Changes to Carlsbad traffic analysis coming

CARLSBAD — Traffic has long been a major source of frustration and contention among residents in the city.

During its July 9 meeting, the City Council took a report from city staff regarding new methodologies and the identification of six street segments not meeting the 2015 Growth Management Plan (GMP) circulation standard.

The item will come back to the council on July 16 for action regarding alternative options for the traffic impact analysis methodologies.

“The focus was building out the system and adding the capacity,” David de Cordova, a principal planner with the city, said about the GMP. “Nearly all the major streets have been completed.”

The city’s analysis has long been questioned, notably with exempting smaller infill developments from the traffic impact analysis. The current system was put in place in 1986 with an “A” through “F” rating system as one measuring stick.

One condition is a road or intersection in a specific Local Facility Management Zone cannot exceed a service level of “C” during off-peak hours or a “D” or lower during peak hours, de Cordova said.

He said three deficiencies occurred — in 1991, 1998-99 — and development was stopped until they were identified and addressed.

Many have challenged the city’s analysis throughout the years, especially after the passage of the General Mobility Element in 2015.

Steve Linke, who was appointed to the Carlsbad Traffic Safety Commission in March, said the issue stems from the city not using correct analysis for years and urging the council to adopt new measures.

“I think the main problem right now is there is so much inconsistency between departments and within departments in the city with their applying different methods,” he said. “We need to have the advisory commissions review all the methods to make sure they are valid. And advise the council to formally adopt those.”

He said the city’s current methods overestimate the capacity of roads leading to failures, also known as congestion and traffic jams. In fact, he said, two other analysis methods show Carlsbad’s grades are on the lower end of the spectrum, such as “D” and “E,” rather than the “A” and “B” ratings reported over the years.

He said the capacity of a lane on a road hasn’t changed, so the method used in 1986 was used for rural highways, not urban streets.

“They used the wrong chapter of the Highway Capacity Manual …  of what you use to determine what the capacity of a road is,” Linke added. “They chose one that is extremely exaggerated. The threshold was so high … that you could never get anything but a passing grade.”

From the manual, Carlsbad uses 1,800 vehicles per hour, per lane, which the staff report said was acceptable when adopted. However, Senate Bill 743 and Assembly Bill 1358 have changed how cities approach traffic.

Another change is using vehicle miles traveled for level of service, along with 500 to 1,000 cars per lane, per hour. Also, going forward the city will include all modes of transportation in its reports.

And while city representatives admitted there is no way to change the past, new methods will be used going forward.