Seventh grader’s project weighs in on vehicle speed signs

Seventh grader’s project weighs in on vehicle speed signs
Motorists along Quail Gardens Drive have their speed monitored by radar signs. Christopher Kulick, a seventh grader at The Rhoades School in Encinitas, studied the signs’ effectiveness for a science project. Photo by Tony Cagala

ENCINITAS — Christopher Kulick, a seventh grader at The Rhoades School in Encinitas, has a message for the city of Encinitas regarding the vehicle speed feedback signs installed in his neighborhood to slow down traffic on Quail Gardens Drive.

They aren’t working.

But young Chris’ message is not one of conjecture and anecdotal recollections. It is one that is backed up by a scientific study and cold-hard math.

For a recent class science project, Chris, with some assistance from his father Tony, explored the effectiveness of the ubiquitous signs along Quail Gardens Drive and, by using information from the city and his own field study of over 400 vehicles, concluded that vehicles are actually traveling faster along the street than before the signs were erected.

He presented his findings to the Encinitas Traffic and Public Safety Commission meeting on Feb. 8.

“It basically proved what I felt was going on since the signs went up,” Chris said. “I always felt that the cars were going faster than they were before.”

The vehicle speed feedback signs were part of a series of measures taken by the city to slow down traffic along both Quail Gardens and Saxony Road, which runs parallel to Quail Gardens between Encinitas and Leucadia boulevards. Neighbors and community stakeholders — including the Encinitas Union School District, Leichtag Foundation, Magdalena Ecke YMCA, Seacrest Village, the San Diego Botanic Garden and the San Dieguito Heritage Museum — have long complained that vehicles speed down the streets using them to bypass traffic on Interstate 5 during rush hour.

In 2015, the group of stakeholders worked with the city to successfully implement traffic calming measures along segments of the streets. On Quail Gardens, the city enacted a 25-mile-per-hour speed limit in the area near the school district’s new farm lab, and installed a crosswalk with safety lights in front of the farm lab.

On Saxony, the city recently enacted a 25-miles-per-hour “senior zone” in the area immediately adjacent to Seacrest and the YMCA. Construction of a similar crosswalk, which will bridge the two locations, was also completed in 2015.

For three months, Chris performed his study, using the scientific method as a roadmap to arrive at his conclusions. For the field study, Chris and his father, Tony, took two sets of measurements: they recorded the 85th percentile speed (the speed that 85 percent of vehicles traveled) of vehicles from the four speed signs, and then used a radar gun to measure the speed after they passed the signs on both sides of the street.

The findings were telling:

* The 85th percentile speed at the four signs ranged from a low speed of 43 miles per hour at the first northbound sign to 45 miles per hour at the second southbound sign. This means that on average, vehicles were travelling anywhere between three and five miles per hour faster than the posted speed limit of 40 miles per hour.

*Only 18 percent of vehicles that passed the first northbound sign slowed down after the sign, while 46 percent of drivers increased their speed and 36 percent maintained their speed.

* Drivers slowed down a bit more on the southbound side of the road, as 24.5 percent of the drivers slowed down after passing the speed sign, while 18.4 percent of the drivers sped up and 57.1 percent maintained their speed.

“The results of this study indicate that the signs do not result in the majority of drivers reducing their speeds,” Chris wrote in his report. “The results show the majority of vehicles maintaining the same or increased speeds.”

He noted that the southbound side of the street has a slight downhill decline, which might explain why more drivers slowed down after they passed the southbound signs.

Chris said he compared his data to information provided by the city’s Traffic Engineer Rob Blough, which showed that vehicle speeds at three of the four signs had faster 85th percentile speeds after the installation of the signs than before they were installed.

So, what can the city do to slow the speeds along his street?

Chris said he believed that reducing the street to one lane of traffic in each direction would be ideal, but in the absence of that, traffic calming devices such as roundabouts, speed humps, raised crosswalks and possibly stop signs.

“Making the street more narrow would slow the cars down, but the problem is that ambulances and fire trucks would have trouble driving the streets,” he said. “I also think that police should enforce the speed limits, but it’s so hard to do it on the street because there is no room to pull people over.”

Chris recently turned in his project to his science teacher, and is awaiting a grade. He is also hoping that the project will be picked to be exhibited at the Greater San Diego Science and Engineering Fair in mid-March.

“I hope that I can make it to state, but I’ll be satisfied if I can make it to the county fair,” said Chris, who said he wants to be an international correspondent when he grows up.

“I think he has a really good shot at it,” Tony said. “He’s put a lot of work into this project and it is very comprehensive and compelling. I am proud of the work that he has put into this project.”

2 Comments
  1. Jim 10 months ago

    Quail Gardens Drive already does have only one traffic lane in each direction along that stretch, fyi.

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