CHP Gathers Data at School Bus Crash Site : Investigation: Another bus is put through paces at San Marcos intersection, whose signal is called complex but efficient.

Charles Laizure usually supervises the bus drivers in the San Marcos Unified School District, but Thursday he took the helm himself, making several runs at a left turn that had ended in a fatality earlier this week.

Laizure, director of transportation for the district, drove a bus of the same make and model as the one struck by a motor home Tuesday as it was making the turn, taking the life of 13-year-old Jennifer Loscher and injuring 13 other junior high school students.

A team of California Highway Patrol investigators videotaped and timed the bus as it made several runs at various speeds, while a passel of media and onlookers gathered.

“With the raw numbers we get this morning, we will be able to calculate acceleration rates of the bus on that particular morning,” said Sgt. Jim Waterbury of the CHP’s Multi-Disciplinary Accident Investigation Team, as he stood at Mission Road and Mulberry Drive, where debris from the crash still sat near the curb.

Investigators also measured skid marks from the crash and will analyze other physical evidence, such as damage to the vehicles, to determine the speed of the motor home at the time of the accident.

“We will be able to reconstruct the travel of the bus and the motor home and their positions second by second as they approached the intersection,” Waterbury said.

Under a “full-throttle, rapid acceleration,” Waterbury said, the bus reached a top speed of 17 m.p.h. before reaching the point where the accident occurred.

The accident took place at an intersection guided by an unusual and complex left-turn signal that some have blamed for numerous accidents since the light was installed in October.

The “cluster signal” gives drivers turning left a green arrow during times of heavy traffic, assuring them that opposing cars have a red light.

During times of light traffic, however, the signal is designed to give left-turning drivers a green circle, requiring that the driver yield to oncoming traffic before turning.

Traffic engineers said the system, called “protective-permissive,” has been widely used in Orange and Los Angeles counties, as well as in other states.

“It’s a perfectly legal configuration of signals,” said Hank Mohle, a La Habra traffic engineer. “The bottom line of it is for efficiency.”

Mohle and others said studies have shown that in the long run this type of traffic signal is as safe as a normal traffic light at which drivers making a left turn must yield to oncoming traffic.

“They can be very effective,” said Jim Sommers of Weston Pringle & Associates, a Fullerton-based firm. “A lot of motorists, once they understand how they work, they really like them.”

Traffic engineers agreed that it takes time for drivers to get accustomed to the new system.

“It’s a public education problem we have, I think,” Mohle said.

The CHP said the final report on the accident will take about a month, and San Marcos officials are waiting for the results and are also conducting a study of their own.

“We’ll certainly be taking a look at the CHP report to see if there are any results or recommendations that we can take advantage of,” said Rick Gittings, San Marcos city manager.

Memorial services for Jennifer Loscher, the daughter of San Marcos City Councilman Mark Loscher, will be held at noon Monday at St. Mark’s Catholic Church in San Marcos. The school district has scheduled a half-day of classes at San Marcos Junior High and Woodland Park Elementary School to allow students and staff members to attend the service.

Two injured children remained hospitalized at Children’s Hospital Thursday, both in fair condition, spokesman Mark Morelli said. Steven Schneider, 13, was moved out of the intensive care unit Thursday.

“Both are recovering quite nicely; both are awake and alert and talking to their parents and appear headed toward a complete recovery,” Morelli said.

Laizure, the school transportation director, said the school bus route on which the accident took place was redirected around the intersection Wednesday and Thursday because of the number of media cameras in the area.

Laizure said the redirection had nothing to do with safety concerns and that the intersection, along with another that has a similar traffic light, cannot be eliminated from bus routes.

The driver of the bus, Dawn Wynne, has gone on vacation, Laizure said.

“She’s off until she wants to return,” Laizure said of Wynne, who has had an unblemished driving record in her five years with the district. “As soon as she feels like coming back, she’s perfectly suited to come back at any time.”