To roundabout or not to roundabout – that’s the question Carlsbad asks as it plans to realign a one-mile section of southern Carlsbad Boulevard, the coastal road also known as road 101.
“In the area near Palomar Airport Road and Las Encinas Creek, southbound Carlsbad Boulevard is at risk from cliff erosion,” a city staff report said. “Periodic flooding of southbound lanes is already occurring, dumping beach sand and rock onto the surface of the roadway and (causing) lane closures.”
The city has proposed three possible boulevard realignments, all of which move southbound lanes east of the beach between Manzano Drive and Island Way. This could happen by eliminating an unusually large landscape median, more than 200 feet wide in places, created decades ago when there was no Interstate 5 and the old 101 was the main road. north-south coast.
Two of the potential realignments would reduce the four-lane highway to one lane in each direction and add up to four roundabouts. A third would retain all four lanes and use traffic lights instead of roundabouts.
According to groups such as the American Society of Civil Engineers, roundabouts improve traffic flow, reduce automobile emissions and are safer for drivers, passengers and pedestrians.
Realignment is needed as erosion has slowly brought the beach closer to the road, a phenomenon that appears to be accelerating with climate change. Parts of Carlsbad Boulevard have already been moved east at least once, and pieces of the original concrete surface can be seen along the cliff near Palomar Airport Road.
“By 2050, there is a high risk of damage to Carlsbad Boulevard from sea level rise due to cliff erosion and flooding,” said Katie Hentrich, senior program manager. of the city, during a recent presentation at city parks. and recreation commission.
“Components of this project have been underway for a number of years, including discussions and analysis regarding pavement alignment,” Hentrich said.
Commission members did not vote on the proposal and made few comments, but some said they liked the ideas presented.
“It’s an exciting project, and I hope it comes to fruition,” said Commissioner Robert Winston.
City Council voted May 5, 2020 to accept a $500,000 grant from the state Coastal Conservancy to pay for preliminary designs for the realignment. These designs are being presented to several city commissions and are expected to be submitted to city council later this year.
One of three proposed options for Carlsbad Boulevard would have roundabouts at the small dirt parking lot north of Palomar Airport Road, Palomar Airport Road, Solamar Drive and Island Way. A second option would use turn lanes at Solamar Drive, but otherwise it’s the same.
Another possible realignment would retain the existing four lanes of traffic, but use traffic lights at each of the four intersections instead of roundabouts.
All realignment options would be designed as so-called “complete streets”, with wider and better protected bike lanes, sidewalks, crosswalks and other features.
The existing southbound lanes of Carlsbad Boulevard on the one-mile segment would no longer be available for vehicular traffic. Instead, the causeway would be converted into a Class 1 cycle and pedestrian path, with access to the beach and parking.
“The idea is to use the area while we have it, before it erodes,” said Carlsbad transportation manager and city engineer Tom Frank.
Class 1 lanes are largely separated from vehicular traffic and are designed for recreational uses such as slow-moving bicycles, skateboarders and strollers, said Tom Frank, director of transportation and city engineer for the city.
“Lyra-clad” cyclists who move faster and ride in groups would be encouraged to use Class 2 cycle lanes in buffered lanes parallel to the realigned carriageway.
Further details on parking, beach access and crosswalks will be worked out after City Council chooses one of three available options, Frank said. Additional grants will be needed.
Carlsbad Boulevard had its first roundabout nearly 10 years ago at the State Street intersection near the Oceanside border.
City Council approved another roundabout in 2018, by a 3-2 vote, with Mayor Matt Hall and Councilman Keith Blackburn opposing it, to be installed on Carlsbad Boulevard and Cannon Road. Construction is scheduled for 2026 as part of the Terramar Region Coastal Improvement Project.
Another roundabout has been proposed as one of several options for pedestrian-oriented improvements planned for the intersection of Carlsbad Boulevard and Tamarack Avenue.
However, city officials said recently that the Tamarack project has been delayed by environmental and technical complexities, and that more work is needed before the council will choose one of the options.