Title
Recommendation to Authorize the Public Works Director to Install Improvements to the Lincoln Avenue and Walnut Street Intersection, Prohibiting Through and Left-Turn Movements from Walnut Street.
In accordance with the California Environmental Quality Act (CEQA), this action is categorically exempt from further environmental review pursuant to CEQA Guidelines Sections 15301 (Existing Facilities). (Public Works 310)
Body
To: Honorable Mayor and Members of the City Council
From: Adam W. Politzer, Interim City Manager
EXECUTIVE SUMMARY
Staff recommends a pilot project to construct quick-build improvements at the Lincoln Avenue and Walnut Street Intersection which will prohibit through and left turn vehicular movements from Walnut Street with a diverter island, forcing right turns at Lincoln Avenue. The goal of the improvements will be to reduce the high number of broadside collisions that have occurred at this intersection, which is identified as a high collision intersection in the Vision Zero Action Plan. After extensive outreach with the neighbors near the intersection, the proposed improvements were presented to the Transportation Commission (Commission) on January 18, 2026 and the Commission endorsed the project and recommended it to City Council.
The pilot project, if approved, is planned to return to the Commission six months after construction to review traffic and collision data. The pilot project could be made permanent as part of the larger Lincoln-Marshall-Pacific project.
BACKGROUND
Lincoln Avenue is a primary east-west arterial within Alameda with convenient access from the main island to the Park Street bridge and the Miller-Sweeney bridge on Tilden Way. Most of the primary intersections on Lincoln Avenue are controlled with traffic signals including the adjacent intersections of Lincoln/Willow, Lincoln/Oak, Lincoln/Park, and several others along the corridor.
The intersection at Walnut Street is the first non-signalized intersection for vehicles entering the corridor from either the Park Street bridge or from Tilden Way. Right-of-way control is through a two-way stop sign with traffic stopped on Walnut Street.
As part of the Vision Zero Implementation Plan, the Lincoln Avenue and Walnut Street intersection was identified in 2020 as high collision intersection with transformative potential. Many of the collisions reviewed in 2020 were vehicle-to-vehicle broadside collisions occurring as people driving on Walnut Street attempted to turn left onto or to cross Lincoln Avenue.
Prior to 2020, Lincoln Avenue was a four-lane road through the Walnut Street intersection, reducing to a three-lane road (two through lanes and a two-way left turn pocket) as it approached Oak Street. The 2020 improvements extended the three-lane road configuration west and through the Walnut Street intersection. The two eastbound lanes were merged into a single lane approximately 350 feet west of Walnut Street and the single westbound lane extended through the intersection. Dedicated left turn lanes were provided on Lincoln Avenue at the intersection. The intention was to simplify the intersection with fewer through lanes on Lincoln Avenue, improve sight distance for vehicles on Walnut Street, and shorten the effective crossing distance for pedestrians.
All-way stop sign control was evaluated for this intersection in 2020, and based on vehicle counts from late 2019, the intersection did not meet the warrants for a stop sign. The traffic volumes on Walnut Street were not large enough to justify added stop signs. Additionally, the intersection did not meet the warrant for collision experience which is five or more per year. A secondary consideration in the all-way stop evaluation is that the entire Lincoln Avenue corridor is traffic signal controlled and placement of a stop sign at a low volume intersection would likely lead to low compliance from drivers on Lincoln Avenue.
In early 2025, in response to continuing collisions at the intersection and the 2021 pedestrian fatality which occurred at this intersection, the City completed a second round of improvements at the Lincoln/Walnut intersection. Flashing beacons were installed at both crosswalks to alert motorists of pedestrians crossing the intersection. The eastbound lane merge was moved further west, closer to Willow Street, bulb-outs were expanded and painted for increased visibility, and vertical elements (plastic bollards) were added.
Neighbors at the intersection reported multiple vehicle-to-vehicle broadside collisions following the 2025 improvements, providing video evidence from doorbell cameras.
