Traffic and Parking Commission backs cooperative agreement with Irvine to settle shared traffic‑mitigation costs; recommends city council approval

The Lake Forest Traffic and Parking Commission voted unanimously on Oct. 6, 2025 to recommend that the City Council approve a cooperative agreement with the City of Irvine to finalize fair‑share cost obligations for several shared intersections identified in the Lake Forest Transportation Mitigation Program (LFTMP).

City staff told the commission that the LFTMP is a developer fee‑based program adopted in 2008 that identifies intersection and signal improvements needed to mitigate traffic impacts from development. Tran Tran, traffic engineering manager, said city staff periodically updates the program to reflect current cost estimates and to confirm which improvements remain necessary. "The purpose of the co op agreement is simply to finalize the fair share cost obligations at these shared intersections," Tran said.

Staff identified four intersections that involve overlapping obligations between Lake Forest and Irvine. Tran said three of those intersections are already under construction and that Lake Forest has begun paying construction costs. The staff report and presentation state that Irvine will contribute about $301,000 toward the program and noted one Lake Forest obligation of roughly $676,000 for improvements at Alton Parkway and Irvine Boulevard (also described in the presentation as adding a triple‑left turn pocket and related lane shifts and right‑of‑way work).

Tran told commissioners the $676,000 figure is the city’s estimated share for the Alton/Irvine intersection and that the project is budgeted in the current fiscal year. He also said that construction costs have increased since the last five‑year update — staff cited an approximate 20–30% rise in construction costs and design expenses in recent years — and that the cooperative agreement insulates Lake Forest from later cost increases for the specific improvements once Lake Forest pays its agreed share.

Commissioners asked how the cost estimates were developed and whether change orders or future cost escalations would require additional city approvals. Tran described the estimates as the product of design‑level cost evaluation (construction items, right‑of‑way percentages, contingencies, design costs and administration) and said the agreement is intended to transfer construction risk for those improvements to the jurisdiction performing the work once Lake Forest pays its share. He said most of the identified work either is already under contract or budgeted in Lake Forest's capital improvement program.

After discussion the commission moved and seconded a motion to pass item 4 and bring it to a vote; the chair announced the motion passed unanimously. Staff's stated recommendation — that the commission recommend City Council approve the cooperative agreement and authorize the city manager to execute the agreement — will be forwarded to the council for consideration.

Votes at a glance: • Item 3 (consent): Approval of AST Lake Forest summer report — approved unanimously, 5–0. (Moved and seconded during the consent calendar; action recorded at the Oct. 6 meeting.) • Item 4 (discussion): Recommend City Council approve cooperative agreement with City of Irvine for shared LFTMP intersection improvements and authorize the city manager to execute the agreement — commission motion passed unanimously, 5–0.

Ending: The cooperative agreement aims to clarify interagency financial responsibilities and let the jurisdiction performing construction proceed with agreed‑upon mitigation work. The commission forwarded the recommendation to City Council; council action is required to finalize the agreement and transfer funds or authorize execution.