CARLSBAD — The city is moving forward with plans to install a trio of roundabouts along Carlsbad Boulevard from Palomar Airport Road to Island Way.
The council unanimously approved one of three options to realign Carlsbad Boulevard, creating a two-lane road with three roundabouts at Palomar Airport Road, Solamar Drive and Island Way.
The South Carlsbad Boulevard Climate Adaptation Project marks the first major review of the city’s infrastructure related to sea-level rise. The study also looks at Las Encinas Creek restoration and a cliff erosion assessment.
The study is funded by a grant of more than $500,000 from the State Coastal Conservancy in October 2021. The study, conducted by the Scripps Institute of Oceanography, will focus on sea-level rise and how to move the road’s southbound lanes eastward away from the ocean and out of a hazard zone.
“Not all streets have the same purpose,” said Kaite Hentrich, a senior program manager with the city. “Carlsbad Boulevard falls under a coastal street and means it’s designed to move people, not just cars. It does not need to be the highway it once was.”
The grant runs through February 2024, and staff will return in March 2024 for another update on the study, conceptual design and options regarding retreating coastline infrastructure.
According to staff, the next steps are to conduct a 30% conceptual design, however, no funds from the grant can be used for environmental reviews or construction.
Tom Frank, the city’s transportation director, said the coastal hazard zone is designated through 2100 and extends west of most of the project area. Decades from now, the Solamar Drive intersection could revert back to a signalized intersection depending on the advancement of erosion.
Frank said the study shows the Solamar Drive bluff is the most prone to large-scale erosion.
The council will review retreat options for the current infrastructure, along with removing the southbound lanes once the project is funded. Once those lanes are removed, the city could install native plants and other measures to mitigate erosion and protect against flooding and sea-level rise, staff reported.
Frank said the roundabouts provide the safest and most efficient option to manage the roadway, including motorists, cyclists and pedestrians, reduce conflict points, and act as a conduit to congestion from Interstate 5. The realignment will also add a roadway buffer to protect from flooding at the Las Encinas Creek.
“We are improving roadway conditions,” Frank told the council. “We would not be producing something that would be reducing traffic capacity without presenting that to you.”
Steve Linke, a former Traffic and Mobility commissioner, said the amount of traffic at the current Palomar Airport Road “interchange” pushes the limits of what can be squeezed into a single-lane roundabout, along with other intersections along Carlsbad Boulevard.
When roundabouts reach capacity, they fail catastrophically with gridlock much worse than signalized intersections, Linke said.
According to Linke, due to scope and cost, the overall project should go to a public vote as demanded by Proposition H rather than “piece-mealing it into numerous small projects” and using up substantial portions of transportation funding.
“In addition, despite staff’s continuing bombardment with generic, out-of-context roundabout safety claims, the roundabouts in this area have proven to have the highest collision frequencies — including severe injury collisions and involvement of pedestrians and cyclists,” Linke said. “While this is inconvenient to roundabout enthusiasts who think that single-lane roundabouts are a cure-all for nearly every situation, it is a fact that needs to be acknowledged.”