DISCUSSION
High Number of Broadside Collisions
Collision data from 2020 has been augmented by an Alameda Police Department dataset of reported collisions from 2009 through October 2024 and staff completed a preliminary review of the data. There was a total of 38 reported collisions at the Lincoln/Walnut intersection during the nearly 15-year reporting period, the second highest of any intersection within Alameda, and highest of any non-signalized intersection. Nearly 80% of the collisions were reported as broadsides, a collision consistent with vehicles trying to cross an intersection.
The dataset can be further separated into collisions occurring prior to 2020 and those occurring after 2020, comparing the collision rate. While a 7% reduction was observed after 2020, this reduction is similar to the Citywide reduction of 9% in collisions after 2020, and far less than the nearly 40% reduction in collisions observed at intersections where safety measures have been implemented. It is acknowledged that traffic data from this time period was affected by changed traffic patterns resulting from the COVID-19 pandemic. Nonetheless, the traffic data can be used comparatively and provide insights to identify problematic intersections and judge the effectiveness of traffic safety measures.
Anecdotally from neighbor accounts, traffic on Walnut Street has increased since Park Street was reduced from four lanes to two in 2020, with drivers seeking to avoid congestion on both Park Street and Oak Street. These observations, however, were not confirmed with traffic counts collected in late 2025. A comparison between traffic counts collected in 2019 and 2025 show roughly the same order of magnitude with approximately 120 vehicles and pedestrians approaching the intersection from Walnut Street during the AM peak, increasing slightly to approximately 130 vehicles and pedestrians during the PM peak. It is worth noting that the collision rate on the Park Street corridor from San Jose Avenue to Lincoln Avenue has reduced by 33% after 2020, or in other words, a reduction of 43 collisions since 2020.
Not surprisingly, traffic counts collected in late 2025 still do not meet warrant criteria for an all-way stop. The fact that the Lincoln/Walnut intersection continues to see a high number of collisions has prompted staff to evaluate other alternatives to improve safety at the intersection.
Diverter Island to Limit Broadside Collisions
A diverter island, which would restrict through and left turn movements from Walnut Street, was identified as the preferred method and presented to the Transportation Commission for feedback. An example of the diverter island is included as Exhibit 1. The proposed diverter island would restrict vehicular movements only, pedestrians and bicycles could continue north or south across Lincoln Avenue in much the same manner as they currently do. It is recommended that bicycles use the crosswalk and flashing beacons to cross Lincoln Avenue.
Although traffic data do not show a substantial volume increase from 2019 through 2025, it is still likely that drivers are bypassing Park Street or Oak Street and using Walnut Street to access the Park Street bridge. Requiring all Walnut Street traffic to turn right at the intersection would dramatically reduce the potential collision exposure at the intersection and may encourage drivers to remain on Park or Oak Streets when heading to or from the bridge. Additionally, northbound drivers diverted onto Lincoln Avenue would have the opportunity to continue north with a left turn at Oak Street, a signalized intersection. Similarly, southbound traffic diverted onto Lincoln Avenue would have the opportunity to continue south with a left turn at Willow Street, also a signalized intersection.
Alameda Fire Department was consulted and does not have objections to the through and left turn restrictions. Due to its narrow width, Walnut Street is not a primary response route and is typically only accessed by fire trucks for calls on Walnut Street. Additionally, the diverter island would be constructed to allow larger fire truck vehicles to continue through the intersection if needed.
On November 17, 2025, City staff met with the Mayor and interested immediate neighbors at the intersection to observe the afternoon traffic conditions and hear their observations and concerns about the intersection. While traffic speed on Lincoln Avenue was a contributing concern, the primary issue was repeated collisions at the intersection and fear of personal injury and recurring property damage. Stop signs and traffic signals were discussed, and staff presented the diverter island concept restricting through and left turn movements as a quick-build option of a possible phased approach.
A quick-build diverter island can be installed in summer 2026 and observed for several months to a year. Traffic data was collected in December 2025 at three intersections: Lincoln/Willow, Lincoln/Walnut, and Lincoln/Oak to serve as a baseline for traffic movements. Staff would collect traffic data at these same three intersections three to six months after the diverter island was installed to understand how drivers have modified their behavior and evaluate any potential adverse impacts.
