According to business owners, nearly a dozen drivers have slid off the northbound onramp from Bonita Avenue and the Arrow Highway, sending their vehicles tumbling down.
Surveillance video shared with Eyewitness News captured an SUV sliding off the onramp and rolling over multiple times. It happened around 5 p.m. on Wednesday.
Cameras captured the vehicle rolling over, smashing through a fence below and stopping after damaging a car in the parking lot.
"I was working and I ran out the back because I thought something happened, like, in the back area. I saw the car was tumbled over there so I ran over there," said Andrew Rueda, who witnessed the accident. "By the time I got there, luckily there was like five people helping the guy get out. Luckily, he wasn't hurt too bad, he just had a little gash on his head."
Rueda says his family's business has been in the area for several years and he's seen multiple cars slide off the freeway.
"Personally, like 10 times, either coming off the side or them, like, a little action off the top, but it's always just something when it rains," he explained of the tricky onramp. "There's probably been many more that I have not seen."
He said vehicles simply slide off the hillside and roll over.
"They roll over, sometimes they go through the fence and luckily, there's been no crazy injuries but that's what we want to prevent," he said.
Deborah Briones, another business owner, said she warns customers ahead of time.
"It's crazy," she said. "We tell a lot of people not to park back there because in that area, where there's a hole in the fence, because they could just fly over and hit their car."
An employee of a hair salon shared cell phone video of a recent accident in the same area that occurred about a month ago. In that incident, a vehicle hit a light pole, preventing it from rolling down the hillside.
However, debris did cause damage the employee's car in the parking lot below.
Rueda is urging drivers using the onramp to slow down when coming around the corner, especially in severe weather conditions.
"A guard rail would help a lot because if it was there, they would just bounce off it and be a much safer accident," he said.
Caltrans said it plans to investigate the issue and issued the following statement:
"As increasing the safety on California's roadway system is Caltrans' top priority, Caltrans transportation engineers will review the area to determine potential safety improvement needs, per standard practice. Factors that will be considered during this evaluation will include current roadway conditions, traffic patterns, typical driver behavior, and a review of any traffic incidents or crashes, among other factors. Upon completion of the review, Caltrans will determine next steps."
Meanwhile, the city of San Dimas issued the following statement:
"We entrust that Caltrans will conduct a thorough review and resolve the issues raised. The City of San Dimas is willing to partner and assist Caltrans to ensure driver safety in our community."