TO: COMMUNITY AND HUMAN SERVICES COMMISSION
FROM: JEREMY SWAN, COMMUNITY SERVICES DIRECTOR
DATE: SEPTEMBER 4, 2024
Reviewed by:
City Manager: n/a
SUBJECT:
Title
REQUEST FOR REMOVAL - BASE LINE ROAD
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SUMMARY
The intersection of Towne Avenue and Base Line Road has experienced a number of collisions over the past several years, with many collisions involving westbound vehicles turning left and eastbound vehicles. To address this collision pattern and improve the overall safety of the intersection, staff will be implementing a traffic signal modification at this location. The modification will include the removal of the existing median on Base Line Road, east of the intersection, and removal of the existing protected-permissive traffic signal operation for east- and westbound traffic, to accommodate the improvements associated with the implementation of a protected-only green arrow phase.
Staff commissioned a traffic study to determine the most effective method to reduce the number of collisions at this intersection. The City’s traffic engineering consultant, Advantec Consulting Engineers, performed the study. In addition to modifying the signal phasing to protected left turns for the east- and westbound directions, the removal of the median on Base Line Road east of the intersection was recommended.
The removal of the existing median along Base Line Road will require removal of thirteen Chinese Pistache trees and transplanting of one Chinese Fringe tree to another location. Although this is necessary to address a safety issue, under current policy a staff level decision to remove the trees is not authorized because all fourteen trees are healthy and stable.
RECOMMENDATION
Recommended Action
Staff recommends the Community and Human Services Commission approve the removal of thirteen Chinese Pistache trees and relocation of one Chinese Fringe tree from the median on Base Line Road, resulting from the provided recommendations to address traffic safety and collision patterns at the intersection of Towne Avenue at Base Line Road.
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ALTERNATIVES TO RECOMMENDATION
In addition to the recommendation, there is the following alternative:
• Refer the matter back to staff for additional information.
FINANCIAL REVIEW
Removal costs are based on a tree’s diameter at breast height. The approximate cost for removal of the thirteen impacted Chinese Pistache trees is estimated at $6,958. The relocation of the Chinese Fringe will be completed at no cost by City staff. Removal costs will be included in the overall project cost and are included in the Capital Improvement Program Budget for 2022-2024, under the Citywide Traffic Signal Improvements Project.
At the July 17, 2024, Tree Committee meeting, Committee members asked staff to look into relocating the thirteen mature Chinese Pistache trees. Staff contacted West Coast Arborists (WCA) for a quote to remove and transplant the trees. WCA quoted $140,000 for relocating the Chinese Pistache trees from Base Line Road to other locations in the City. The quote does not guarantee that the trees would survive the transplant and does not provide a warranty on the trees. If the Community and Human Services Commission recommends moving forward with the tree relocations, this expenditure would come out of the Citywide Traffic Signal Improvements Program budget, which may result in removing from the program other improvements in other areas of the City.
The staff cost to prepare this report is estimated at $1,030 and is included in the operating budget of the Community Services Department.
ANALYSIS
The intersection of Towne Avenue and Base Line Road is a heavily used intersection directly north of the Interstate 210 freeway on/off ramps with particularly high traffic volume during the peak weekday commuter hours. The traffic signal at this location currently operates under a protected-permissive signal operation for the east-west directions. This traffic signal was originally installed by Caltrans when Base Line Road was under their jurisdiction.
At the Towne Avenue and Base Line Road intersection, a number of collisions have occurred between the westbound left-turning traffic and the eastbound through traffic, many of which are associated with the permissive signal phasing. Additionally, the vertical curvature coming eastbound from the Live Oak Canyon Road bridge also contributes to the intersection's dynamics.
Staff commissioned a traffic study for this location, performed by the City’s traffic engineering consultant, Advantec Consulting Engineers, to determine the most effective method to reduce the number of collisions at this intersection. The traffic consultant evaluated collision data provided by the Claremont Police Department, along with a review of the existing conditions. The findings of the traffic study recommend the removal of the protected-permissive traffic signal operation for the east- and westbound left turns and replacement of this traffic signal operation with a protected-only green arrow phase. To enhance safety, this new traffic signal operation also separates the pedestrian phase from the left-turning vehicles. This new phasing should help reduce the left-turn collisions at this intersection.
To address the permissive left-turn collision pattern present at this location and to improve the overall safety of this intersection, staff has been directed to move forward with the recommended traffic signal modification. The modification will be included in the upcoming Citywide Traffic Signal Improvement Project, part of the City’s Capital Improvement Program. The modification will include the removal of the existing median along Base Line Road, east of the intersection, and removal of the existing protected-permissive operation for the east- and westbound traffic, to accommodate the safety improvements associated with the implementation of a protected-only green arrow phase. These recommended improvements have been identified in two different studies. In addition to the Advantec study, the City’s Local Road Safety Plan identified this location to be improved with the proposed safety countermeasures.
Since removal of the existing median along Base Line Road is required, the trees located within the median need to be removed to accommodate the safety improvements. The thirteen trees in question are Chinese Pistache trees, each measuring at least 10 inches in diameter and 15 feet in height. At this time, the trees are considered healthy and stable, free from any pests or diseases. Photos of the thirteen Chinese Pistache trees are included as Attachment A. The City will transplant the fourteenth tree, a Chinese Fringe, to a new location.
CEQA REVIEW
This item is not subject to environmental review under the California Environmental Quality Act (CEQA).
COUNCIL COMMITTEE/COMMISSION REVIEW
At the May 23, 2024, Traffic and Transportation Commission Meeting, Engineering staff presented to the Commission the Base Line Road at Towne Avenue Traffic Signal Modification - Citywide Traffic Signal Improvement Project. Commissioners asked questions of staff and received and filed the report.
At the July 17, 2024, Tree Committee Meeting, the Tree Committee unanimously voted to forward this item to the Community and Human Services Commission for review without a recommendation. The Tree Committee asked for additional information regarding the cost to remove and replant the thirteen Chinese Pistache trees. An excerpt of the draft minutes from this meeting are included as Attachment B.
It is important to note that two additional collisions occurred at this location following these two meetings. Both collisions involved conflicting turning movements.
PUBLIC NOTICE PROCESS
The agenda and staff report for this item have been posted on the City website and distributed to interested parties. If you desire a copy, please contact the City Clerk’s Office.
Submitted by:
Jeremy Swan
Community Services Director
Attachments:
A - Photos of Base Line Road Chinese Pistache Trees
B - Excerpt from the Draft 07-17-24 Tree Committee Meeting Minutes