MALIBU, Calif. — One month after four Pepperdine University students were killed when a car crashed into a series of parked vehicles on Pacific Coast Highway, Wednesday members of the traffic safety group Streets Are For Everyone are calling for improved safety measures along the coastal stretch after placing four "Ghost Tires" in Malibu in memory of the victims.

Approximately 100 people attended the gathering on Tuesday for the placement of the "ghost tires" at  23661 Pacific Coast Highway where those who knew the students shared their memories of the victims.

The memorial was inspired by the Ghost Bike project, in which roadside memorials are placed where a cyclist has been killed or severely injured by the driver of a motor vehicle. That project began in St. Louis in 2002. Ghost Tires are white-painted tires installed on the side of a road with the name and date of the person killed by a speeding driver.

Vigil attendees signed the tires and had a moment of silence for the students.

Niamh Rolston, Peyton Stewart, Asha Weir and Deslyn Williams, all in their 20s and seniors at Pepperdine's Seaver College of Liberal Arts, were killed Oct. 17 while standing or walking in the 21600 block of PCH around 8:30 p.m.

"Deslyn would do anything for the people she loved,"  Bridget Thompson, a roommate of three of the victims, said at the ceremony. "Niamh was pure joy and love personified, Asha was the most emotionally intelligent person I've ever met, Peyton was everything good. So nurturing, so kind."

David Rolston, Niamh's father, said, "Let's have my daughter and her three beautiful friends be the last ones."

The ghost tires initiative was created in August by the nonprofit traffic safety group Streets Are For Everyone. Ghost Tires are white-painted tires installed on the side of a road with the name and date of the person killed by a speeding driver.

"A ghost tire is a white painted tire that is an artistic pop-up memorial that symbolizes a person whose life has been taken because of a speeding driver," said Damian Kevitt, executive director of Streets Are For Everyone. "We were not able to put the tires where the crash actually happened because of how dangerous the area is."

The driver in the crash that claimed the lives of the Pepperdine students, 22-year-old Fraser Bohm of Malibu, was arrested on suspicion of murder and other accounts, and is out on bail.

Bohm was driving a dark-colored, four-door sedan westbound on PCH, apparently at high speed, when he swerved onto the north shoulder of the road and slammed into three parked vehicles, heavily damaging all of them and leaving one on its side, authorities said.

"Subsequently, those vehicles hit four female adults standing on the side of the roadway near the parked vehicles," Los Angeles County Sheriff's Capt. Jennifer Seetoo said. "The four females were pronounced dead at the scene."

Bohm suffered minor scratches and bruises.