Tuesday, March 19, 2024

Coronado Voices: Adding Traffic Signals – Analysis from the Coronado Transportation Commission


As Chair and Vice-Chair of the Coronado Transportation Commission (CTC), we are sworn under Ordinance 2021 to support the policy of the City Council to “improve the quality of life for those that live, visit, and work in Coronado through quantifiable traffic calming and other transportation solutions” and to “explore potential short-term and long-term methods to reduce the impact of traffic congestion on residents.”

For the better part of three years we have studied, received public input and worked with professional engineering consultants to examine options for improving safety throughout, mobility across and calming traffic within the Third and Fourth Streets corridor. Our recommendations will be considered by the City Council on October 6, 2015. They are based on factual data, input from residents, traffic engineering principles and expert consulting engineering input.

The corridor typically experiences over 40 traffic accidents annually (one every 9 days). The City’s Annual Traffic Reports for 2009-2013 (the five most recent reports available) indicate that 68% of all accidents in Coronado’s Village occurred at unsignalized intersections.

According to SANDAG, the Third and Fourth Streets couplet (measured in both directions at the bridge) carries more traffic daily than any other state highway in San Diego County that is not designated a freeway – and, of course, the couplet between the bridge and the base is a residential neighborhood. The streets are used by almost 80,000 cars per day, even higher when multiple aircraft carriers are in port. These streets are state highways whose design and maintenance falls outside of Coronado’s control. Caltrans has been a partner in some work while being reluctant to grant exceptions to its design manual for some improvements recommended by the City.

Potential corridor traffic improvements have been evaluated over many years. Based on our assessment and the input of residents, CTC recommended to City Council to retain a professional engineering consultant to examine options, including current traffic calming design elements and approaches, to manage congestion and improve safety in the corridor. The CTC engaged the residents in the corridor even before the consultant’s scope of work was drafted to be sure the work would be consistent with residents’ desires. CTC invited over 2,000 online surveys from corridor residents and 300 surveys were submitted. Based on the survey results the CTC, working with City staff, developed a scope of work, and the City hired Fehr & Peers following a competitive consultant selection process. Fehr & Peers is nationally recognized for its expertise in transportation engineering. Among the major concerns expressed by the residents were:

  • Speeding on Third and Fourth Streets
  • Failure of motorists to yield to pedestrians and bicyclists
  • Traffic noise
  • Difficulty crossing/turning on to Third and Fourth Streets from side streets.

The consultant conducted two public workshops and an online survey to gauge resident input as part of the study process. During this time it became clear that there were concerns by some residents outside the corridor that improvements within the corridor might lead to potential increases in traffic on their streets. In response to these concerns the CTC requested that the consultant evaluate them further. The results of that analysis showed that traffic would not increase southbound from Fourth Street on A, B or C Avenues since the travel time on Pomona Avenue is much less due to the presence of STOP signs at most intersections on A, B and C Avenues between Fourth and Tenth Streets. In addition, the CTC recommended other actions to restrict turns to limit vehicles from using certain streets at peak times, so there would be little or no increase in traffic above current levels. This approach is like many similar restrictions currently in effect in Coronado.

Based on residents input, data collection and analysis, the consultant developed 18 recommendations for improvements, including speed tables, raised cross walks and other traffic calming approaches to reduce speeding and improve overall corridor safety. The consultant also recommended traffic signals at seven intersections.

Some people have questioned how traffic signals can improve both safety and traffic flow simultaneously. Traffic signals are among the most cost-effective tools to reduce congestion, reduce the frequency of accidents, and provide for orderly traffic movement by interrupting heavy traffic at intervals to allow pedestrians, bicyclists and connecting-street traffic to cross.

Traffic engineering is not always intuitive. It is an applied science that requires education, training and experience. Sophisticated computer models are needed to fully analyze various options. The consultant demonstrated via graphical computer simulations at public meetings, how the proposed signals would improve traffic flow and safety in the corridor.

Unfortunately, the impact of traffic signals have been misrepresented or misunderstood by some who, characterize their use and effectiveness directly opposite from the facts and demonstrated usefulness shown by the consultant. The next step proposed by the CTC will be “preliminary engineering” to evaluate the effectiveness of traffic signals at five intersections while avoiding negative impacts in adjacent neighborhoods – as clearly stated in CTC’s recommendations to the City Council made at CTC’s June 11, 2015 meeting.

A local example of effective use of traffic signals is the couplet of Grape and Hawthorn Streets in San Diego between I-5 and the Harbor Drive. Traffic usually flows smoothly at 25 mph through this business district yet allows safe crossing of these streets due to the signals. As a matter of interest, the average traffic of this couplet is less, by 20,000 cars per day, than the Third and Fourth Streets couplet in Coronado based on SANDAG data!

Some have made the argument that traffic signals are inappropriate in residential neighborhoods. The necessity of traffic signals is determined by many factors: traffic, accidents, sight distance, etc. There exists a specific process to determine whether a traffic signal is “warranted” based on objective principles. The five proposed locations recommended by the CTC appear to qualify–a fact to be confirmed by follow-on preliminary engineering. Traffic signals exist in residential neighborhoods all over the county, state and country.

Upon receipt of the consultant’s report and recommendations, the CTC conducted a detailed review while also reaching out to many community groups – Rotary, Chamber, MainStreet, Optimists, Third and Fourth Street residents, Naval Base Coronado, and others to describe the consultant’s recommendations and obtain feedback. City-wide meetings were held at the Community Center and Winn Room.

As part of its evaluative process, the CTC invited a representative of Caltrans to discuss the possibilities of adopting some of the consultant’s traffic calming recommendations on Third and Fourth Streets. While not ruling them out completely, the rep noted that Caltrans has never approved similar improvements (i.e., raised cross walks and speed tables) anywhere in California on state highways. The CTC fully recognizes that the corridor is traversed by a state highway couplet, and we are equally cognizant that the couplet is a residential neighborhood and that the safety of all users (pedestrians, bicyclists and motorists whether residents or visitors) transcends all other considerations.

Based on the final report from Fehr & Peers and a broad cross-section of public input, the CTC voted unanimously to recommend to City Council that the next step in the process should be to perform preliminary engineering on the recommendations identified by the CTC, and to continue the collaborative process with Caltrans and the residents.

The CTC requested that the preliminary engineering should specifically include analyses to identify solutions that will limit diversions of traffic to existing levels from the City’s major and minor arterials on to collector and local streets. This can be done by turn restrictions and other methods currently in use in Coronado. This appears to us to be a reasonable, measured approach. The preliminary engineering would also be essential for the City to engage Caltrans in further discussions about long-term solutions to the corridor’s traffic calming, mobility and safety challenges.

Much has changed in Coronado since the bridge opened in 1969. We think the time has come for a thoughtful, careful analysis of ways to make improvements that will make life better for residents in the corridor, other residents whose neighborhoods are impacted by the corridor and all Coronado’s citizens, commuters and visitors. We believe in the words of the ordinance that created the CTC and hope the City Council agrees.

Respectfully,

Patrick Garahan, Chair

John Moutes, Vice Chair

 

Professionally, the authors are licensed Civil Engineers, each having over 40 years of experience in advising public agencies and municipalities. Garahan served as Secretary of Transportation for the State of Vermont, as well as commissioner of public works for a city in Vermont of comparable size to Coronado. He is also a licensed Traffic Engineer in California.

 

 



Coronado Times Staff
Coronado Times Staff
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