
Most safety equipment on vehicles originated because of accidents. Underride bars, the safety device attached to the backs of semi-trucks and trailers, were the result of one such accident.
At around 1 a.m. on June 29, 1967, 40-year-old attorney Samuel “Sam” Brody; 20-year-old pre-law student Ronnie Harrison; 34-year-old Vera Jayne Palmer; three of Vera’s children: three-year-old Marie, six-year-old Zoltan, and eight-year-old Mickey Jr., along with their four dogs, left Biloxi, Mississippi, and began the 100-mile trip along US-90 to New Orleans. The three adults and two chihuahuas rode on front seat of the gray 1966 Buick Electra sedan, and the three children and two more chihuahuas slept in the back seat. At about 2:25 a.m., Ronnie drove the car along an extended straight stretch of the Chef Menteur Highway through the marsh which separated Lake Pontchartrain and the Gulf of Mexico. Mosquitos have always plagued the marsh during the summertime, and New Orleans city employees sprayed insecticide fog from city trucks in the never-ending battle for control. These workers sprayed insecticide fog during the night to avoid the heavy daytime traffic because they had to travel at slow speeds along the two-lane highway.
Forty three-year-old Richard Rambo was driving an 18-wheeler in the same direction on Chef Menteur Highway some distance ahead of the gray Buick when he saw a white cloud emanating from the slow-driving fogging truck. Rather than depressing the brake pedal which would have illuminated the brake lights, Richard removed his foot from the accelerator pedal and the “jake brake” slowed the truck and trailer to about 30 miles per hour. In the car, which was traveling about 70 miles per hour, Ronnie failed to notice that the truck and trailer had slowed significantly. He never hit the brakes. The car drove under the rear of the trailer with such a tremendous impact that it peeled the top off of the sedan. The car stopped when its front end struck the back tires of the trailer. Ronnie, Sam, Vera, and the two chihuahuas in the front seat were killed instantly. Vera’s children and the two chihuahuas in the back seat were injured but ultimately survived.
In 1968, the year after the deadly crash, the National Highway Traffic Safety Administration made it mandatory that all commercial trailers be equipped with large metal guards to prevent cars from driving under the rear of semi-trucks and trailers. Although technically called underride bars, the safety bars were nicknamed after Vera Jayne Palmer. You see, Vera Jayne Palmer was a famous actress, Playboy Playmate, and sex symbol of the 1950s and 60s. The world knows her by her married name, Jayne Mansfield. Because of the car crash that claimed her life, underride bars are commonly referred to as “Mansfield Bars.”
Sources:
1. The Shreveport Times, June 30, 1967, p.18.
2. Scott Armstrong, “The Dangers of Underride Truck Accidents, AKA Mansfield Bars,” February 14, 2025, https://albtriallawyers.













