Title
Discuss the Citywide Roundabout Analysis (Gail Payne, Senior Transportation Coordinator and Mike Alston, Kittelson & Associates, Inc.) (Discussion Item)
Body
To: Honorable Chair and Members of the Transportation Commission
BACKGROUND
Roundabouts can be an important tool in the implementation of the Vision Zero policy, which prioritizes the reduction of fatal and severe injury crashes to zero. In November 2019, the City Council adopted a resolution establishing Vision Zero as the City’s guiding principle for transportation planning, design and maintenance. In 2021, the City Council approved the Vision Zero Action Plan, which includes specific actions and policy changes to increase street safety in Alameda. The Vision Zero webpage is at www.alamedaca.gov/VisionZero <https://www.alamedaca.gov/VisionZero>
Roundabouts reduce the types of crashes where people are seriously hurt or killed by 90 percent when compared to conventional stop-controlled and signalized intersections. Roundabouts result in lower vehicle speeds, generally 15-25 miles per hour, around the roundabout. Crashes that occur will be less severe because of this reduced speed. Pedestrians are generally safer at roundabouts, and are faced with simpler decisions at a time. Roundabouts also reduce delays compared to traffic signals, provide landscaping and flood reduction opportunities, and have lower maintenance costs.
Due to the benefits of modern roundabouts, the City’s Annual Report on Transportation (January 2021) stated that staff would hire Kittelson to provide an educational presentation on roundabouts, to identify top locations for potential roundabouts, to peer review the proposed Central Avenue roundabouts, and to add policies related to roundabouts in the General Plan update. The first amendment of the agreement included an evaluation of the Mecartney Road/Island Drive intersection for a potential roundabout, a peer review of the proposed roundabout at Sherman Street/Encinal Avenue/Central Avenue with potential right-of-way acquisition and grant writing, which was switched to a screening of roundabouts in the Lincoln Avenue/Marshall Way/Pacific Avenue corridor.
As a second amendment to the Kittelson contract on roundabouts, Kittelson is:
1) Completing the citywide roundabout screening analysis, which is the purpose of this agenda item;
2) Developing a concept for the Clement/Tilden Improvement Project;
3) Continuing with peer reviews for the Central Avenue and Lincoln Avenue/Marshall Avenue/Pacific Avenue Safety Improvement Projects; and
4) Developing roundabout concepts to prepare projects for grants, design and environmental clearance, which is the next steps part of the staff report.
DISCUSSION
This discussion section highlights work done to date on modern roundabouts including: 1) an education presentation, 2) a status on the Central Avenue/Sherman Street/Encinal Avenue proposed roundabout regarding right-of-way acquisitions, 3) roundabout policies in the General Plan; 4) a citywide screening for potential roundabouts (purpose of this staff report), and 5) next steps on grant writing.
1) Roundabout Education
As part of Vision Zero safety, staff contracted with Kittelson consultants to provide an educational presentation on roundabouts. On January 27, 2021, the Transportation Commission focused on roundabout education with the presentation as Exhibit 1 and the video link shown here and starting at the 30 minute mark: <http://alameda.granicus.com/MediaPlayer.php?view_id=6&clip_id=2716>
Modern roundabouts are a type of intersection characterized by a generally circular shape, yield control on entry, and features that create a low-speed environment while traveling counterclockwise around a central island. Mini-roundabouts are a type of roundabout characterized by a small diameter and traversable islands, and are best suited to environments where speeds are already low and environmental constraints would preclude the use of a larger roundabout with a raised central island. Modern roundabouts have been demonstrated to provide a number of safety, operational and other benefits when compared to other types of intersections including as follows:
• Traffic Safety: The physical shape of roundabouts reduces potential conflict points and the most severe of those conflict points.
• Pedestrian and Bicyclist Safety: The splitter island refuge area allows people walking and bicycling to focus on one traffic stream at a time while crossing. Specific design treatments for visually impaired pedestrians need to be implemented while including these community members in the design and construction process.
• Traffic Calming: Roundabouts reduce vehicle speeds using design rather than relying on traffic control devices.
• Operational Performance: Roundabouts typically have lower overall delay than signalized and all-way stop-controlled intersections, and the reduced delay is often most significant during non-peak traffic periods. These performance benefits can often result in reduced lane requirements between intersections.
• Operations and Maintenance: Roundabouts typically have lower operating and maintenance costs than a traffic signal due to the lack of technical hardware, signal timing equipment and electricity needs. Roundabouts provide cost savings to society due to the reduction in crashes, particularly fatal and injury crashes.
• Environment: Roundabouts can reduce vehicle delay, the number and duration of stops and impermeable surface area, which can reduce noise and air quality impacts and fuel consumption and can increase the space for green stormwater measures such as bioswales.
