Business Item 5b
STAFF REPORT
City Council Business Item
DATE: April 7, 2025
TO: Honorable Mayor and Council Members
FROM: Brendan Byrd, City Engineer/Public Works Director THROUGH: Amy Nilsen, City Manager
SUBJECT: Approval of a Project Study Report for the Kenmar and Ross Hill Road Intersection Improvement Project
STAFF RECOMMENDATION:
Receive staff presentation and recommendation to approve a Project Study Report (PSR) for the Kenmar and Ross Hill Road Intersection Improvement Project and provide staff direction on the Council preferred project alternative.
EXECUTIVE SUMMARY:
As the Council is aware, since the 2010 General Plan, the City has been working towards identifying improvements for key transportation infrastructure in the City of Fortuna. Most notably, the City’s focus has been to improve the interchanges with Highway 101 at 12th Street and Kenmar, with a preliminary alternative analysis being completed in 2016, and initial project phase funding being secured for the projects in 2018, 2022 and 2024. After the City secured funding for the 12th Street Preliminary Design phase in 2022, staff shifted some focus to the City’s Kenmar and Ross Hill Road intersection, which also has issues with traffic level of service, vehicle queueing, non-motorized connectivity, safety and the ability to handle traffic volumes as the City continues to develop.
In 2022, staff worked with the City’s on call traffic engineer, GHD, to develop a scope and budget for a project study report for the Kenmar and Ross Hill Road Interchange (PSR). The intent of the Project Study Report is to analyze preliminary improvement alternatives, ultimately with the hopes of being able to identify a preferred project alternative to move forward into budgeting and engineering design. The PSR looks holistically at the project and covers areas including existing conditions traffic analysis, alternatives development, proposed conditions traffic analysis, environmental constraints, costs and impacts to rights-of-way. Another benefit of developing this report is that is makes this project eligible for funding through the State Transportation Improvement Program (STIP), which is the City’s primary available funding source for projects of this scope and scale. The Council approved a supplemental budget request for this report in 2022, at which time staff began working with GHD to complete the project.
The PSR was largely completed by late 2023, however, given the continued progress and changes occurring on the City’s Kenmar Interchange and Mill District Specific Plan projects, staff held back on finalizing the PSR to make sure that the proposed improvements were able to account for and be compatible with what was being proposed in those two areas. Now with both the preliminary design being completed on the Kenmar Interchange Project, and the Mill District Business Item 5b
Specific Plan being approved, staff are ready to bring the final draft PSR to the Council for review and approval. The draft project alternative figures have been extracted from the report and are included as Attachment A. The entire final draft PSR is included as Attachment B. Below staff have developed a summary of the proposed project alternatives.
Existing Intersections Problems
This section lists the primary issues that have been identified at the existing signalized intersection.
In the alternative section below, each alternative is noted for how well it addresses these existing issues.
1. Intersection Level of Service – level of service (LOS) is a measure of how long a vehicle waits to move through an intersection. LOS is measured in ‘grades’ between A-F, with A being a low amount of time, and F being a long time. The existing intersection operates at an average LOS of D in the AM peak hours, and a LOS of C in the PM peak hours. The Fortuna General Plan currently calls out minimum LOS standards for this intersection of D. Based on future traffic modelling as the City grows, each intersection leg is projected to operate at LOS E in the future, which is below the General Plan target (without improvement).
2. Intersection Queuing – the existing intersection currently has issues with excessive vehicle queue, most notably for the northbound left movement (residents leaving Campton Heights to go to the freeway), and the eastbound Kenmar movements (residents entering town from the freeway). Queus routinely backup to Eel River Drive on Kenmar, or beyond the turn pocket on Ross Hill Road.
3. Safety Considerations – the existing intersection has two primary areas which the City routinely receives complaints for unsafe conditions. The first and most noticeable is the ‘slip lane’ that bypasses the signalized intersection, allowing southbound traffic on the boulevard to immediately access Kenmar Road. At the merger, movement there are often conditions where vehicles do not follow the yield requirements. The second is the southbound merge lane moving up Ross Hill Road. Currently because there are two southbound lanes at the intersection, merging to one on the other side of the intersection, southbound drivers tend to compete with one another to successfully make the merger on the other side of the intersection.
4. Bicycle and Pedestrian Connectivity – while the existing intersection has bike lanes connecting the north/south lanes, there are no dedicated facilities on the east/west lanes.
Additionally, the crosswalks that lead pedestrians towards the freeway end at the City’s main median island, where there are no additional facilities to get non-motorized users to the north side of Kenmar Road.
5. Design Life – as noted above, the intersection is near or at its useful design life, with LOS soon to be unacceptable by current City standards. Intersection requires improvement.