Lincoln-Marshall-Pacific Project
Separately, the Lincoln-Marshall-Pacific Safety Improvement Project is in design and on target to begin construction in 2028. If successful, the quick-build diverter island could be made permanent with the larger corridor project. If deemed unsuccessful, staff will continue to evaluate options and pending further warrant analyses, may recommend a full traffic signal be installed at the intersection. It is worth noting that traffic signals are expensive, $800,000 to $1M, would create additional delay for the primary movement on Lincoln Avenue and are not always a panacea to reduce collisions.
Outreach
In addition to the recent on-site meeting with neighbors and ongoing engagement with them, notices were mailed to all residents within 300 feet of the intersection alerting them of the January 28, 2026 Transportation Commission meeting and with additional opportunities to provide comment. Similar outreach was conducted prior to the March 17, 2026 City Council Meeting.
Transportation Commission
Residents in the immediate vicinity of the intersection were strongly supportive of the proposed improvements, strongly asking for the City to identify solutions to reduce the number of collisions at the intersection. After a thorough discussion, the Commission endorsed the through and left turn restrictions on Walnut Street, requesting staff return to the Commission six months after construction to review traffic and collision data.
ALTERNATIVES
• Approve the pilot program to construct quick build diverter island to prevent through and left turn movements from Walnut Street to Lincoln Avenue, with the option to make the improvements permanent as part of the larger corridor project, as recommended by staff.
• Do not approve the pilot and based on assessment of warrants for potential traffic signal installation, direct staff to pursue potential grant funding for a new signal installation. This alternative may take 2 or more years to acquire funding, complete design and construct the improvements.
• Do not approve this proposal and take no action regarding improvements at the Lincoln/Walnut intersection.
• City Council may provide alternative direction to staff for consideration
FINANCIAL IMPACT
Funding for the final design and construction of the quick build diverter island is available in Capital Project C61000, Street Safety. The construction cost is anticipated to be less than $30,000. If the pilot is deemed successful, transition to a permanent installation would be covered in the planned, and much larger, Lincoln-Marshall-Pacific corridor construction project.
MUNICIPAL CODE/POLICY DOCUMENT CROSS REFERENCE
California Streets and Highways Code Section 1800 authorizes the City Council to do any and all things necessary to lay out, acquire, and construct any section or portion of any street or highway within its jurisdiction. In turn, the City Council has delegated significant authority to the Public Works Director to ensure orderly operations of the transportation systems, subject to the City Council’s broader and continuing oversight.
The Vision Zero Policy directs staff to consider safety as the highest priority when balancing competing needs and demands for space within the public right-of-way. The high number of collisions occurring at the Lincoln/Walnut intersection highlights the need for quick action.
General Plan Mobility Element, Goal 2, Safety, is to “Eliminate fatalities and severe injuries on Alameda’s streets, avenues, sidewalks, crosswalks, paths and trails by 2035.” Reducing potential collisions at this intersection supports this goal. Several other General Plan Policies and Actions identify safety for all modes of transit as highest priority.
General Plan Mobility Element Policy MU-13, Alameda Street Grid, calls to “Manage and extend the Alameda street grid to maintain the character of Alameda, reduce traffic, and maximize mobility, access, and safety for all modes of transportation.” While the proposed diverter island would restrict vehicular access across Lincoln and redirect vehicular traffic to the adjacent streets for continuation, pedestrian and bicycle traffic would still be able to cross Lincoln.
ENVIRONMENTAL REVIEW
In accordance with the California Environmental Quality Act (CEQA), this action is categorically exempt from further environmental review pursuant to CEQA Guidelines Section 15301 (Existing Facilities).
CLIMATE IMPACT
The proposed diverter island is predominately a safety project. The proposed project is not anticipated to increase the number of vehicle miles travelled in the City as drivers have readily available parallel routes that cross Lincoln Avenue. The project, therefore, will have negligible climate impact.
RECOMMENDATION
Authorize the Public Works Director to install improvements to the Lincoln Avenue and Walnut Street intersection, prohibiting through and left-turn movements from Walnut Street.
Respectfully submitted,
Erin Smith, Public Works Director
By,
Scott Wikstrom, City Engineer
Financial Impact section reviewed,
Ross MeCarthy, Finance Director
Exhibit:
1. Example Diverter Island