• Aesthetics: The central island and splitter islands provide attractive gateways or centerpieces for communities through the use of landscaping, monuments and art.
Source: Federal Highway Administration, Roundabouts: An Informational Guide
2) Sherman Street/Encinal Avenue/Central Avenue Proposed Roundabout
On April 20, 2021, City Council directed the staff and the CDM Smith consultant team to consider a right-of-way (ROW) purchase of the adjacent gas station property area to allow for a full access roundabout at the Sherman Street/Encinal Avenue/Central Avenue intersection that would not restrict travel movements as does the City Council approved Slip Lane option, which restricts northbound travel movements going straight on Sherman Street. After conducting this analysis, staff continues to recommend the Slip Lane option because the gas station area ROW purchase would not allow for a full access roundabout that meets national safety guidelines (Exhibit 2). To meet these safety guidelines, multiple residential properties in the southwest corner would need to be purchased and then demolished to construct a full access roundabout, which is not recommended. In a peer review, Kittelson concurred with the recommendation to continue with the City Council approved Slip Lane option. The City Engineer concurs with the memorandum. Thus, staff and the consultant team continue to design the Slip Lane option, and also continue to seek funding to construct it as part of the Central Avenue Safety Improvement Project. The project webpage is www.alamedaca.gov/Central <http://www.alamedaca.gov/Central>
3) Roundabout Proposed Policies in the General Plan
Staff requested that Kittelson provide policies related to roundabouts to incorporate into the General Plan (www.alameda2040.org <http://www.alameda2040.org>), which was approved last year. The General Plan mentions roundabouts as follows:
• Spotlight on Roundabouts: Highlights the benefits of roundabouts similar to the above summary in the educational section of this staff report.
• ME-7: Safe Streets:
o “e. Roundabouts. Increase the use of roundabouts at intersections to improve the safety and lower maintenance costs compared to traffic signals.”
o “j. Intersection Safety. To improve safety at a stop controlled or signalized intersections, consider a roundabout design or eliminating right turns on red and adding pedestrian scrambles to existing signals.”
o “k. Roundabouts and Traffic Circles. When considering modification to an intersection, prioritize roundabouts and traffic circles for consideration recognizing that land acquisition needs, operational considerations, or other engineering factors or constraints may result in other intersection solutions on a case-by-case basis.”
4) Citywide Screening Analysis for Potential Roundabouts
Exhibit 3 shows the results of the initial citywide analysis to identify the top locations for potential roundabouts with a focus on high injury corridors and high crash intersections. Exhibit 4 describes the analysis for the remaining locations in the City. Exhibit 5 shows a map of all the potential locations in the City where roundabouts are possible using the existing public street right-of-way. The roundabout locations were selected by using the following screening criteria that align with the four general plan goals as well as a category for “strength weakness opportunity threat (SWOT)” as shown in Exhibit 6:
Goal 1 - Equity: Used the San Francisco Bay Conservation and Development Commission equity priority area screening with highest score as five points if adjacent to an equity priority area.
Goal 2 - Safety: Used the high injury network corridor and intersection screening with highest score as ten points if on both a high injury corridor and intersection.
Goal 3 - Choices: Provided two points each if on a bus route, existing and planned bikeway and truck route for a maximum of six points.
Goal 4 - Sustainability: Based on sea level rise inundation areas with a maximum score of five points.
SWOT - Strength, Weakness, Opportunity and Threat: Gave a negative score of five points if on a Caltrans facility and a positive five points if at a signal location to help with signal modernization priorities.