Improvement Alternatives Identified
The following sections describe each of the three alternatives that were explored in the PSR. The final section notes how each of the alternatives compare to each other based on the existing intersection problems noted above.
Minimum Build – Signalized Intersection Retrofit
This minimum build project alternative would include several intersection alterations aimed at addressing as many of the intersection problems as possible for a lower project cost. Project components would include adding an additional inbound lane on eastbound Kenmar, which would help significantly reduce AM and PM peak hour vehicle queues. The southbound left turn pocket Business Item 5b
on South Fortuna Boulevard would also be extended to accommodate more vehicles. The ‘slip lane’ to westbound Kenmar is also proposed to be removed, and one of the southbound lanes on the Boulevard would be converted into a right turn onto Kenmar Road at the signal. This alternative would include no improvements to the northbound Ross Hill Road traffic, and therefore operations and future issues would continue to be an issue under this alternative. This alternative is graphically shown in Figures 1-2 of Attachment A
Maximum Build – New Signalized Intersection
This alternative would include reconstructing the entire signalized intersection to current design standards while accommodating for projected future traffic volumes. This alternative is graphically shown in Figures 3-4 of Attachment A. For this alternative widening would be required beyond the paved limits on all legs of the intersection. Additionally, given the widening required on Kenmar Road in between the intersection and the highway, the project would likely include some encroachment into the creek channel (and therefore some potential realignment), and the replacement of the main box culvert that takes Mill Creek beneath Kenmar Road.
Maximum Build – Roundabout
The final alternative identified would reconfigure the entire signalized intersection into a roundabout, like what is being proposed for the Kenmar and 12th Street Interchanges. This alternative is graphically shown in Figures 5-6 of Attachment A. As shown the roundabout would almost entirely fit within the existing paved limits, with only minor widenings required on the City-owned medians near the Gateway Sign and on the east side of the intersection. One key difference of this roundabout as compared to the ones proposed at the highway interchanges is that due to traffic volumes, the northbound Ross Hill Road/Fortuna Boulevard movement has two entry lanes. As such, although still standard in roundabout design and construction, there would be more complexity to the operation of this roundabout than a conventional single-lane roundabout.
Comparison of Alternatives
The table below provides a comparison of how each of the proposed alternatives addresses the main existing issues noted above. It should be noted that this table is not included in the PSR, this has been developed by staff to help aid the Council and the public in understanding the tradeoffs for various alternatives.
Business Item 5b
Table 1. Comparison of project alternatives.
Alternative Estimated
Cost
Average
Level of
Service
Queuing Safety Non-Motorized
Accessibility Design Life1
Minimum Build
Signal $2.9 M C/D
Medium – almost all movements
contained within available
intersection storage, with the
exception of northbound traffic
on Ross Hill Road. Kenmar
operations do not impact
highway interchanges
Medium to
Good
Medium – improves
east/westbound bike and
pedestrian accessibility
20-30 years for
improved portions,
less for
unimproved
portions
(northbound Ross
Hill Road)
New Signalized
Intersection $12.6 M C
Medium – almost all movements
contained within available
intersection storage. Kenmar
operations do not impact
highway interchanges
Good
Good – bicycles and
pedestrians serviced for all
routes
30-50 years
New
Roundabout $8.7 M A Minimal – none exceeding available storage Good Good – bicycles and
pedestrians serviced for all
routes
50-year or beyond
1. Estimated based on engineering judgement. Current PSR only projects traffic volumes through 2045.
Business Item 5b
Staff recommend that the Council approve the PSR, which would finalize the document and position the City for future STIP funding for this project. Staff would also recommend that the Council provide staff with direction on a preferred project alternative to pursue, taking into consideration the comparison of alternatives provided above.
FINANCIAL IMPACT:
The PSR was completed under a previous budget allocation of $44,000 that was approved by the Council in 2022. Unless the Council is requesting changes to the PSR or alternatives developed, approval of the report will have no further budgetary impact.
Future fiscal impacts that will result from the PSR specifically pertain to the preferred improvement alternative identified by the Council. As shown in the table in the executive summary section, or in the PSR itself, future costs for project improvements range from approximately $2.5 million to $11 million. With a preferred alternative identified, staff will work to develop a funding plan. The first major funding opportunity that could be leveraged to advance the next stage of this project will be the 2026 STIP funding, which is due for programming through HCAOG later this year.
RECOMMENDED COUNCIL ACTION:
1. Receive staff presentation and review Council questions with staff
2. Open Public Comment
3. Close Public Comment
4. Motion to approve the Project Study Report for the Kenmar and Ross Hill Road Intersection Improvement Project. Voice Vote.
ATTACHMENT:
• Attachment A – Project Alternative Figures
• Attachment B – Draft Project Study Report