Recent testing suggests some dockless scooters with electric brakes are unable to stop on hills.
Philip Rosescu, a forensic engineer at WEXCO, tested a scooter model that uses electric brakes activated with the rider’s thumb to see whether it could come to a complete stop on a sloping road. The test was conducted as research for a lawsuit that Catherine Lerer, a Santa Monica personal injury attorney, is pursuing against Bird on behalf of clients who were injured after jumping off a scooter that was unable to stop on a hill.
One client was riding on down Bicknell Avenue toward the beach and tried to use her scooter’s electric brakes. When they failed to stop the scooter, she jumped off and hit the pavement, suffering a knee injury.
She was riding a Ninebot Segway ES2, a model that came out last fall and can reach 15.5 miles per hour. It has an electric handlebar brake and a rear fender brake activated with the foot. (Some iterations of the model lack a fender brake, Rosescu said.) Riders cannot control the intensity of the electric brake.
Rosescu tested the electric brake and the fender brake of an ES2 scooter on a hill in Playa del Rey. The maximum slope of the hill was 17 percent, or 9.65 degrees.
“It was steep, but you should be able to brake and stop on it,” Rosescu said. “If you were on a bike, you would be applying the brake the entire time.”
He brought the scooter up to maximum speed before entering the incline and applying the electric brakes.
“It didn’t really decelerate, it just kept going and only stopped after the hill leveled out,” he said. “You need to be able to stop if a car darts out in front of you and with e-brakes you just can’t.”
Rosescu repeated the test with the fender brake, and the scooter came to a stop in 47 feet on a 14 percent slope, or 7.97 degrees. He then used both the electric brake and the fender brake simultaneously, and the device stopped in 33 feet.
“On a hill, the e-brake is effectively useless,” he said. “It’s a hidden hazard.”
He also tested the scooter on a flat road, also on maximum speed. Using the electric brake, it came to a stop in 61 feet. With both the electric brake and the fender brake, it stopped in 25 feet.
While the fender brake is more effective, however, Rosescu believes a casual scooter rider may not think to use it. Fender brakes also present their own dangers: if you create enough friction with the back wheel when you press on the brake with your foot, the back wheel can lock up and fishtail, Rosescu said.
“If you need to come to a stop quickly, you need to use both the e-brake and the fender brake,” he said. “But the casual user may not know the fender brake exists and wouldn’t think to apply both brakes at the same time. It also takes coordination that many people don’t have to use both brakes simultaneously.”
Rosescu also tested another Bird model that has a rear cable brake activated by a handle, much like a bicycle. That model came to a stop on the hill in 33.5 feet. Rosescu said the cable brakes are the safest braking system for scooters because riders can control how hard or fast they decelerate.
He said he thinks scooter companies should have equipped their devices with cable brakes from the outset. At the very least, they should warn riders about braking on hills.
“These companies are fixing things based off the accidents that happen,” Rosescu said. “They should have done pilot testing to perfect the scooters and then put out models accommodating all the issues they’re dealing with now.”
Lerer said the findings indicate that the four companies licensed to operate in Santa Monica under the Shared Mobility pilot program are violating the terms of that agreement, which requires them to provide devices with durable brakes that are safe for a wide range of users.
Lime announced Feb. 23 that it had it had discovered a software bug that applied brakes to the front wheels of scooters if they hit a pothole or other obstacle while riding downhill at top speed. Riders have been thrown off of scooters because of the problem in New Zealand, Switzerland and Texas.
Bird, Lime and Jump could not be reached for comment.
“Safety is Lyft’s top priority, and we have built safety processes and guidance into and throughout the Lyft bikes and scooter experience,” a Lyft spokesperson said. “This includes a dedicated team on the ground to collect and maintain scooters in order to ensure that any available scooter is in good, operating condition.”
The City of Santa Monica was unable to provide information on whether it has tested the safety of electric brakes on scooters in the Shared Mobility program by press time.