The combined locations for roundabouts are grouped as follows to better understand how to proceed with next steps:
High Priority Locations
• High Street/Fernside Boulevard (recommend for high-crash grant application)
• Marina Village Parkway/Constitution Way (recommend for high-crash grant application)
• Stargell Ave/Mariner Square Loop (recommend for high-crash grant application)
• Encinal Avenue/Fernside Blvd (unfunded; recent signal work expected to improve safety)
• Main Street/Willie Stargell Avenue (unfunded, potential for adjacent new development in Alameda Point to construct)
• Atlantic Avenue/Main Street/Appezzato Parkway (unfunded, could be added to the Appezzato Parkway Bus Improvement Project)
• Atlantic Avenue/Constitution Way (unfunded; recent signal/path work expected to improve safety)
• Island Drive/Robert Davey Jr. Drive (not a high-injury corridor or intersection)
City Council Approved
• Central Avenue/Main Street/Pacific Avenue (funded)
• Central Avenue/Third Street/Taylor Avenue (funded)
• Central Avenue/Fourth Street/Ballena Blvd. (unfunded) (recommend for Central Avenue roundabout grant application)
• Central Avenue/Sherman Street/Encinal Avenue (unfunded) (recommend for Central Avenue roundabout grant application)
• Otis Drive/Grand Street (unfunded; recent work expected to improve safety)
Evaluation in Process
• Tilden Way/Blanding Avenue/Fernside Blvd. (part of the Clement Avenue/Tilden Way Safety Improvement Project; webpage: www.alamedaca.gov/ClementTilden <https://www.alamedaca.gov/ClementTilden>) (funded)
• Mecartney Road/Island Drive (recommended for City Council approval by the Transportation Commission in March 2022; request for City Council approval is expected on June 21, 2022; webpage: www.alamedaca.gov/MecartneyIsland <http://www.alamedaca.gov/MecartneyIsland>) (unfunded; potential funding from Transportation Impact Fee)
5) Next Steps
The City staff/Kittelson consultant team is seeking input on the citywide screening analysis to assist with next steps on grant writing for the highest priority roundabouts. The Alameda County Transportation Commission has a call for projects with grant applications due on June 30, 2022. The input received at the Transportation Commission will help guide the development of roundabout concepts for the grant applications. City staff is expected to submit two different roundabout grants or one combined roundabout grant as follows and consistent with the Annual Report on Transportation (January 2022):
1) Safety Improvements at High Crash Intersections - Roundabouts for consideration to submit include:
• High Street/Fernside Boulevard
• Marina Village Parkway/Constitution Way
• Stargell Ave/Mariner Square Loop
2) Central Avenue Roundabouts - Roundabouts for consideration to submit include:
• Central Avenue/Fourth Street/Ballena Blvd.
• Central Avenue/Sherman Street/Encinal Avenue
Furthermore, City staff/consultant team also is developing a concept for the Clement Avenue/Tilden Way Improvement Project with initial findings that include a proposed roundabout. The project webpage is www.alamedaca.gov/ClementTilden <http://www.alamedaca.gov/ClementTilden>
FINANCIAL IMPACT
The citywide screening analysis for roundabouts is funded by Measures B/BB Local Streets & Roads (20962743), Alameda County’s transportation sales tax, which is administered by the Alameda County Transportation Commission.
MUNICIPAL CODE/POLICY DOCUMENT CROSS REFERENCE
This action is in conformance with the Alameda Municipal Code and all policy documents, and is consistent with the Transportation Choices Plan (2018) and the Climate Action and Resiliency Plan (2019). Roundabouts are consistent with the General Plan (2021) and makes progress towards meeting the four goals of the Mobility Element, which are as follows:
Goal 1 - Equity: Provide for the mobility needs of all Alameda residents, workers, and visitors regardless of income, age, ability, or neighborhood.
Goal 2 - Safety: Eliminate fatalities and severe injuries on Alameda’s streets, sidewalks, crosswalks and trails by 2035.
Goal 3 - Choices: Expand and improve alternatives to low occupancy automobile trips to incentivize mode shift to more environmentally sustainable modes of transportation while recognizing the diverse needs for mobility.
Goal 4 - Sustainability: Reduce the impacts of transportation systems on the environment, and transition to a more resilient transportation system to address the impacts of climate change.
Roundabouts are supported in the Mobility Element under ME-7, the Safe Streets section as follows:
e. Roundabouts. Increase the use of roundabouts at intersections to improve the safety and lower maintenance costs compared to traffic signals.
j. Intersection Safety. To improve safety at a stop controlled or signalized intersections, consider a roundabout design or eliminating right turns on red and adding pedestrian scrambles to existing signals.
k. Roundabouts and Traffic Circles. When considering modification to an intersection, prioritize roundabouts and traffic circles for consideration recognizing that land acquisition needs, operational considerations, or other engineering factors or constraints may result in other intersection solutions on a case-by-case basis.
Vision Zero Action Plan (2021) action 4.6 calls for the City to “Conduct a citywide intersection study to determine suitability for roundabouts to increase safety by slowing vehicles, eliminating broadside crashes, and decreasing conflicts.”
ENVIRONMENTAL REVIEW
This action is not a project under Public Resources Code section 21065 and California Environmental Quality Act Guidelines section 15378(b)(4).
CLIMATE IMPACT
The roundabouts analysis effort will further the implementation of the Transportation Choices Plan (2018) and the Climate Action and Resiliency Plan (2019) to improve transportation operations and to reduce greenhouse gas emissions.
RECOMMENDATION
Discuss the Citywide Roundabout Analysis.
Respectfully submitted,
Gail Payne, Senior Transportation Coordinator
Exhibits:
1. Roundabout Education Presentation
2. Central Avenue/Sherman Street/Encinal Avenue Roundabout Evaluation
3. Citywide Roundabout Screening and Feasibility Memorandum (High Injury)
4. Citywide Roundabout Screening (Full City Analysis)
5. Citywide Roundabout Screening Map
6. Citywide Roundabout Rankings Spreadsheet