangerous” and asked about timing; Ackert reiterated the budget inclusion and the anticipated multi-year timeline.

The presentation was informational only; commissioners were not asked to vote or make a recommendation on the signal priority list at the meeting. Ackert said the city is actively monitoring 23 intersections, 12 of which currently meet a warrant, and plans to re-count volumes and update the list by 2027.